A xHC USB 3 port might miss the first wake signal from a USB 3 device
if the port LFPS reveiver isn't enabled fast enough after xHC resume.
xHC host will anyway be resumed by a PME# signal, but will go back to
suspend if no port activity is seen.
The device resends the U3 LFPS wake signal after a 100ms delay, but
by then host is already suspended, starting all over from the
beginning of this issue.
USB 3 specs say U3 wake LFPS signal is sent for max 10ms, then device
needs to delay 100ms before resending the wake.
Don't suspend immediately if port activity isn't detected in resume.
Instead add a retry. If there is no port activity then delay for 120ms,
and re-check for port activity.
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com>
---
drivers/usb/host/xhci.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index bd27bd670104..48a68fcf2b36 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1088,6 +1088,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
struct usb_hcd *secondary_hcd;
int retval = 0;
bool comp_timer_running = false;
+ bool pending_portevent = false;
if (!hcd->state)
return 0;
@@ -1226,13 +1227,22 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
done:
if (retval == 0) {
- /* Resume root hubs only when have pending events. */
- if (xhci_pending_portevent(xhci)) {
+ /*
+ * Resume roothubs only if there are pending events.
+ * USB 3 devices resend U3 LFPS wake after a 100ms delay if
+ * the first wake signalling failed, give it that chance.
+ */
+ pending_portevent = xhci_pending_portevent(xhci);
+ if (!pending_portevent) {
+ msleep(120);
+ pending_portevent = xhci_pending_portevent(xhci);
+ }
+
+ if (pending_portevent) {
usb_hcd_resume_root_hub(xhci->shared_hcd);
usb_hcd_resume_root_hub(hcd);
}
}
-
/*
* If system is subject to the Quirk, Compliance Mode Timer needs to
* be re-initialized Always after a system resume. Ports are subject
--
2.25.1
The GIC driver uses a RMW sequence to update the affinity, and
relies on the gic_lock_irqsave/gic_unlock_irqrestore sequences
to update it atomically.
But these sequences only expend into anything meaningful if
the BL_SWITCHER option is selected, which almost never happens.
It also turns out that using a RMW and locks is just as silly,
as the GIC distributor supports byte accesses for the GICD_TARGETRn
registers, which when used make the update atomic by definition.
Drop the terminally broken code and replace it by a byte write.
Fixes: 04c8b0f82c7d ("irqchip/gic: Make locking a BL_SWITCHER only feature")
Cc: stable(a)vger.kernel.org
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
---
drivers/irqchip/irq-gic.c | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 00de05abd3c3..c17fabd6741e 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -329,10 +329,8 @@ static int gic_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
bool force)
{
- void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + (gic_irq(d) & ~3);
- unsigned int cpu, shift = (gic_irq(d) % 4) * 8;
- u32 val, mask, bit;
- unsigned long flags;
+ void __iomem *reg = gic_dist_base(d) + GIC_DIST_TARGET + gic_irq(d);
+ unsigned int cpu;
if (!force)
cpu = cpumask_any_and(mask_val, cpu_online_mask);
@@ -342,13 +340,7 @@ static int gic_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
if (cpu >= NR_GIC_CPU_IF || cpu >= nr_cpu_ids)
return -EINVAL;
- gic_lock_irqsave(flags);
- mask = 0xff << shift;
- bit = gic_cpu_map[cpu] << shift;
- val = readl_relaxed(reg) & ~mask;
- writel_relaxed(val | bit, reg);
- gic_unlock_irqrestore(flags);
-
+ writeb_relaxed(gic_cpu_map[cpu], reg);
irq_data_update_effective_affinity(d, cpumask_of(cpu));
return IRQ_SET_MASK_OK_DONE;
--
2.27.0
The ASMedia ASM1062 SATA controller causes an External Abort on
controllers which support Max Payload Size >= 512. It happens with
Aardvark PCIe controller (tested on Turris MOX) and also with DesignWare
controller (armada8k, tested on CN9130-CRB):
ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
ata1.00: ATA-9: WDC WD40EFRX-68WT0N0, 80.00A80, max UDMA/133
ata1.00: 7814037168 sectors, multi 0: LBA48 NCQ (depth 32), AA
ERROR: Unhandled External Abort received on 0x80000000 at EL3!
