While the set_msix() callback function in pcie-cadence-ep writes the
Table Size field correctly (N-1), the calculation of the PBA offset
is wrong because it calculates space for (N-1) entries instead of N.
This results in e.g. the following error when using QEMU with PCI
passthrough on a device which relies on the PCI endpoint subsystem:
failed to add PCI capability 0x11[0x50]@0xb0: table & pba overlap, or they don't fit in BARs, or don't align
Fix the calculation of PBA offset in the MSI-X capability.
Cc: stable(a)vger.kernel.org
Fixes: 3ef5d16f50f8 ("PCI: cadence: Add MSI-X support to Endpoint driver")
Reviewed-by: Wilfred Mallawa <wilfred.mallawa(a)wdc.com>
Reviewed-by: Damien Le Moal <dlemoal(a)kernel.org>
Signed-off-by: Niklas Cassel <cassel(a)kernel.org>
---
drivers/pci/controller/cadence/pcie-cadence-ep.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index 599ec4b1223e..112ae200b393 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -292,13 +292,14 @@ static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u8 vfn,
struct cdns_pcie *pcie = &ep->pcie;
u32 cap = CDNS_PCIE_EP_FUNC_MSIX_CAP_OFFSET;
u32 val, reg;
+ u16 actual_interrupts = interrupts + 1;
fn = cdns_pcie_get_fn_from_vfn(pcie, fn, vfn);
reg = cap + PCI_MSIX_FLAGS;
val = cdns_pcie_ep_fn_readw(pcie, fn, reg);
val &= ~PCI_MSIX_FLAGS_QSIZE;
- val |= interrupts;
+ val |= interrupts; /* 0's based value */
cdns_pcie_ep_fn_writew(pcie, fn, reg, val);
/* Set MSI-X BAR and offset */
@@ -308,7 +309,7 @@ static int cdns_pcie_ep_set_msix(struct pci_epc *epc, u8 fn, u8 vfn,
/* Set PBA BAR and offset. BAR must match MSI-X BAR */
reg = cap + PCI_MSIX_PBA;
- val = (offset + (interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
+ val = (offset + (actual_interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
cdns_pcie_ep_fn_writel(pcie, fn, reg, val);
return 0;
--
2.49.0
While the set_msix() callback function in pcie-designware-ep writes the
Table Size field correctly (N-1), the calculation of the PBA offset
is wrong because it calculates space for (N-1) entries instead of N.
This results in e.g. the following error when using QEMU with PCI
passthrough on a device which relies on the PCI endpoint subsystem:
failed to add PCI capability 0x11[0x50]@0xb0: table & pba overlap, or they don't fit in BARs, or don't align
Fix the calculation of PBA offset in the MSI-X capability.
Cc: stable(a)vger.kernel.org
Fixes: 83153d9f36e2 ("PCI: endpoint: Fix ->set_msix() to take BIR and offset as arguments")
Reviewed-by: Wilfred Mallawa <wilfred.mallawa(a)wdc.com>
Reviewed-by: Damien Le Moal <dlemoal(a)kernel.org>
Signed-off-by: Niklas Cassel <cassel(a)kernel.org>
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 1a0bf9341542..24026f3f3413 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -585,6 +585,7 @@ static int dw_pcie_ep_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
struct dw_pcie_ep_func *ep_func;
u32 val, reg;
+ u16 actual_interrupts = interrupts + 1;
ep_func = dw_pcie_ep_get_func_from_ep(ep, func_no);
if (!ep_func || !ep_func->msix_cap)
@@ -595,7 +596,7 @@ static int dw_pcie_ep_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
reg = ep_func->msix_cap + PCI_MSIX_FLAGS;
val = dw_pcie_ep_readw_dbi(ep, func_no, reg);
val &= ~PCI_MSIX_FLAGS_QSIZE;
- val |= interrupts;
+ val |= interrupts; /* 0's based value */
dw_pcie_writew_dbi(pci, reg, val);
reg = ep_func->msix_cap + PCI_MSIX_TABLE;
@@ -603,7 +604,7 @@ static int dw_pcie_ep_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
dw_pcie_ep_writel_dbi(ep, func_no, reg, val);
reg = ep_func->msix_cap + PCI_MSIX_PBA;
- val = (offset + (interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
+ val = (offset + (actual_interrupts * PCI_MSIX_ENTRY_SIZE)) | bir;
dw_pcie_ep_writel_dbi(ep, func_no, reg, val);
dw_pcie_dbi_ro_wr_dis(pci);
--
2.49.0
First patch of the series fixes possible infinite loop.
Remaining three patches fixes address alignment issue observed
after "9382bc44b5f5 arm64: allow kmalloc() caches aligned to the
smaller cache_line_size()"
Patch-2 and patch-3 applies to stable version 6.6 onwards.
Patch-4 applies to stable version 6.12 onwards
Bharat Bhushan (4):
crypto: octeontx2: add timeout for load_fvc completion poll
crypto: octeontx2: Fix address alignment issue on ucode loading
crypto: octeontx2: Fix address alignment on CN10K A0/A1 and OcteonTX2
crypto: octeontx2: Fix address alignment on CN10KB and CN10KA-B0
.../marvell/octeontx2/otx2_cpt_reqmgr.h | 119 +++++++++++++-----
.../marvell/octeontx2/otx2_cptpf_ucode.c | 46 ++++---
2 files changed, 121 insertions(+), 44 deletions(-)
--
2.34.1
Keyboard and touchpad stopped working on several Apple Macbooks from the
year 2017 using kernel 6.12.xx . Until now I could only find this
discussion affirming the bug on Debian and Fedora:
https://github.com/Dunedan/mbp-2016-linux/issues/202
On siduction I also tried the more recent kernels 6.14.5 and mainline
6.15-rc4 (from Ubuntu) and the issue persisted with my testdevice
MacBookPro14,1 -- see the relevant output:
kernel: platform pxa2xx-spi.3: Adding to iommu group 20
kernel: input: Apple SPI Keyboard as
/devices/pci0000:00/0000:00:1e.3/pxa2xx-spi.3/spi_master/spi2/spi-APP000D:00/input/input0
kernel: DMAR: DRHD: handling fault status reg 3
kernel: DMAR: [DMA Read NO_PASID] Request device [00:1e.3] fault addr
0xffffa000 [fault reason 0x06] PTE Read access is not set
kernel: DMAR: DRHD: handling fault status reg 3
kernel: DMAR: [DMA Read NO_PASID] Request device [00:1e.3] fault addr
0xffffa000 [fault reason 0x06] PTE Read access is not set
kernel: applespi spi-APP000D:00: Error writing to device: 01 0e 00 00
kernel: DMAR: DRHD: handling fault status reg 3
kernel: DMAR: [DMA Read NO_PASID] Request device [00:1e.3] fault addr
0xffffa000 [fault reason 0x06] PTE Read access is not set
kernel: DMAR: DRHD: handling fault status reg 3
kernel: applespi spi-APP000D:00: Error writing to device: 01 0e 00 00
Many thanks,
Jörg Berkel
Hey,
I just saw that I was debited twice for my latest transaction on your website.
Transaction appears twice on my payment history, and I need to get a reversal for the duplicate transaction.
Please investigate this and fix the issue at your earliest convenience? I’d appreciate a reply as fast as possible.
Thank you for your help in advance. Eagerly awaiting your update.
Best regards,
Charles Edwards
From: Linus Torvalds <torvalds(a)linux-foundation.org>
[ Upstream commit 6bd23e0c2bb6c65d4f5754d1456bc9a4427fc59b ]
... and use it to limit the virtual terminals to just N_TTY. They are
kind of special, and in particular, the "con_write()" routine violates
the "writes cannot sleep" rule that some ldiscs rely on.
This avoids the
BUG: sleeping function called from invalid context at kernel/printk/printk.c:2659
when N_GSM has been attached to a virtual console, and gsmld_write()
calls con_write() while holding a spinlock, and con_write() then tries
to get the console lock.
Tested-by: Tetsuo Handa <penguin-kernel(a)i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby(a)kernel.org>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Daniel Starke <daniel.starke(a)siemens.com>
Reported-by: syzbot <syzbot+dbac96d8e73b61aa559c(a)syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=dbac96d8e73b61aa559c
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Link: https://lore.kernel.org/r/20240423163339.59780-1-torvalds@linux-foundation.…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
[Minor conflict resolved due to code context change. And also backport description
comments for struct tty_operations.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com>
Signed-off-by: He Zhe <zhe.he(a)windriver.com>
---
Verified the build test
---
drivers/tty/tty_ldisc.c | 6 +
drivers/tty/vt/vt.c | 10 ++
include/linux/tty_driver.h | 339 +++++++++++++++++++++++++++++++++++++
3 files changed, 355 insertions(+)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index c34c01579b75..1ab3c4eb3359 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -567,6 +567,12 @@ int tty_set_ldisc(struct tty_struct *tty, int disc)
goto out;
}
+ if (tty->ops->ldisc_ok) {
+ retval = tty->ops->ldisc_ok(tty, disc);
+ if (retval)
+ goto out;
+ }
+
old_ldisc = tty->ldisc;
/* Shutdown the old discipline. */
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index bd125ea5c51f..5b35ea7744a4 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3440,6 +3440,15 @@ static void con_cleanup(struct tty_struct *tty)
tty_port_put(&vc->port);
}
+/*
+ * We can't deal with anything but the N_TTY ldisc,
+ * because we can sleep in our write() routine.
+ */
+static int con_ldisc_ok(struct tty_struct *tty, int ldisc)
+{
+ return ldisc == N_TTY ? 0 : -EINVAL;
+}
+
static int default_color = 7; /* white */
static int default_italic_color = 2; // green (ASCII)
static int default_underline_color = 3; // cyan (ASCII)
@@ -3567,6 +3576,7 @@ static const struct tty_operations con_ops = {
.resize = vt_resize,
.shutdown = con_shutdown,
.cleanup = con_cleanup,
+ .ldisc_ok = con_ldisc_ok,
};
static struct cdev vc0_cdev;
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index c20431d8def8..9707328595df 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -244,6 +244,344 @@ struct tty_driver;
struct serial_icounter_struct;
struct serial_struct;
+/**
+ * struct tty_operations -- interface between driver and tty
+ *
+ * @lookup: ``struct tty_struct *()(struct tty_driver *self, struct file *,
+ * int idx)``
+ *
+ * Return the tty device corresponding to @idx, %NULL if there is not
+ * one currently in use and an %ERR_PTR value on error. Called under
+ * %tty_mutex (for now!)
+ *
+ * Optional method. Default behaviour is to use the @self->ttys array.
+ *
+ * @install: ``int ()(struct tty_driver *self, struct tty_struct *tty)``
+ *
+ * Install a new @tty into the @self's internal tables. Used in
+ * conjunction with @lookup and @remove methods.
+ *
+ * Optional method. Default behaviour is to use the @self->ttys array.
+ *
+ * @remove: ``void ()(struct tty_driver *self, struct tty_struct *tty)``
+ *
+ * Remove a closed @tty from the @self's internal tables. Used in
+ * conjunction with @lookup and @remove methods.
+ *
+ * Optional method. Default behaviour is to use the @self->ttys array.
+ *
+ * @open: ``int ()(struct tty_struct *tty, struct file *)``
+ *
+ * This routine is called when a particular @tty device is opened. This
+ * routine is mandatory; if this routine is not filled in, the attempted
+ * open will fail with %ENODEV.
+ *
+ * Required method. Called with tty lock held. May sleep.
+ *
+ * @close: ``void ()(struct tty_struct *tty, struct file *)``
+ *
+ * This routine is called when a particular @tty device is closed. At the
+ * point of return from this call the driver must make no further ldisc
+ * calls of any kind.
+ *
+ * Remark: called even if the corresponding @open() failed.
+ *
+ * Required method. Called with tty lock held. May sleep.
+ *
+ * @shutdown: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine is called under the tty lock when a particular @tty device
+ * is closed for the last time. It executes before the @tty resources
+ * are freed so may execute while another function holds a @tty kref.
+ *
+ * @cleanup: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine is called asynchronously when a particular @tty device
+ * is closed for the last time freeing up the resources. This is
+ * actually the second part of shutdown for routines that might sleep.
+ *
+ * @write: ``int ()(struct tty_struct *tty, const unsigned char *buf,
+ * int count)``
+ *
+ * This routine is called by the kernel to write a series (@count) of
+ * characters (@buf) to the @tty device. The characters may come from
+ * user space or kernel space. This routine will return the
+ * number of characters actually accepted for writing.
+ *
+ * May occur in parallel in special cases. Because this includes panic
+ * paths drivers generally shouldn't try and do clever locking here.
+ *
+ * Optional: Required for writable devices. May not sleep.
+ *
+ * @put_char: ``int ()(struct tty_struct *tty, unsigned char ch)``
+ *
+ * This routine is called by the kernel to write a single character @ch to
+ * the @tty device. If the kernel uses this routine, it must call the
+ * @flush_chars() routine (if defined) when it is done stuffing characters
+ * into the driver. If there is no room in the queue, the character is
+ * ignored.
+ *
+ * Optional: Kernel will use the @write method if not provided. Do not
+ * call this function directly, call tty_put_char().
+ *
+ * @flush_chars: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine is called by the kernel after it has written a
+ * series of characters to the tty device using @put_char().
+ *
+ * Optional. Do not call this function directly, call
+ * tty_driver_flush_chars().
+ *
+ * @write_room: ``unsigned int ()(struct tty_struct *tty)``
+ *
+ * This routine returns the numbers of characters the @tty driver
+ * will accept for queuing to be written. This number is subject
+ * to change as output buffers get emptied, or if the output flow
+ * control is acted.
+ *
+ * The ldisc is responsible for being intelligent about multi-threading of
+ * write_room/write calls
+ *
+ * Required if @write method is provided else not needed. Do not call this
+ * function directly, call tty_write_room()
+ *
+ * @chars_in_buffer: ``unsigned int ()(struct tty_struct *tty)``
+ *
+ * This routine returns the number of characters in the device private
+ * output queue. Used in tty_wait_until_sent() and for poll()
+ * implementation.
+ *
+ * Optional: if not provided, it is assumed there is no queue on the
+ * device. Do not call this function directly, call tty_chars_in_buffer().
+ *
+ * @ioctl: ``int ()(struct tty_struct *tty, unsigned int cmd,
+ * unsigned long arg)``
+ *
+ * This routine allows the @tty driver to implement device-specific
+ * ioctls. If the ioctl number passed in @cmd is not recognized by the
+ * driver, it should return %ENOIOCTLCMD.
+ *
+ * Optional.
+ *
+ * @compat_ioctl: ``long ()(struct tty_struct *tty, unsigned int cmd,
+ * unsigned long arg)``
+ *
+ * Implement ioctl processing for 32 bit process on 64 bit system.
+ *
+ * Optional.
+ *
+ * @set_termios: ``void ()(struct tty_struct *tty, struct ktermios *old)``
+ *
+ * This routine allows the @tty driver to be notified when device's
+ * termios settings have changed. New settings are in @tty->termios.
+ * Previous settings are passed in the @old argument.
+ *
+ * The API is defined such that the driver should return the actual modes
+ * selected. This means that the driver is responsible for modifying any
+ * bits in @tty->termios it cannot fulfill to indicate the actual modes
+ * being used.
+ *
+ * Optional. Called under the @tty->termios_rwsem. May sleep.
+ *
+ * @ldisc_ok: ``int ()(struct tty_struct *tty, int ldisc)``
+ *
+ * This routine allows the @tty driver to decide if it can deal
+ * with a particular @ldisc.
+ *
+ * Optional. Called under the @tty->ldisc_sem and @tty->termios_rwsem.
+ *
+ * @set_ldisc: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine allows the @tty driver to be notified when the device's
+ * line discipline is being changed. At the point this is done the
+ * discipline is not yet usable.
+ *
+ * Optional. Called under the @tty->ldisc_sem and @tty->termios_rwsem.
+ *
+ * @throttle: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that input buffers for the line
+ * discipline are close to full, and it should somehow signal that no more
+ * characters should be sent to the @tty.
+ *
+ * Serialization including with @unthrottle() is the job of the ldisc
+ * layer.
+ *
+ * Optional: Always invoke via tty_throttle_safe(). Called under the
+ * @tty->termios_rwsem.
+ *
+ * @unthrottle: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that it should signal that
+ * characters can now be sent to the @tty without fear of overrunning the
+ * input buffers of the line disciplines.
+ *
+ * Optional. Always invoke via tty_unthrottle(). Called under the
+ * @tty->termios_rwsem.
+ *
+ * @stop: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that it should stop outputting
+ * characters to the tty device.
+ *
+ * Called with @tty->flow.lock held. Serialized with @start() method.
+ *
+ * Optional. Always invoke via stop_tty().
+ *
+ * @start: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that it resumed sending
+ * characters to the @tty device.
+ *
+ * Called with @tty->flow.lock held. Serialized with stop() method.
+ *
+ * Optional. Always invoke via start_tty().
+ *
+ * @hangup: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine notifies the @tty driver that it should hang up the @tty
+ * device.
+ *
+ * Optional. Called with tty lock held.
+ *
+ * @break_ctl: ``int ()(struct tty_struct *tty, int state)``
+ *
+ * This optional routine requests the @tty driver to turn on or off BREAK
+ * status on the RS-232 port. If @state is -1, then the BREAK status
+ * should be turned on; if @state is 0, then BREAK should be turned off.
+ *
+ * If this routine is implemented, the high-level tty driver will handle
+ * the following ioctls: %TCSBRK, %TCSBRKP, %TIOCSBRK, %TIOCCBRK.
+ *
+ * If the driver sets %TTY_DRIVER_HARDWARE_BREAK in tty_alloc_driver(),
+ * then the interface will also be called with actual times and the
+ * hardware is expected to do the delay work itself. 0 and -1 are still
+ * used for on/off.
+ *
+ * Optional: Required for %TCSBRK/%BRKP/etc. handling. May sleep.
+ *
+ * @flush_buffer: ``void ()(struct tty_struct *tty)``
+ *
+ * This routine discards device private output buffer. Invoked on close,
+ * hangup, to implement %TCOFLUSH ioctl and similar.
+ *
+ * Optional: if not provided, it is assumed there is no queue on the
+ * device. Do not call this function directly, call
+ * tty_driver_flush_buffer().
+ *
+ * @wait_until_sent: ``void ()(struct tty_struct *tty, int timeout)``
+ *
+ * This routine waits until the device has written out all of the
+ * characters in its transmitter FIFO. Or until @timeout (in jiffies) is
+ * reached.
+ *
+ * Optional: If not provided, the device is assumed to have no FIFO.
+ * Usually correct to invoke via tty_wait_until_sent(). May sleep.
+ *
+ * @send_xchar: ``void ()(struct tty_struct *tty, char ch)``
+ *
+ * This routine is used to send a high-priority XON/XOFF character (@ch)
+ * to the @tty device.