ERROR: exception reason=1 syndrome=0x92000210
PANIC at PC : 0x00000000040273bc
Limiting Max Payload Size to 256 bytes solves this problem.
On Turris MOX this problem first appeared when the pci-aardvark
controller started using the pci-emul-bridge API, in commit 8a3ebd8de328
("PCI: aardvark: Implement emulated root PCI bridge config space").
On armada8k this was always a problem because it has HW root bridge.
Signed-off-by: Marek Behún <kabel(a)kernel.org>
Reported-by: Rötti <espressobinboardarmbiantempmailaddress(a)posteo.de>
Cc: Pali Rohár <pali(a)kernel.org>
Cc: stable(a)vger.kernel.org
---
drivers/pci/quirks.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 653660e3ba9e..a561136efb08 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3251,6 +3251,11 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SOLARFLARE,
PCI_DEVICE_ID_SOLARFLARE_SFC4000A_1, fixup_mpss_256);
DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SOLARFLARE,
PCI_DEVICE_ID_SOLARFLARE_SFC4000B, fixup_mpss_256);
+/*
+ * For some reason DECLARE_PCI_FIXUP_HEADER does not work with pci-aardvark
+ * controller. We have to use DECLARE_PCI_FIXUP_EARLY.
+ */
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ASMEDIA, 0x0612, fixup_mpss_256);
/*
* Intel 5000 and 5100 Memory controllers have an erratum with read completion
--
2.26.2
The patch below does not apply to the 5.4-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f9dfb5e390fab2df9f7944bb91e7705aba14cd26 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx(a)linutronix.de>
Date: Fri, 18 Jun 2021 16:18:25 +0200
Subject: [PATCH] x86/fpu: Make init_fpstate correct with optimized XSAVE
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.
This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.
There are two ways to solve that:
1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
XSAVES is enabled because XSAVES uses compacted format.
2) Save the components which are known to have a non-zero init state by other
means.
Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.
Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.
The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.
[ bp: Fix a typo or two in the text. ]
Fixes: 6bad06b76892 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Borislav Petkov <bp(a)suse.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index fdee23ea4e17..16bf4d4a8159 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -204,6 +204,14 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
}
+static inline void fxsave(struct fxregs_state *fx)
+{
+ if (IS_ENABLED(CONFIG_X86_32))
+ asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx));
+ else
+ asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx));
+}
+
/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
@@ -268,28 +276,6 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
-/*
- * This function is called only during boot time when x86 caps are not set
- * up and alternative can not be used yet.
- */
-static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate)
-{
- u64 mask = xfeatures_mask_all;
- u32 lmask = mask;
- u32 hmask = mask >> 32;
- int err;
-
- WARN_ON(system_state != SYSTEM_BOOTING);
-
- if (boot_cpu_has(X86_FEATURE_XSAVES))
- XSTATE_OP(XSAVES, xstate, lmask, hmask, err);
- else
- XSTATE_OP(XSAVE, xstate, lmask, hmask, err);
-
- /* We should never fault when copying to a kernel buffer: */
- WARN_ON_FPU(err);
-}
-
/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index d0eef963aad1..1cadb2faf740 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -440,6 +440,25 @@ static void __init print_xstate_offset_size(void)
}
}
+/*
+ * All supported features have either init state all zeros or are
+ * handled in setup_init_fpu() individually. This is an explicit
+ * feature list and does not use XFEATURE_MASK*SUPPORTED to catch
+ * newly added supported features at build time and make people
+ * actually look at the init state for the new feature.
+ */
+#define XFEATURES_INIT_FPSTATE_HANDLED \
+ (XFEATURE_MASK_FP | \
+ XFEATURE_MASK_SSE | \
+ XFEATURE_MASK_YMM | \
+ XFEATURE_MASK_OPMASK | \
+ XFEATURE_MASK_ZMM_Hi256 | \
+ XFEATURE_MASK_Hi16_ZMM | \
+ XFEATURE_MASK_PKRU | \
+ XFEATURE_MASK_BNDREGS | \
+ XFEATURE_MASK_BNDCSR | \
+ XFEATURE_MASK_PASID)
+
/*
* setup the xstate image representing the init state
*/
@@ -447,6 +466,10 @@ static void __init setup_init_fpu_buf(void)
{
static int on_boot_cpu __initdata = 1;
+ BUILD_BUG_ON((XFEATURE_MASK_USER_SUPPORTED |
+ XFEATURE_MASK_SUPERVISOR_SUPPORTED) !=
+ XFEATURES_INIT_FPSTATE_HANDLED);
+
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;
@@ -466,10 +489,22 @@ static void __init setup_init_fpu_buf(void)
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
/*
- * Dump the init state again. This is to identify the init state
- * of any feature which is not represented by all zero's.
+ * All components are now in init state. Read the state back so
+ * that init_fpstate contains all non-zero init state. This only
+ * works with XSAVE, but not with XSAVEOPT and XSAVES because
+ * those use the init optimization which skips writing data for
+ * components in init state.
+ *
+ * XSAVE could be used, but that would require to reshuffle the
+ * data when XSAVES is available because XSAVES uses xstate
+ * compaction. But doing so is a pointless exercise because most
+ * components have an all zeros init state except for the legacy
+ * ones (FP and SSE). Those can be saved with FXSAVE into the
+ * legacy area. Adding new features requires to ensure that init
+ * state is all zeroes or if not to add the necessary handling
+ * here.
*/
- copy_xregs_to_kernel_booting(&init_fpstate.xsave);
+ fxsave(&init_fpstate.fxsave);
}
static int xfeature_uncompacted_offset(int xfeature_nr)
The patch below does not apply to the 4.19-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f9dfb5e390fab2df9f7944bb91e7705aba14cd26 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx(a)linutronix.de>
Date: Fri, 18 Jun 2021 16:18:25 +0200
Subject: [PATCH] x86/fpu: Make init_fpstate correct with optimized XSAVE
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.
This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.
There are two ways to solve that:
1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
XSAVES is enabled because XSAVES uses compacted format.
2) Save the components which are known to have a non-zero init state by other
means.
Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.
Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.
The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.
[ bp: Fix a typo or two in the text. ]
Fixes: 6bad06b76892 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Borislav Petkov <bp(a)suse.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index fdee23ea4e17..16bf4d4a8159 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -204,6 +204,14 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
}
+static inline void fxsave(struct fxregs_state *fx)
+{
+ if (IS_ENABLED(CONFIG_X86_32))
+ asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx));
+ else
+ asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx));
+}
+
/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
@@ -268,28 +276,6 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
-/*
- * This function is called only during boot time when x86 caps are not set
- * up and alternative can not be used yet.
- */
-static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate)
-{
- u64 mask = xfeatures_mask_all;
- u32 lmask = mask;
- u32 hmask = mask >> 32;
- int err;
-
- WARN_ON(system_state != SYSTEM_BOOTING);
-
- if (boot_cpu_has(X86_FEATURE_XSAVES))
- XSTATE_OP(XSAVES, xstate, lmask, hmask, err);
- else
- XSTATE_OP(XSAVE, xstate, lmask, hmask, err);
-
- /* We should never fault when copying to a kernel buffer: */
- WARN_ON_FPU(err);
-}
-
/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index d0eef963aad1..1cadb2faf740 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -440,6 +440,25 @@ static void __init print_xstate_offset_size(void)
}
}
+/*
+ * All supported features have either init state all zeros or are
+ * handled in setup_init_fpu() individually. This is an explicit
+ * feature list and does not use XFEATURE_MASK*SUPPORTED to catch
+ * newly added supported features at build time and make people
+ * actually look at the init state for the new feature.