+ *
+ * Optional: If not provided, then the @write method is called under
+ * the @tty->atomic_write_lock to keep it serialized with the ldisc.
+ *
+ * @tiocmget: ``int ()(struct tty_struct *tty)``
+ *
+ * This routine is used to obtain the modem status bits from the @tty
+ * driver.
+ *
+ * Optional: If not provided, then %ENOTTY is returned from the %TIOCMGET
+ * ioctl. Do not call this function directly, call tty_tiocmget().
+ *
+ * @tiocmset: ``int ()(struct tty_struct *tty,
+ * unsigned int set, unsigned int clear)``
+ *
+ * This routine is used to set the modem status bits to the @tty driver.
+ * First, @clear bits should be cleared, then @set bits set.
+ *
+ * Optional: If not provided, then %ENOTTY is returned from the %TIOCMSET
+ * ioctl. Do not call this function directly, call tty_tiocmset().
+ *
+ * @resize: ``int ()(struct tty_struct *tty, struct winsize *ws)``
+ *
+ * Called when a termios request is issued which changes the requested
+ * terminal geometry to @ws.
+ *
+ * Optional: the default action is to update the termios structure
+ * without error. This is usually the correct behaviour. Drivers should
+ * not force errors here if they are not resizable objects (e.g. a serial
+ * line). See tty_do_resize() if you need to wrap the standard method
+ * in your own logic -- the usual case.
+ *
+ * @get_icount: ``int ()(struct tty_struct *tty,
+ * struct serial_icounter *icount)``
+ *
+ * Called when the @tty device receives a %TIOCGICOUNT ioctl. Passed a
+ * kernel structure @icount to complete.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ *
+ * @get_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
+ *
+ * Called when the @tty device receives a %TIOCGSERIAL ioctl. Passed a
+ * kernel structure @p (&struct serial_struct) to complete.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ * Do not call this function directly, call tty_tiocgserial().
+ *
+ * @set_serial: ``int ()(struct tty_struct *tty, struct serial_struct *p)``
+ *
+ * Called when the @tty device receives a %TIOCSSERIAL ioctl. Passed a
+ * kernel structure @p (&struct serial_struct) to set the values from.
+ *
+ * Optional: called only if provided, otherwise %ENOTTY will be returned.
+ * Do not call this function directly, call tty_tiocsserial().
+ *
+ * @show_fdinfo: ``void ()(struct tty_struct *tty, struct seq_file *m)``
+ *
+ * Called when the @tty device file descriptor receives a fdinfo request
+ * from VFS (to show in /proc/<pid>/fdinfo/). @m should be filled with
+ * information.
+ *
+ * Optional: called only if provided, otherwise nothing is written to @m.
+ * Do not call this function directly, call tty_show_fdinfo().
+ *
+ * @poll_init: ``int ()(struct tty_driver *driver, int line, char *options)``
+ *
+ * kgdboc support (Documentation/dev-tools/kgdb.rst). This routine is
+ * called to initialize the HW for later use by calling @poll_get_char or
+ * @poll_put_char.
+ *
+ * Optional: called only if provided, otherwise skipped as a non-polling
+ * driver.
+ *
+ * @poll_get_char: ``int ()(struct tty_driver *driver, int line)``
+ *
+ * kgdboc support (see @poll_init). @driver should read a character from a
+ * tty identified by @line and return it.
+ *
+ * Optional: called only if @poll_init provided.
+ *
+ * @poll_put_char: ``void ()(struct tty_driver *driver, int line, char ch)``
+ *
+ * kgdboc support (see @poll_init). @driver should write character @ch to
+ * a tty identified by @line.
+ *
+ * Optional: called only if @poll_init provided.
+ *
+ * @proc_show: ``int ()(struct seq_file *m, void *driver)``
+ *
+ * Driver @driver (cast to &struct tty_driver) can show additional info in
+ * /proc/tty/driver/<driver_name>. It is enough to fill in the information
+ * into @m.
+ *
+ * Optional: called only if provided, otherwise no /proc entry created.
+ *
+ * This structure defines the interface between the low-level tty driver and
+ * the tty routines. These routines can be defined. Unless noted otherwise,
+ * they are optional, and can be filled in with a %NULL pointer.
+ */
struct tty_operations {
struct tty_struct * (*lookup)(struct tty_driver *driver,
struct file *filp, int idx);
@@ -271,6 +609,7 @@ struct tty_operations {
void (*hangup)(struct tty_struct *tty);
int (*break_ctl)(struct tty_struct *tty, int state);
void (*flush_buffer)(struct tty_struct *tty);
+ int (*ldisc_ok)(struct tty_struct *tty, int ldisc);
void (*set_ldisc)(struct tty_struct *tty);
void (*wait_until_sent)(struct tty_struct *tty, int timeout);
void (*send_xchar)(struct tty_struct *tty, char ch);
--
2.34.1
The patch titled
Subject: mm/hugetlb: fix a deadlock with pagecache_folio and hugetlb_fault_mutex_table
has been added to the -mm mm-new branch. Its filename is
mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-new branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews. Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Gavin Guo <gavinguo(a)igalia.com>
Subject: mm/hugetlb: fix a deadlock with pagecache_folio and hugetlb_fault_mutex_table
Date: Tue, 13 May 2025 17:34:48 +0800
Fix a deadlock which can be triggered by an internal syzkaller [1]
reproducer and captured by bpftrace script [2] and its log [3] in this
scenario:
Process 1 Process 2
--- ---
hugetlb_fault
mutex_lock(B) // take B
filemap_lock_hugetlb_folio
filemap_lock_folio
__filemap_get_folio
folio_lock(A) // take A
hugetlb_wp
mutex_unlock(B) // release B
... hugetlb_fault
... mutex_lock(B) // take B
filemap_lock_hugetlb_folio
filemap_lock_folio
__filemap_get_folio
folio_lock(A) // blocked
unmap_ref_private
...
mutex_lock(B) // retake and blocked
This is a ABBA deadlock involving two locks:
- Lock A: pagecache_folio lock
- Lock B: hugetlb_fault_mutex_table lock
The deadlock occurs between two processes as follows:
1. The first process (let's call it Process 1) is handling a
copy-on-write (COW) operation on a hugepage via hugetlb_wp. Due to
insufficient reserved hugetlb pages, Process 1, owner of the reserved
hugetlb page, attempts to unmap a hugepage owned by another process
(non-owner) to satisfy the reservation. Before unmapping, Process 1
acquires lock B (hugetlb_fault_mutex_table lock) and then lock A
(pagecache_folio lock). To proceed with the unmap, it releases Lock B
but retains Lock A. After the unmap, Process 1 tries to reacquire Lock
B. However, at this point, Lock B has already been acquired by another
process.
2. The second process (Process 2) enters the hugetlb_fault handler
during the unmap operation. It successfully acquires Lock B
(hugetlb_fault_mutex_table lock) that was just released by Process 1,
but then attempts to acquire Lock A (pagecache_folio lock), which is
still held by Process 1.
As a result, Process 1 (holding Lock A) is blocked waiting for Lock B
(held by Process 2), while Process 2 (holding Lock B) is blocked waiting
for Lock A (held by Process 1), constructing a ABBA deadlock scenario.
The solution here is to unlock the pagecache_folio and provide the
pagecache_folio_unlocked variable to the caller to have the visibility
over the pagecache_folio status for subsequent handling.
The error message:
INFO: task repro_20250402_:13229 blocked for more than 64 seconds.
Not tainted 6.15.0-rc3+ #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:repro_20250402_ state:D stack:25856 pid:13229 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00004006
Call Trace:
<TASK>
__schedule+0x1755/0x4f50
schedule+0x158/0x330
schedule_preempt_disabled+0x15/0x30
__mutex_lock+0x75f/0xeb0
hugetlb_wp+0xf88/0x3440
hugetlb_fault+0x14c8/0x2c30
trace_clock_x86_tsc+0x20/0x20
do_user_addr_fault+0x61d/0x1490
exc_page_fault+0x64/0x100
asm_exc_page_fault+0x26/0x30
RIP: 0010:__put_user_4+0xd/0x20
copy_process+0x1f4a/0x3d60
kernel_clone+0x210/0x8f0
__x64_sys_clone+0x18d/0x1f0
do_syscall_64+0x6a/0x120
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x41b26d
</TASK>
INFO: task repro_20250402_:13229 is blocked on a mutex likely owned by task repro_20250402_:13250.
task:repro_20250402_ state:D stack:28288 pid:13250 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00000006
Call Trace:
<TASK>
__schedule+0x1755/0x4f50
schedule+0x158/0x330
io_schedule+0x92/0x110
folio_wait_bit_common+0x69a/0xba0
__filemap_get_folio+0x154/0xb70
hugetlb_fault+0xa50/0x2c30
trace_clock_x86_tsc+0x20/0x20
do_user_addr_fault+0xace/0x1490
exc_page_fault+0x64/0x100
asm_exc_page_fault+0x26/0x30
RIP: 0033:0x402619
</TASK>
INFO: task repro_20250402_:13250 blocked for more than 65 seconds.
Not tainted 6.15.0-rc3+ #24
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:repro_20250402_ state:D stack:28288 pid:13250 tgid:13228 ppid:3513 task_flags:0x400040 flags:0x00000006
Call Trace:
<TASK>
__schedule+0x1755/0x4f50
schedule+0x158/0x330
io_schedule+0x92/0x110
folio_wait_bit_common+0x69a/0xba0
__filemap_get_folio+0x154/0xb70
hugetlb_fault+0xa50/0x2c30
trace_clock_x86_tsc+0x20/0x20
do_user_addr_fault+0xace/0x1490
exc_page_fault+0x64/0x100
asm_exc_page_fault+0x26/0x30
RIP: 0033:0x402619
</TASK>
Showing all locks held in the system:
1 lock held by khungtaskd/35:
#0: ffffffff879a7440 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180
2 locks held by repro_20250402_/13229:
#0: ffff888017d801e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x37/0x300
#1: ffff888000fec848 (&hugetlb_fault_mutex_table[i]){+.+.}-{4:4}, at: hugetlb_wp+0xf88/0x3440
3 locks held by repro_20250402_/13250:
#0: ffff8880177f3d08 (vm_lock){++++}-{0:0}, at: do_user_addr_fault+0x41b/0x1490
#1: ffff888000fec848 (&hugetlb_fault_mutex_table[i]){+.+.}-{4:4}, at: hugetlb_fault+0x3b8/0x2c30
#2: ffff8880129500e8 (&resv_map->rw_sema){++++}-{4:4}, at: hugetlb_fault+0x494/0x2c30
Link: https://drive.google.com/file/d/1DVRnIW-vSayU5J1re9Ct_br3jJQU6Vpb/view?usp=… [1]
Link: https://github.com/bboymimi/bpftracer/blob/master/scripts/hugetlb_lock_debu… [2]
Link: https://drive.google.com/file/d/1bWq2-8o-BJAuhoHWX7zAhI6ggfhVzQUI/view?usp=… [3]
Link: https://lkml.kernel.org/r/20250513093448.592150-1-gavinguo@igalia.com
Fixes: 40549ba8f8e0 ("hugetlb: use new vma_lock for pmd sharing synchronization")
Signed-off-by: Gavin Guo <gavinguo(a)igalia.com>
Cc: Hugh Dickins <hughd(a)google.com>
Cc: Florent Revest <revest(a)google.com>
Cc: Gavin Shan <gshan(a)redhat.com>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Oscar Salvador <osalvador(a)suse.de>
Cc: Byungchul Park <byungchul(a)sk.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/hugetlb.c | 33 ++++++++++++++++++++++++++++-----
1 file changed, 28 insertions(+), 5 deletions(-)
--- a/mm/hugetlb.c~mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table
+++ a/mm/hugetlb.c
@@ -6131,7 +6131,8 @@ static void unmap_ref_private(struct mm_
* Keep the pte_same checks anyway to make transition from the mutex easier.
*/
static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
- struct vm_fault *vmf)
+ struct vm_fault *vmf,
+ bool *pagecache_folio_unlocked)
{
struct vm_area_struct *vma = vmf->vma;
struct mm_struct *mm = vma->vm_mm;
@@ -6229,6 +6230,22 @@ retry_avoidcopy:
folio_put(old_folio);
/*
+ * The pagecache_folio needs to be unlocked to avoid
+ * deadlock and we won't re-lock it in hugetlb_wp(). The
+ * pagecache_folio could be truncated after being
+ * unlocked. So its state should not be relied
+ * subsequently.
+ *
+ * Setting *pagecache_folio_unlocked to true allows the
+ * caller to handle any necessary logic related to the
+ * folio's unlocked state.
+ */
+ if (pagecache_folio) {
+ folio_unlock(pagecache_folio);
+ if (pagecache_folio_unlocked)
+ *pagecache_folio_unlocked = true;
+ }
+ /*
* Drop hugetlb_fault_mutex and vma_lock before
* unmapping. unmapping needs to hold vma_lock
* in write mode. Dropping vma_lock in read mode
@@ -6581,7 +6598,7 @@ static vm_fault_t hugetlb_no_page(struct
hugetlb_count_add(pages_per_huge_page(h), mm);
if ((vmf->flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
/* Optimization, do the COW without a second fault */
- ret = hugetlb_wp(folio, vmf);
+ ret = hugetlb_wp(folio, vmf, NULL);
}
spin_unlock(vmf->ptl);
@@ -6653,6 +6670,7 @@ vm_fault_t hugetlb_fault(struct mm_struc
struct hstate *h = hstate_vma(vma);
struct address_space *mapping;
int need_wait_lock = 0;
+ bool pagecache_folio_unlocked = false;
struct vm_fault vmf = {
.vma = vma,
.address = address & huge_page_mask(h),
@@ -6807,7 +6825,8 @@ vm_fault_t hugetlb_fault(struct mm_struc
if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) {
if (!huge_pte_write(vmf.orig_pte)) {
- ret = hugetlb_wp(pagecache_folio, &vmf);
+ ret = hugetlb_wp(pagecache_folio, &vmf,
+ &pagecache_folio_unlocked);
goto out_put_page;
} else if (likely(flags & FAULT_FLAG_WRITE)) {
vmf.orig_pte = huge_pte_mkdirty(vmf.orig_pte);
@@ -6824,10 +6843,14 @@ out_put_page:
out_ptl:
spin_unlock(vmf.ptl);
- if (pagecache_folio) {
+ /*
+ * If the pagecache_folio is unlocked in hugetlb_wp(), we skip
+ * folio_unlock() here.
+ */
+ if (pagecache_folio && !pagecache_folio_unlocked)
folio_unlock(pagecache_folio);
+ if (pagecache_folio)
folio_put(pagecache_folio);
- }
out_mutex:
hugetlb_vma_unlock_read(vma);
_
Patches currently in -mm which might be from gavinguo(a)igalia.com are
mm-hugetlb-fix-a-deadlock-with-pagecache_folio-and-hugetlb_fault_mutex_table.patch
V4: add read-back for non-DPG case. This is for protection
purpose as it is not used for producton.
On VCN v4.0.5 there is a race condition where the WPTR is not
updated after starting from idle when doorbell is used. Adding
register read-back after written at function end is to ensure
all register writes are done before they can be used.
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528
Cc: stable(a)vger.kernel.org
Signed-off-by: David (Ming Qiang) Wu <David.Wu3(a)amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Tested-by: Mario Limonciello <mario.limonciello(a)amd.com>
---
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
index ed00d35039c1..a09f9a2dd471 100644
--- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
+++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
@@ -1034,6 +1034,10 @@ static int vcn_v4_0_5_start_dpg_mode(struct amdgpu_vcn_inst *vinst,
ring->doorbell_index << VCN_RB1_DB_CTRL__OFFSET__SHIFT |
VCN_RB1_DB_CTRL__EN_MASK);
+ /* Keeping one read-back to ensure all register writes are done, otherwise
+ * it may introduce race conditions */
+ RREG32_SOC15(VCN, inst_idx, regVCN_RB1_DB_CTRL);
+
return 0;
}
@@ -1216,6 +1220,10 @@ static int vcn_v4_0_5_start(struct amdgpu_vcn_inst *vinst)
WREG32_SOC15(VCN, i, regVCN_RB_ENABLE, tmp);
fw_shared->sq.queue_mode &= ~(FW_QUEUE_RING_RESET | FW_QUEUE_DPG_HOLD_OFF);
+ /* Keeping one read-back to ensure all register writes are done, otherwise
+ * it may introduce race conditions */
+ RREG32_SOC15(VCN, i, regVCN_RB_ENABLE);
+
return 0;
}
--
2.34.1
The series contains several small patches to fix various
issues in the pinctrl driver for Armada 3700.
Signed-off-by: Gabor Juhos <j4g8y7(a)gmail.com>
---
Gabor Juhos (7):
pinctrl: armada-37xx: use correct OUTPUT_VAL register for GPIOs > 31
pinctrl: armada-37xx: propagate error from armada_37xx_gpio_direction_output()
pinctrl: armada-37xx: set GPIO output value before setting direction
pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get()
pinctrl: armada-37xx: propagate error from armada_37xx_pmx_gpio_set_direction()
pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get_direction()
pinctrl: armada-37xx: propagate error from armada_37xx_pmx_set_by_name()
drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 35 ++++++++++++++++-------------
1 file changed, 20 insertions(+), 15 deletions(-)
---
base-commit: 82f2b0b97b36ee3fcddf0f0780a9a0825d52fec3
change-id: 20250512-pinctrl-a37xx-fixes-98fabc45cb11
Best regards,
--
Gabor Juhos <j4g8y7(a)gmail.com>
V2: not to add extra read-back in vcn_v4_0_5_start as there is a
read-back already. New comment for better understanding.
On VCN v4.0.5 there is a race condition where the WPTR is not
updated after starting from idle when doorbell is used. The read-back
of regVCN_RB1_DB_CTRL register after written is to ensure the
doorbell_index is updated before it can work properly.
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528
Cc: stable(a)vger.kernel.org
Signed-off-by: David (Ming Qiang) Wu <David.Wu3(a)amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello(a)amd.com>
Tested-by: Mario Limonciello <mario.limonciello(a)amd.com>
Reviewed-by: Alex Deucher <alexander.deucher(a)amd.com>
---
drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
index ed00d35039c1..e55b76d71367 100644
--- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
+++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
@@ -1034,6 +1034,10 @@ static int vcn_v4_0_5_start_dpg_mode(struct amdgpu_vcn_inst *vinst,
ring->doorbell_index << VCN_RB1_DB_CTRL__OFFSET__SHIFT |
VCN_RB1_DB_CTRL__EN_MASK);
+ /* Keeping one read-back to ensure all register writes are done, otherwise
+ * it may introduce race conditions */
+ RREG32_SOC15(VCN, inst_idx, regVCN_RB1_DB_CTRL);
+
return 0;
}
--
2.34.1
From: Johannes Berg <johannes.berg(a)intel.com>
[ Upstream commit 9ad7974856926129f190ffbe3beea78460b3b7cc ]
If it looks like there's another subframe in the A-MSDU
but the header isn't fully there, we can end up reading
data out of bounds, only to discard later. Make this a
bit more careful and check if the subframe header can
even be present.