+ */
+#define XFEATURES_INIT_FPSTATE_HANDLED \
+ (XFEATURE_MASK_FP | \
+ XFEATURE_MASK_SSE | \
+ XFEATURE_MASK_YMM | \
+ XFEATURE_MASK_OPMASK | \
+ XFEATURE_MASK_ZMM_Hi256 | \
+ XFEATURE_MASK_Hi16_ZMM | \
+ XFEATURE_MASK_PKRU | \
+ XFEATURE_MASK_BNDREGS | \
+ XFEATURE_MASK_BNDCSR | \
+ XFEATURE_MASK_PASID)
+
/*
* setup the xstate image representing the init state
*/
@@ -447,6 +466,10 @@ static void __init setup_init_fpu_buf(void)
{
static int on_boot_cpu __initdata = 1;
+ BUILD_BUG_ON((XFEATURE_MASK_USER_SUPPORTED |
+ XFEATURE_MASK_SUPERVISOR_SUPPORTED) !=
+ XFEATURES_INIT_FPSTATE_HANDLED);
+
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;
@@ -466,10 +489,22 @@ static void __init setup_init_fpu_buf(void)
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
/*
- * Dump the init state again. This is to identify the init state
- * of any feature which is not represented by all zero's.
+ * All components are now in init state. Read the state back so
+ * that init_fpstate contains all non-zero init state. This only
+ * works with XSAVE, but not with XSAVEOPT and XSAVES because
+ * those use the init optimization which skips writing data for
+ * components in init state.
+ *
+ * XSAVE could be used, but that would require to reshuffle the
+ * data when XSAVES is available because XSAVES uses xstate
+ * compaction. But doing so is a pointless exercise because most
+ * components have an all zeros init state except for the legacy
+ * ones (FP and SSE). Those can be saved with FXSAVE into the
+ * legacy area. Adding new features requires to ensure that init
+ * state is all zeroes or if not to add the necessary handling
+ * here.
*/
- copy_xregs_to_kernel_booting(&init_fpstate.xsave);
+ fxsave(&init_fpstate.fxsave);
}
static int xfeature_uncompacted_offset(int xfeature_nr)
The patch below does not apply to the 4.14-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f9dfb5e390fab2df9f7944bb91e7705aba14cd26 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx(a)linutronix.de>
Date: Fri, 18 Jun 2021 16:18:25 +0200
Subject: [PATCH] x86/fpu: Make init_fpstate correct with optimized XSAVE
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.
This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.
There are two ways to solve that:
1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
XSAVES is enabled because XSAVES uses compacted format.
2) Save the components which are known to have a non-zero init state by other
means.
Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.
Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.
The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.
[ bp: Fix a typo or two in the text. ]
Fixes: 6bad06b76892 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Borislav Petkov <bp(a)suse.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index fdee23ea4e17..16bf4d4a8159 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -204,6 +204,14 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
}
+static inline void fxsave(struct fxregs_state *fx)
+{
+ if (IS_ENABLED(CONFIG_X86_32))
+ asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx));
+ else
+ asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx));
+}
+
/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
@@ -268,28 +276,6 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
-/*
- * This function is called only during boot time when x86 caps are not set
- * up and alternative can not be used yet.