Reported-by: syzbot+d050d437fe47d479d210(a)syzkaller.appspotmail.com
Link: https://msgid.link/20240226203405.a731e2c95e38.I82ce7d8c0cc8970ce29d0a39fdc…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
[Minor conflict resolved due to code context change. And routine
ieee80211_is_valid_amsdu is introduced by commit fe4a6d2db3ba
("wifi: mac80211: implement support for yet another mesh A-MSDU format")
after 6.4.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com>
Signed-off-by: He Zhe <zhe.he(a)windriver.com>
---
Verified the build test
---
net/wireless/util.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 6ebc6567b287..0fd48361e3e1 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -751,24 +751,27 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
struct sk_buff *frame = NULL;
u16 ethertype;
u8 *payload;
- int offset = 0, remaining;
+ int offset = 0;
struct ethhdr eth;
bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb);
bool reuse_skb = false;
bool last = false;
while (!last) {
+ int remaining = skb->len - offset;
unsigned int subframe_len;
int len;
u8 padding;
+ if (sizeof(eth) > remaining)
+ goto purge;
+
skb_copy_bits(skb, offset, ð, sizeof(eth));
len = ntohs(eth.h_proto);
subframe_len = sizeof(struct ethhdr) + len;
padding = (4 - subframe_len) & 0x3;
/* the last MSDU has no padding */
- remaining = skb->len - offset;
if (subframe_len > remaining)
goto purge;
/* mitigate A-MSDU aggregation injection attacks */
--
2.34.1
From: Filipe Manana <fdmanana(a)suse.com>
commit a0f0cf8341e34e5d2265bfd3a7ad68342da1e2aa upstream.
When using the flushoncommit mount option, during almost every transaction
commit we trigger a warning from __writeback_inodes_sb_nr():
$ cat fs/fs-writeback.c:
(...)
static void __writeback_inodes_sb_nr(struct super_block *sb, ...
{
(...)
WARN_ON(!rwsem_is_locked(&sb->s_umount));
(...)
}
(...)
The trace produced in dmesg looks like the following:
[947.473890] WARNING: CPU: 5 PID: 930 at fs/fs-writeback.c:2610 __writeback_inodes_sb_nr+0x7e/0xb3
[947.481623] Modules linked in: nfsd nls_cp437 cifs asn1_decoder cifs_arc4 fscache cifs_md4 ipmi_ssif
[947.489571] CPU: 5 PID: 930 Comm: btrfs-transacti Not tainted 95.16.3-srb-asrock-00001-g36437ad63879 #186
[947.497969] RIP: 0010:__writeback_inodes_sb_nr+0x7e/0xb3
[947.502097] Code: 24 10 4c 89 44 24 18 c6 (...)
[947.519760] RSP: 0018:ffffc90000777e10 EFLAGS: 00010246
[947.523818] RAX: 0000000000000000 RBX: 0000000000963300 RCX: 0000000000000000
[947.529765] RDX: 0000000000000000 RSI: 000000000000fa51 RDI: ffffc90000777e50
[947.535740] RBP: ffff888101628a90 R08: ffff888100955800 R09: ffff888100956000
[947.541701] R10: 0000000000000002 R11: 0000000000000001 R12: ffff888100963488
[947.547645] R13: ffff888100963000 R14: ffff888112fb7200 R15: ffff888100963460
[947.553621] FS: 0000000000000000(0000) GS:ffff88841fd40000(0000) knlGS:0000000000000000
[947.560537] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[947.565122] CR2: 0000000008be50c4 CR3: 000000000220c000 CR4: 00000000001006e0
[947.571072] Call Trace:
[947.572354] <TASK>
[947.573266] btrfs_commit_transaction+0x1f1/0x998
[947.576785] ? start_transaction+0x3ab/0x44e
[947.579867] ? schedule_timeout+0x8a/0xdd
[947.582716] transaction_kthread+0xe9/0x156
[947.585721] ? btrfs_cleanup_transaction.isra.0+0x407/0x407
[947.590104] kthread+0x131/0x139
[947.592168] ? set_kthread_struct+0x32/0x32
[947.595174] ret_from_fork+0x22/0x30
[947.597561] </TASK>
[947.598553] ---[ end trace 644721052755541c ]---
This is because we started using writeback_inodes_sb() to flush delalloc
when committing a transaction (when using -o flushoncommit), in order to
avoid deadlocks with filesystem freeze operations. This change was made
by commit ce8ea7cc6eb313 ("btrfs: don't call btrfs_start_delalloc_roots
in flushoncommit"). After that change we started producing that warning,
and every now and then a user reports this since the warning happens too
often, it spams dmesg/syslog, and a user is unsure if this reflects any
problem that might compromise the filesystem's reliability.
We can not just lock the sb->s_umount semaphore before calling
writeback_inodes_sb(), because that would at least deadlock with
filesystem freezing, since at fs/super.c:freeze_super() sync_filesystem()
is called while we are holding that semaphore in write mode, and that can
trigger a transaction commit, resulting in a deadlock. It would also
trigger the same type of deadlock in the unmount path. Possibly, it could
also introduce some other locking dependencies that lockdep would report.
To fix this call try_to_writeback_inodes_sb() instead of
writeback_inodes_sb(), because that will try to read lock sb->s_umount
and then will only call writeback_inodes_sb() if it was able to lock it.
This is fine because the cases where it can't read lock sb->s_umount
are during a filesystem unmount or during a filesystem freeze - in those
cases sb->s_umount is write locked and sync_filesystem() is called, which
calls writeback_inodes_sb(). In other words, in all cases where we can't
take a read lock on sb->s_umount, writeback is already being triggered
elsewhere.
An alternative would be to call btrfs_start_delalloc_roots() with a
number of pages different from LONG_MAX, for example matching the number
of delalloc bytes we currently have, in which case we would end up
starting all delalloc with filemap_fdatawrite_wbc() and not with an
async flush via filemap_flush() - that is only possible after the rather
recent commit e076ab2a2ca70a ("btrfs: shrink delalloc pages instead of
full inodes"). However that creates a whole new can of worms due to new
lock dependencies, which lockdep complains, like for example:
[ 8948.247280] ======================================================
[ 8948.247823] WARNING: possible circular locking dependency detected
[ 8948.248353] 5.17.0-rc1-btrfs-next-111 #1 Not tainted
[ 8948.248786] ------------------------------------------------------
[ 8948.249320] kworker/u16:18/933570 is trying to acquire lock:
[ 8948.249812] ffff9b3de1591690 (sb_internal#2){.+.+}-{0:0}, at: find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.250638]
but task is already holding lock:
[ 8948.251140] ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.252018]
which lock already depends on the new lock.
[ 8948.252710]
the existing dependency chain (in reverse order) is:
[ 8948.253343]
-> #2 (&root->delalloc_mutex){+.+.}-{3:3}:
[ 8948.253950] __mutex_lock+0x90/0x900
[ 8948.254354] start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.254859] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.255408] btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.255942] btrfs_mksubvol+0x380/0x570 [btrfs]
[ 8948.256406] btrfs_mksnapshot+0x81/0xb0 [btrfs]
[ 8948.256870] __btrfs_ioctl_snap_create+0x17f/0x190 [btrfs]
[ 8948.257413] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs]
[ 8948.257961] btrfs_ioctl+0x1196/0x3630 [btrfs]
[ 8948.258418] __x64_sys_ioctl+0x83/0xb0
[ 8948.258793] do_syscall_64+0x3b/0xc0
[ 8948.259146] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.259709]
-> #1 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}:
[ 8948.260330] __mutex_lock+0x90/0x900
[ 8948.260692] btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.261234] btrfs_commit_transaction+0x32f/0xc00 [btrfs]
[ 8948.261766] btrfs_set_free_space_cache_v1_active+0x38/0x60 [btrfs]
[ 8948.262379] btrfs_start_pre_rw_mount+0x119/0x180 [btrfs]
[ 8948.262909] open_ctree+0x1511/0x171e [btrfs]
[ 8948.263359] btrfs_mount_root.cold+0x12/0xde [btrfs]
[ 8948.263863] legacy_get_tree+0x30/0x50
[ 8948.264242] vfs_get_tree+0x28/0xc0
[ 8948.264594] vfs_kern_mount.part.0+0x71/0xb0
[ 8948.265017] btrfs_mount+0x11d/0x3a0 [btrfs]
[ 8948.265462] legacy_get_tree+0x30/0x50
[ 8948.265851] vfs_get_tree+0x28/0xc0
[ 8948.266203] path_mount+0x2d4/0xbe0
[ 8948.266554] __x64_sys_mount+0x103/0x140
[ 8948.266940] do_syscall_64+0x3b/0xc0
[ 8948.267300] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 8948.267790]
-> #0 (sb_internal#2){.+.+}-{0:0}:
[ 8948.268322] __lock_acquire+0x12e8/0x2260
[ 8948.268733] lock_acquire+0xd7/0x310
[ 8948.269092] start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.269591] find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.270087] btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.270588] cow_file_range+0x17e/0x490 [btrfs]
[ 8948.271051] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.271586] writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.272071] __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.272579] extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.273113] extent_writepages+0x76/0x130 [btrfs]
[ 8948.273573] do_writepages+0xd2/0x1c0
[ 8948.273942] filemap_fdatawrite_wbc+0x68/0x90
[ 8948.274371] start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.274876] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.275417] flush_space+0x1f2/0x630 [btrfs]
[ 8948.275863] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.276438] process_one_work+0x252/0x5a0
[ 8948.276829] worker_thread+0x55/0x3b0
[ 8948.277189] kthread+0xf2/0x120
[ 8948.277506] ret_from_fork+0x22/0x30
[ 8948.277868]
other info that might help us debug this:
[ 8948.278548] Chain exists of:
sb_internal#2 --> &fs_info->delalloc_root_mutex --> &root->delalloc_mutex
[ 8948.279601] Possible unsafe locking scenario:
[ 8948.280102] CPU0 CPU1
[ 8948.280508] ---- ----
[ 8948.280915] lock(&root->delalloc_mutex);
[ 8948.281271] lock(&fs_info->delalloc_root_mutex);
[ 8948.281915] lock(&root->delalloc_mutex);
[ 8948.282487] lock(sb_internal#2);
[ 8948.282800]
*** DEADLOCK ***
[ 8948.283333] 4 locks held by kworker/u16:18/933570:
[ 8948.283750] #0: ffff9b3dc00a9d48 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.284609] #1: ffffa90349dafe70 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1d2/0x5a0
[ 8948.285637] #2: ffff9b3e14db5040 (&fs_info->delalloc_root_mutex){+.+.}-{3:3}, at: btrfs_start_delalloc_roots+0x97/0x2a0 [btrfs]
[ 8948.286674] #3: ffff9b3e09c717d8 (&root->delalloc_mutex){+.+.}-{3:3}, at: start_delalloc_inodes+0x78/0x400 [btrfs]
[ 8948.287596]
stack backtrace:
[ 8948.287975] CPU: 3 PID: 933570 Comm: kworker/u16:18 Not tainted 5.17.0-rc1-btrfs-next-111 #1
[ 8948.288677] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 8948.289649] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs]
[ 8948.290298] Call Trace:
[ 8948.290517] <TASK>
[ 8948.290700] dump_stack_lvl+0x59/0x73
[ 8948.291026] check_noncircular+0xf3/0x110
[ 8948.291375] ? start_transaction+0x228/0x6e0 [btrfs]
[ 8948.291826] __lock_acquire+0x12e8/0x2260
[ 8948.292241] lock_acquire+0xd7/0x310
[ 8948.292714] ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.293241] ? lock_is_held_type+0xea/0x140
[ 8948.293601] start_transaction+0x44c/0x6e0 [btrfs]
[ 8948.294055] ? find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294518] find_free_extent+0x141e/0x1590 [btrfs]
[ 8948.294957] ? _raw_spin_unlock+0x29/0x40
[ 8948.295312] ? btrfs_get_alloc_profile+0x124/0x290 [btrfs]
[ 8948.295813] btrfs_reserve_extent+0x14b/0x280 [btrfs]
[ 8948.296270] cow_file_range+0x17e/0x490 [btrfs]
[ 8948.296691] btrfs_run_delalloc_range+0x345/0x7a0 [btrfs]
[ 8948.297175] ? find_lock_delalloc_range+0x247/0x270 [btrfs]
[ 8948.297678] writepage_delalloc+0xb5/0x170 [btrfs]
[ 8948.298123] __extent_writepage+0x156/0x3c0 [btrfs]
[ 8948.298570] extent_write_cache_pages+0x263/0x460 [btrfs]
[ 8948.299061] extent_writepages+0x76/0x130 [btrfs]
[ 8948.299495] do_writepages+0xd2/0x1c0
[ 8948.299817] ? sched_clock_cpu+0xd/0x110
[ 8948.300160] ? lock_release+0x155/0x4a0
[ 8948.300494] filemap_fdatawrite_wbc+0x68/0x90
[ 8948.300874] ? do_raw_spin_unlock+0x4b/0xa0
[ 8948.301243] start_delalloc_inodes+0x17f/0x400 [btrfs]
[ 8948.301706] ? lock_release+0x155/0x4a0
[ 8948.302055] btrfs_start_delalloc_roots+0x194/0x2a0 [btrfs]
[ 8948.302564] flush_space+0x1f2/0x630 [btrfs]
[ 8948.302970] btrfs_async_reclaim_data_space+0x108/0x1b0 [btrfs]
[ 8948.303510] process_one_work+0x252/0x5a0
[ 8948.303860] ? process_one_work+0x5a0/0x5a0
[ 8948.304221] worker_thread+0x55/0x3b0
[ 8948.304543] ? process_one_work+0x5a0/0x5a0
[ 8948.304904] kthread+0xf2/0x120
[ 8948.305184] ? kthread_complete_and_exit+0x20/0x20
[ 8948.305598] ret_from_fork+0x22/0x30
[ 8948.305921] </TASK>
It all comes from the fact that btrfs_start_delalloc_roots() takes the
delalloc_root_mutex, in the transaction commit path we are holding a
read lock on one of the superblock's freeze semaphores (via
sb_start_intwrite()), the async reclaim task can also do a call to
btrfs_start_delalloc_roots(), which ends up triggering writeback with
calls to filemap_fdatawrite_wbc(), resulting in extent allocation which
in turn can call btrfs_start_transaction(), which will result in taking
the freeze semaphore via sb_start_intwrite(), forming a nasty dependency
on all those locks which can be taken in different orders by different
code paths.
So just adopt the simple approach of calling try_to_writeback_inodes_sb()
at btrfs_start_delalloc_flush().
Link: https://lore.kernel.org/linux-btrfs/20220130005258.GA7465@cuci.nl/
Link: https://lore.kernel.org/linux-btrfs/43acc426-d683-d1b6-729d-c6bc4a2fff4d@gm…
Link: https://lore.kernel.org/linux-btrfs/6833930a-08d7-6fbc-0141-eb9cdfd6bb4d@gm…
Link: https://lore.kernel.org/linux-btrfs/20190322041731.GF16651@hungrycats.org/
Reviewed-by: Omar Sandoval <osandov(a)fb.com>
Signed-off-by: Filipe Manana <fdmanana(a)suse.com>
[ add more link reports ]
Signed-off-by: David Sterba <dsterba(a)suse.com>
[Minor context change fixed]
Signed-off-by: Zhi Yang <Zhi.Yang(a)windriver.com>
Signed-off-by: He Zhe <zhe.he(a)windriver.com>
---
Build test passed.
---
fs/btrfs/transaction.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 21a5a963c70e..8c0703f8037b 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2021,16 +2021,24 @@ static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans)
struct btrfs_fs_info *fs_info = trans->fs_info;
/*
- * We use writeback_inodes_sb here because if we used
+ * We use try_to_writeback_inodes_sb() here because if we used
* btrfs_start_delalloc_roots we would deadlock with fs freeze.
* Currently are holding the fs freeze lock, if we do an async flush
* we'll do btrfs_join_transaction() and deadlock because we need to
* wait for the fs freeze lock. Using the direct flushing we benefit
* from already being in a transaction and our join_transaction doesn't
* have to re-take the fs freeze lock.
+ *
+ * Note that try_to_writeback_inodes_sb() will only trigger writeback
+ * if it can read lock sb->s_umount. It will always be able to lock it,
+ * except when the filesystem is being unmounted or being frozen, but in
+ * those cases sync_filesystem() is called, which results in calling
+ * writeback_inodes_sb() while holding a write lock on sb->s_umount.
+ * Note that we don't call writeback_inodes_sb() directly, because it
+ * will emit a warning if sb->s_umount is not locked.
*/
if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) {
- writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC);
+ try_to_writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC);
} else {
struct btrfs_pending_snapshot *pending;
struct list_head *head = &trans->transaction->pending_snapshots;
--
2.34.1
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x ab00ddd802f80e31fc9639c652d736fe3913feae
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051243-handprint-impulse-c20a@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From ab00ddd802f80e31fc9639c652d736fe3913feae Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.tang(a)linux.alibaba.com>
Date: Wed, 23 Apr 2025 18:36:45 +0800
Subject: [PATCH] selftests/mm: compaction_test: support platform with huge
mount of memory
When running mm selftest to verify mm patches, 'compaction_test' case
failed on an x86 server with 1TB memory. And the root cause is that it
has too much free memory than what the test supports.
The test case tries to allocate 100000 huge pages, which is about 200 GB
for that x86 server, and when it succeeds, it expects it's large than 1/3
of 80% of the free memory in system. This logic only works for platform
with 750 GB ( 200 / (1/3) / 80% ) or less free memory, and may raise false
alarm for others.
Fix it by changing the fixed page number to self-adjustable number
according to the real number of free memory.