- */
-static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate)
-{
- u64 mask = xfeatures_mask_all;
- u32 lmask = mask;
- u32 hmask = mask >> 32;
- int err;
-
- WARN_ON(system_state != SYSTEM_BOOTING);
-
- if (boot_cpu_has(X86_FEATURE_XSAVES))
- XSTATE_OP(XSAVES, xstate, lmask, hmask, err);
- else
- XSTATE_OP(XSAVE, xstate, lmask, hmask, err);
-
- /* We should never fault when copying to a kernel buffer: */
- WARN_ON_FPU(err);
-}
-
/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index d0eef963aad1..1cadb2faf740 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -440,6 +440,25 @@ static void __init print_xstate_offset_size(void)
}
}
+/*
+ * All supported features have either init state all zeros or are
+ * handled in setup_init_fpu() individually. This is an explicit
+ * feature list and does not use XFEATURE_MASK*SUPPORTED to catch
+ * newly added supported features at build time and make people
+ * actually look at the init state for the new feature.
+ */
+#define XFEATURES_INIT_FPSTATE_HANDLED \
+ (XFEATURE_MASK_FP | \
+ XFEATURE_MASK_SSE | \
+ XFEATURE_MASK_YMM | \
+ XFEATURE_MASK_OPMASK | \
+ XFEATURE_MASK_ZMM_Hi256 | \
+ XFEATURE_MASK_Hi16_ZMM | \
+ XFEATURE_MASK_PKRU | \
+ XFEATURE_MASK_BNDREGS | \
+ XFEATURE_MASK_BNDCSR | \
+ XFEATURE_MASK_PASID)
+
/*
* setup the xstate image representing the init state
*/
@@ -447,6 +466,10 @@ static void __init setup_init_fpu_buf(void)
{
static int on_boot_cpu __initdata = 1;
+ BUILD_BUG_ON((XFEATURE_MASK_USER_SUPPORTED |
+ XFEATURE_MASK_SUPERVISOR_SUPPORTED) !=
+ XFEATURES_INIT_FPSTATE_HANDLED);
+
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;
@@ -466,10 +489,22 @@ static void __init setup_init_fpu_buf(void)
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
/*
- * Dump the init state again. This is to identify the init state
- * of any feature which is not represented by all zero's.
+ * All components are now in init state. Read the state back so
+ * that init_fpstate contains all non-zero init state. This only
+ * works with XSAVE, but not with XSAVEOPT and XSAVES because
+ * those use the init optimization which skips writing data for
+ * components in init state.
+ *
+ * XSAVE could be used, but that would require to reshuffle the
+ * data when XSAVES is available because XSAVES uses xstate
+ * compaction. But doing so is a pointless exercise because most
+ * components have an all zeros init state except for the legacy
+ * ones (FP and SSE). Those can be saved with FXSAVE into the
+ * legacy area. Adding new features requires to ensure that init
+ * state is all zeroes or if not to add the necessary handling
+ * here.
*/
- copy_xregs_to_kernel_booting(&init_fpstate.xsave);
+ fxsave(&init_fpstate.fxsave);
}
static int xfeature_uncompacted_offset(int xfeature_nr)
The patch below does not apply to the 4.9-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>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From f9dfb5e390fab2df9f7944bb91e7705aba14cd26 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx(a)linutronix.de>
Date: Fri, 18 Jun 2021 16:18:25 +0200
Subject: [PATCH] x86/fpu: Make init_fpstate correct with optimized XSAVE
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.
This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.
There are two ways to solve that:
1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
XSAVES is enabled because XSAVES uses compacted format.
2) Save the components which are known to have a non-zero init state by other
means.
Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.
Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.
The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.
[ bp: Fix a typo or two in the text. ]
Fixes: 6bad06b76892 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Borislav Petkov <bp(a)suse.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index fdee23ea4e17..16bf4d4a8159 100644
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -204,6 +204,14 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
asm volatile("fxsaveq %[fx]" : [fx] "=m" (fpu->state.fxsave));
}
+static inline void fxsave(struct fxregs_state *fx)
+{
+ if (IS_ENABLED(CONFIG_X86_32))
+ asm volatile( "fxsave %[fx]" : [fx] "=m" (*fx));
+ else
+ asm volatile("fxsaveq %[fx]" : [fx] "=m" (*fx));
+}
+
/* These macros all use (%edi)/(%rdi) as the single memory argument. */
#define XSAVE ".byte " REX_PREFIX "0x0f,0xae,0x27"
#define XSAVEOPT ".byte " REX_PREFIX "0x0f,0xae,0x37"
@@ -268,28 +276,6 @@ static inline void copy_fxregs_to_kernel(struct fpu *fpu)
: "D" (st), "m" (*st), "a" (lmask), "d" (hmask) \
: "memory")
-/*
- * This function is called only during boot time when x86 caps are not set
- * up and alternative can not be used yet.