Link: https://lkml.kernel.org/r/20250423103645.2758-1-feng.tang@linux.alibaba.com
Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
Signed-off-by: Feng Tang <feng.tang(a)linux.alibaba.com>
Acked-by: Dev Jain <dev.jain(a)arm.com>
Reviewed-by: Baolin Wang <baolin.wang(a)linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang(a)inux.alibaba.com>
Cc: Shuah Khan <shuah(a)kernel.org>
Cc: Sri Jayaramappa <sjayaram(a)akamai.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 2c3a0eb6b22d..9bc4591c7b16 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -90,6 +90,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size,
int compaction_index = 0;
char nr_hugepages[20] = {0};
char init_nr_hugepages[24] = {0};
+ char target_nr_hugepages[24] = {0};
+ int slen;
snprintf(init_nr_hugepages, sizeof(init_nr_hugepages),
"%lu", initial_nr_hugepages);
@@ -106,11 +108,18 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size,
goto out;
}
- /* Request a large number of huge pages. The Kernel will allocate
- as much as it can */
- if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
- ksft_print_msg("Failed to write 100000 to /proc/sys/vm/nr_hugepages: %s\n",
- strerror(errno));
+ /*
+ * Request huge pages for about half of the free memory. The Kernel
+ * will allocate as much as it can, and we expect it will get at least 1/3
+ */
+ nr_hugepages_ul = mem_free / hugepage_size / 2;
+ snprintf(target_nr_hugepages, sizeof(target_nr_hugepages),
+ "%lu", nr_hugepages_ul);
+
+ slen = strlen(target_nr_hugepages);
+ if (write(fd, target_nr_hugepages, slen) != slen) {
+ ksft_print_msg("Failed to write %lu to /proc/sys/vm/nr_hugepages: %s\n",
+ nr_hugepages_ul, strerror(errno));
goto close_fd;
}
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 94cff94634e506a4a44684bee1875d2dbf782722
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051257-skater-skeleton-9a3d@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 94cff94634e506a4a44684bee1875d2dbf782722 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Date: Fri, 4 Apr 2025 15:31:16 +0200
Subject: [PATCH] clocksource/i8253: Use raw_spinlock_irqsave() in
clockevent_i8253_disable()
On x86 during boot, clockevent_i8253_disable() can be invoked via
x86_late_time_init -> hpet_time_init() -> pit_timer_init() which happens
with enabled interrupts.
If some of the old i8253 hardware is actually used then lockdep will notice
that i8253_lock is used in hard interrupt context. This causes lockdep to
complain because it observed the lock being acquired with interrupts
enabled and in hard interrupt context.
Make clockevent_i8253_disable() acquire the lock with
raw_spinlock_irqsave() to cure this.
[ tglx: Massage change log and use guard() ]
Fixes: c8c4076723dac ("x86/timer: Skip PIT initialization on modern chipsets")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/all/20250404133116.p-XRWJXf@linutronix.de
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
index 39f7c2d736d1..b603c25f3dfa 100644
--- a/drivers/clocksource/i8253.c
+++ b/drivers/clocksource/i8253.c
@@ -103,7 +103,7 @@ int __init clocksource_i8253_init(void)
#ifdef CONFIG_CLKEVT_I8253
void clockevent_i8253_disable(void)
{
- raw_spin_lock(&i8253_lock);
+ guard(raw_spinlock_irqsave)(&i8253_lock);
/*
* Writing the MODE register should stop the counter, according to
@@ -132,8 +132,6 @@ void clockevent_i8253_disable(void)
outb_p(0, PIT_CH0);
outb_p(0x30, PIT_MODE);
-
- raw_spin_unlock(&i8253_lock);
}
static int pit_shutdown(struct clock_event_device *evt)
From: Johannes Berg <johannes.berg(a)intel.com>
[ Upstream commit 9ad7974856926129f190ffbe3beea78460b3b7cc ]
If it looks like there's another subframe in the A-MSDU
but the header isn't fully there, we can end up reading
data out of bounds, only to discard later. Make this a
bit more careful and check if the subframe header can
even be present.
Reported-by: syzbot+d050d437fe47d479d210(a)syzkaller.appspotmail.com
Link: https://msgid.link/20240226203405.a731e2c95e38.I82ce7d8c0cc8970ce29d0a39fdc…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
[Minor conflict resolved due to code context change. And routine
ieee80211_is_valid_amsdu is introduced by commit fe4a6d2db3ba
("wifi: mac80211: implement support for yet another mesh A-MSDU format")
after 6.4.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com>
Signed-off-by: He Zhe <zhe.he(a)windriver.com>
---
Verified the build test
---
net/wireless/util.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 6ebc6567b287..0fd48361e3e1 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -751,24 +751,27 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
struct sk_buff *frame = NULL;
u16 ethertype;
u8 *payload;
- int offset = 0, remaining;
+ int offset = 0;
struct ethhdr eth;
bool reuse_frag = skb->head_frag && !skb_has_frag_list(skb);
bool reuse_skb = false;
bool last = false;
while (!last) {
+ int remaining = skb->len - offset;
unsigned int subframe_len;
int len;
u8 padding;
+ if (sizeof(eth) > remaining)
+ goto purge;
+
skb_copy_bits(skb, offset, ð, sizeof(eth));
len = ntohs(eth.h_proto);
subframe_len = sizeof(struct ethhdr) + len;
padding = (4 - subframe_len) & 0x3;
/* the last MSDU has no padding */
- remaining = skb->len - offset;
if (subframe_len > remaining)
goto purge;
/* mitigate A-MSDU aggregation injection attacks */
--
2.34.1
The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x f31fe8165d365379d858c53bef43254c7d6d1cfd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025051208-hardly-dole-1422@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f31fe8165d365379d858c53bef43254c7d6d1cfd Mon Sep 17 00:00:00 2001
From: Naman Jain <namjain(a)linux.microsoft.com>
Date: Fri, 2 May 2025 13:18:10 +0530
Subject: [PATCH] uio_hv_generic: Fix sysfs creation path for ring buffer
On regular bootup, devices get registered to VMBus first, so when
uio_hv_generic driver for a particular device type is probed,
the device is already initialized and added, so sysfs creation in
hv_uio_probe() works fine. However, when the device is removed
and brought back, the channel gets rescinded and the device again gets
registered to VMBus. However this time, the uio_hv_generic driver is
already registered to probe for that device and in this case sysfs
creation is tried before the device's kobject gets initialized
completely.
Fix this by moving the core logic of sysfs creation of ring buffer,
from uio_hv_generic to HyperV's VMBus driver, where the rest of the
sysfs attributes for the channels are defined. While doing that, make
use of attribute groups and macros, instead of creating sysfs
directly, to ensure better error handling and code flow.
Problematic path:
vmbus_process_offer (A new offer comes for the VMBus device)
vmbus_add_channel_work
vmbus_device_register
|-> device_register
| |...
| |-> hv_uio_probe
| |...
| |-> sysfs_create_bin_file (leads to a warning as
| the primary channel's kobject, which is used to
| create the sysfs file, is not yet initialized)
|-> kset_create_and_add
|-> vmbus_add_channel_kobj (initialization of the primary
channel's kobject happens later)
Above code flow is sequential and the warning is always reproducible in
this path.
Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel")
Cc: stable(a)kernel.org
Suggested-by: Saurabh Sengar <ssengar(a)linux.microsoft.com>
Suggested-by: Michael Kelley <mhklinux(a)outlook.com>
Reviewed-by: Michael Kelley <mhklinux(a)outlook.com>
Tested-by: Michael Kelley <mhklinux(a)outlook.com>
Reviewed-by: Dexuan Cui <decui(a)microsoft.com>
Signed-off-by: Naman Jain <namjain(a)linux.microsoft.com>
Link: https://lore.kernel.org/r/20250502074811.2022-2-namjain@linux.microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 29780f3a7478..0b450e53161e 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -477,4 +477,10 @@ static inline int hv_debug_add_dev_dir(struct hv_device *dev)
#endif /* CONFIG_HYPERV_TESTING */
+/* Create and remove sysfs entry for memory mapped ring buffers for a channel */
+int hv_create_ring_sysfs(struct vmbus_channel *channel,
+ int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel,
+ struct vm_area_struct *vma));
+int hv_remove_ring_sysfs(struct vmbus_channel *channel);
+
#endif /* _HYPERV_VMBUS_H */
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 8d3cff42bdbb..0f16a83cc2d6 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1802,6 +1802,27 @@ static ssize_t subchannel_id_show(struct vmbus_channel *channel,
}
static VMBUS_CHAN_ATTR_RO(subchannel_id);
+static int hv_mmap_ring_buffer_wrapper(struct file *filp, struct kobject *kobj,
+ const struct bin_attribute *attr,
+ struct vm_area_struct *vma)
+{
+ struct vmbus_channel *channel = container_of(kobj, struct vmbus_channel, kobj);
+
+ /*
+ * hv_(create|remove)_ring_sysfs implementation ensures that mmap_ring_buffer
+ * is not NULL.
+ */
+ return channel->mmap_ring_buffer(channel, vma);
+}
+
+static struct bin_attribute chan_attr_ring_buffer = {
+ .attr = {
+ .name = "ring",
+ .mode = 0600,
+ },
+ .size = 2 * SZ_2M,
+ .mmap = hv_mmap_ring_buffer_wrapper,
+};
static struct attribute *vmbus_chan_attrs[] = {
&chan_attr_out_mask.attr,
&chan_attr_in_mask.attr,
@@ -1821,6 +1842,11 @@ static struct attribute *vmbus_chan_attrs[] = {
NULL
};
+static struct bin_attribute *vmbus_chan_bin_attrs[] = {
+ &chan_attr_ring_buffer,
+ NULL
+};
+
/*
* Channel-level attribute_group callback function. Returns the permission for
* each attribute, and returns 0 if an attribute is not visible.
@@ -1841,9 +1867,24 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
return attr->mode;
}
+static umode_t vmbus_chan_bin_attr_is_visible(struct kobject *kobj,
+ const struct bin_attribute *attr, int idx)
+{
+ const struct vmbus_channel *channel =
+ container_of(kobj, struct vmbus_channel, kobj);
+
+ /* Hide ring attribute if channel's ring_sysfs_visible is set to false */
+ if (attr == &chan_attr_ring_buffer && !channel->ring_sysfs_visible)
+ return 0;
+
+ return attr->attr.mode;
+}
+
static const struct attribute_group vmbus_chan_group = {
.attrs = vmbus_chan_attrs,
- .is_visible = vmbus_chan_attr_is_visible
+ .bin_attrs = vmbus_chan_bin_attrs,
+ .is_visible = vmbus_chan_attr_is_visible,
+ .is_bin_visible = vmbus_chan_bin_attr_is_visible,
};
static const struct kobj_type vmbus_chan_ktype = {
@@ -1851,6 +1892,63 @@ static const struct kobj_type vmbus_chan_ktype = {
.release = vmbus_chan_release,
};
+/**
+ * hv_create_ring_sysfs() - create "ring" sysfs entry corresponding to ring buffers for a channel.
+ * @channel: Pointer to vmbus_channel structure
+ * @hv_mmap_ring_buffer: function pointer for initializing the function to be called on mmap of
+ * channel's "ring" sysfs node, which is for the ring buffer of that channel.
+ * Function pointer is of below type:
+ * int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel,
+ * struct vm_area_struct *vma))
+ * This has a pointer to the channel and a pointer to vm_area_struct,
+ * used for mmap, as arguments.
+ *
+ * Sysfs node for ring buffer of a channel is created along with other fields, however its
+ * visibility is disabled by default. Sysfs creation needs to be controlled when the use-case
+ * is running.
+ * For example, HV_NIC device is used either by uio_hv_generic or hv_netvsc at any given point of
+ * time, and "ring" sysfs is needed only when uio_hv_generic is bound to that device. To avoid
+ * exposing the ring buffer by default, this function is reponsible to enable visibility of
+ * ring for userspace to use.
+ * Note: Race conditions can happen with userspace and it is not encouraged to create new
+ * use-cases for this. This was added to maintain backward compatibility, while solving
+ * one of the race conditions in uio_hv_generic while creating sysfs.
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int hv_create_ring_sysfs(struct vmbus_channel *channel,
+ int (*hv_mmap_ring_buffer)(struct vmbus_channel *channel,
+ struct vm_area_struct *vma))
+{
+ struct kobject *kobj = &channel->kobj;
+
+ channel->mmap_ring_buffer = hv_mmap_ring_buffer;
+ channel->ring_sysfs_visible = true;
+
+ return sysfs_update_group(kobj, &vmbus_chan_group);
+}
+EXPORT_SYMBOL_GPL(hv_create_ring_sysfs);
+
+/**
+ * hv_remove_ring_sysfs() - remove ring sysfs entry corresponding to ring buffers for a channel.
+ * @channel: Pointer to vmbus_channel structure
+ *
+ * Hide "ring" sysfs for a channel by changing its is_visible attribute and updating sysfs group.
+ *
+ * Returns 0 on success or error code on failure.
+ */
+int hv_remove_ring_sysfs(struct vmbus_channel *channel)
+{
+ struct kobject *kobj = &channel->kobj;
+ int ret;
+
+ channel->ring_sysfs_visible = false;
+ ret = sysfs_update_group(kobj, &vmbus_chan_group);
+ channel->mmap_ring_buffer = NULL;
+ return ret;
+}
+EXPORT_SYMBOL_GPL(hv_remove_ring_sysfs);
+
/*
* vmbus_add_channel_kobj - setup a sub-directory under device/channels
*/
diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c
index 1b19b5647495..69c1df0f4ca5 100644
--- a/drivers/uio/uio_hv_generic.c
+++ b/drivers/uio/uio_hv_generic.c
@@ -131,15 +131,12 @@ static void hv_uio_rescind(struct vmbus_channel *channel)
vmbus_device_unregister(channel->device_obj);
}
-/* Sysfs API to allow mmap of the ring buffers
+/* Function used for mmap of ring buffer sysfs interface.
* The ring buffer is allocated as contiguous memory by vmbus_open
*/
-static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj,
- const struct bin_attribute *attr,
- struct vm_area_struct *vma)
+static int
+hv_uio_ring_mmap(struct vmbus_channel *channel, struct vm_area_struct *vma)
{
- struct vmbus_channel *channel
- = container_of(kobj, struct vmbus_channel, kobj);
void *ring_buffer = page_address(channel->ringbuffer_page);
if (channel->state != CHANNEL_OPENED_STATE)
@@ -149,15 +146,6 @@ static int hv_uio_ring_mmap(struct file *filp, struct kobject *kobj,
channel->ringbuffer_pagecount << PAGE_SHIFT);
}
-static const struct bin_attribute ring_buffer_bin_attr = {
- .attr = {
- .name = "ring",
- .mode = 0600,
- },
- .size = 2 * SZ_2M,
- .mmap = hv_uio_ring_mmap,
-};
-
/* Callback from VMBUS subsystem when new channel created. */
static void
hv_uio_new_channel(struct vmbus_channel *new_sc)
@@ -178,8 +166,7 @@ hv_uio_new_channel(struct vmbus_channel *new_sc)
/* Disable interrupts on sub channel */
new_sc->inbound.ring_buffer->interrupt_mask = 1;
set_channel_read_mode(new_sc, HV_CALL_ISR);
-
- ret = sysfs_create_bin_file(&new_sc->kobj, &ring_buffer_bin_attr);
+ ret = hv_create_ring_sysfs(new_sc, hv_uio_ring_mmap);
if (ret) {
dev_err(device, "sysfs create ring bin file failed; %d\n", ret);
vmbus_close(new_sc);
@@ -350,10 +337,18 @@ hv_uio_probe(struct hv_device *dev,
goto fail_close;
}
- ret = sysfs_create_bin_file(&channel->kobj, &ring_buffer_bin_attr);
- if (ret)
- dev_notice(&dev->device,
- "sysfs create ring bin file failed; %d\n", ret);
+ /*
+ * This internally calls sysfs_update_group, which returns a non-zero value if it executes
+ * before sysfs_create_group. This is expected as the 'ring' will be created later in
+ * vmbus_device_register() -> vmbus_add_channel_kobj(). Thus, no need to check the return
+ * value and print warning.
+ *
+ * Creating/exposing sysfs in driver probe is not encouraged as it can lead to race
+ * conditions with userspace. For backward compatibility, "ring" sysfs could not be removed
+ * or decoupled from uio_hv_generic probe. Userspace programs can make use of inotify
+ * APIs to make sure that ring is created.
+ */
+ hv_create_ring_sysfs(channel, hv_uio_ring_mmap);
hv_set_drvdata(dev, pdata);
@@ -375,7 +370,7 @@ hv_uio_remove(struct hv_device *dev)
if (!pdata)
return;
- sysfs_remove_bin_file(&dev->channel->kobj, &ring_buffer_bin_attr);
+ hv_remove_ring_sysfs(dev->channel);
uio_unregister_device(&pdata->info);
hv_uio_cleanup(dev, pdata);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 675959fb97ba..d6ffe01962c2 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1002,6 +1002,12 @@ struct vmbus_channel {
/* The max size of a packet on this channel */
u32 max_pkt_size;
+
+ /* function to mmap ring buffer memory to the channel's sysfs ring attribute */
+ int (*mmap_ring_buffer)(struct vmbus_channel *channel, struct vm_area_struct *vma);
+
+ /* boolean to control visibility of sysfs for ring buffer */
+ bool ring_sysfs_visible;
};
#define lock_requestor(channel, flags) \
From: Wayne Lin <wayne.lin(a)amd.com>
[ Upstream commit fcf6a49d79923a234844b8efe830a61f3f0584e4 ]
[Why]
When unplug one of monitors connected after mst hub, encounter null pointer dereference.
It's due to dc_sink get released immediately in early_unregister() or detect_ctx(). When
commit new state which directly referring to info stored in dc_sink will cause null pointer
dereference.
[how]
Remove redundant checking condition. Relevant condition should already be covered by checking
if dsc_aux is null or not. Also reset dsc_aux to NULL when the connector is disconnected.
Reviewed-by: Jerry Zuo <jerry.zuo(a)amd.com>
Acked-by: Zaeem Mohamed <zaeem.mohamed(a)amd.com>
Signed-off-by: Wayne Lin <wayne.lin(a)amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
[The deleted codes in this fix is introduced by commit b9b5a82c5321
("drm/amd/display: Fix DSC-re-computing") after 6.11.]
Signed-off-by: Jianqi Ren <jianqi.ren.cn(a)windriver.com>
Signed-off-by: He Zhe <zhe.he(a)windriver.com>
---
Verified the build test
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 5eb994ed5471..6bb590bc7c19 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -183,6 +183,8 @@ amdgpu_dm_mst_connector_early_unregister(struct drm_connector *connector)
dc_sink_release(dc_sink);
aconnector->dc_sink = NULL;
aconnector->edid = NULL;
+ aconnector->dsc_aux = NULL;
+ port->passthrough_aux = NULL;
}
aconnector->mst_status = MST_STATUS_DEFAULT;
@@ -487,6 +489,8 @@ dm_dp_mst_detect(struct drm_connector *connector,
dc_sink_release(aconnector->dc_sink);
aconnector->dc_sink = NULL;
aconnector->edid = NULL;
+ aconnector->dsc_aux = NULL;
+ port->passthrough_aux = NULL;
amdgpu_dm_set_mst_status(&aconnector->mst_status,
MST_REMOTE_EDID | MST_ALLOCATE_NEW_PAYLOAD | MST_CLEAR_ALLOCATED_PAYLOAD,
--
2.34.1