- */
-static inline void copy_xregs_to_kernel_booting(struct xregs_state *xstate)
-{
- u64 mask = xfeatures_mask_all;
- u32 lmask = mask;
- u32 hmask = mask >> 32;
- int err;
-
- WARN_ON(system_state != SYSTEM_BOOTING);
-
- if (boot_cpu_has(X86_FEATURE_XSAVES))
- XSTATE_OP(XSAVES, xstate, lmask, hmask, err);
- else
- XSTATE_OP(XSAVE, xstate, lmask, hmask, err);
-
- /* We should never fault when copying to a kernel buffer: */
- WARN_ON_FPU(err);
-}
-
/*
* This function is called only during boot time when x86 caps are not set
* up and alternative can not be used yet.
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index d0eef963aad1..1cadb2faf740 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -440,6 +440,25 @@ static void __init print_xstate_offset_size(void)
}
}
+/*
+ * All supported features have either init state all zeros or are
+ * handled in setup_init_fpu() individually. This is an explicit
+ * feature list and does not use XFEATURE_MASK*SUPPORTED to catch
+ * newly added supported features at build time and make people
+ * actually look at the init state for the new feature.
+ */
+#define XFEATURES_INIT_FPSTATE_HANDLED \
+ (XFEATURE_MASK_FP | \
+ XFEATURE_MASK_SSE | \
+ XFEATURE_MASK_YMM | \
+ XFEATURE_MASK_OPMASK | \
+ XFEATURE_MASK_ZMM_Hi256 | \
+ XFEATURE_MASK_Hi16_ZMM | \
+ XFEATURE_MASK_PKRU | \
+ XFEATURE_MASK_BNDREGS | \
+ XFEATURE_MASK_BNDCSR | \
+ XFEATURE_MASK_PASID)
+
/*
* setup the xstate image representing the init state
*/
@@ -447,6 +466,10 @@ static void __init setup_init_fpu_buf(void)
{
static int on_boot_cpu __initdata = 1;
+ BUILD_BUG_ON((XFEATURE_MASK_USER_SUPPORTED |
+ XFEATURE_MASK_SUPERVISOR_SUPPORTED) !=
+ XFEATURES_INIT_FPSTATE_HANDLED);
+
WARN_ON_FPU(!on_boot_cpu);
on_boot_cpu = 0;
@@ -466,10 +489,22 @@ static void __init setup_init_fpu_buf(void)
copy_kernel_to_xregs_booting(&init_fpstate.xsave);
/*
- * Dump the init state again. This is to identify the init state
- * of any feature which is not represented by all zero's.
+ * All components are now in init state. Read the state back so
+ * that init_fpstate contains all non-zero init state. This only
+ * works with XSAVE, but not with XSAVEOPT and XSAVES because
+ * those use the init optimization which skips writing data for
+ * components in init state.
+ *
+ * XSAVE could be used, but that would require to reshuffle the
+ * data when XSAVES is available because XSAVES uses xstate
+ * compaction. But doing so is a pointless exercise because most
+ * components have an all zeros init state except for the legacy
+ * ones (FP and SSE). Those can be saved with FXSAVE into the
+ * legacy area. Adding new features requires to ensure that init
+ * state is all zeroes or if not to add the necessary handling
+ * here.
*/
- copy_xregs_to_kernel_booting(&init_fpstate.xsave);
+ fxsave(&init_fpstate.fxsave);
}
static int xfeature_uncompacted_offset(int xfeature_nr)