This is a note to let you know that I've just added the patch titled
MIPS: Implement __multi3 for GCC7 MIPS64r6 builds
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum…
The filename of the patch is:
mips-implement-__multi3-for-gcc7-mips64r6-builds.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable(a)vger.kernel.org> know about it.
>From ebabcf17bcd7ce968b1631ebe08236275698f39b Mon Sep 17 00:00:00 2001
From: James Hogan <jhogan(a)kernel.org>
Date: Thu, 7 Dec 2017 07:20:46 +0000
Subject: MIPS: Implement __multi3 for GCC7 MIPS64r6 builds
From: James Hogan <jhogan(a)kernel.org>
commit ebabcf17bcd7ce968b1631ebe08236275698f39b upstream.
GCC7 is a bit too eager to generate suboptimal __multi3 calls (128bit
multiply with 128bit result) for MIPS64r6 builds, even in code which
doesn't explicitly use 128bit types, such as the following:
unsigned long func(unsigned long a, unsigned long b)
{
return a > (~0UL) / b;
}
Which GCC rearanges to:
return (unsigned __int128)a * (unsigned __int128)b > 0xffffffffffffffff;
Therefore implement __multi3, but only for MIPS64r6 with GCC7 as under
normal circumstances we wouldn't expect any calls to __multi3 to be
generated from kernel code.
Reported-by: Thomas Petazzoni <thomas.petazzoni(a)free-electrons.com>
Signed-off-by: James Hogan <jhogan(a)kernel.org>
Tested-by: Waldemar Brodkorb <wbx(a)openadk.org>
Cc: Ralf Baechle <ralf(a)linux-mips.org>
Cc: Maciej W. Rozycki <macro(a)mips.com>
Cc: Matthew Fortune <matthew.fortune(a)mips.com>
Cc: Florian Fainelli <florian(a)openwrt.org>
Cc: linux-mips(a)linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17890/
Cc: Guenter Roeck <linux(a)roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
---
arch/mips/lib/Makefile | 3 +-
arch/mips/lib/libgcc.h | 17 +++++++++++++++
arch/mips/lib/multi3.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+), 1 deletion(-)
--- a/arch/mips/lib/Makefile
+++ b/arch/mips/lib/Makefile
@@ -16,4 +16,5 @@ obj-$(CONFIG_CPU_R3000) += r3k_dump_tlb
obj-$(CONFIG_CPU_TX39XX) += r3k_dump_tlb.o
# libgcc-style stuff needed in the kernel
-obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o ucmpdi2.o
+obj-y += ashldi3.o ashrdi3.o bswapsi.o bswapdi.o cmpdi2.o lshrdi3.o multi3.o \
+ ucmpdi2.o
--- a/arch/mips/lib/libgcc.h
+++ b/arch/mips/lib/libgcc.h
@@ -10,10 +10,18 @@ typedef int word_type __attribute__ ((mo
struct DWstruct {
int high, low;
};
+
+struct TWstruct {
+ long long high, low;
+};
#elif defined(__LITTLE_ENDIAN)
struct DWstruct {
int low, high;
};
+
+struct TWstruct {
+ long long low, high;
+};
#else
#error I feel sick.
#endif
@@ -23,4 +31,13 @@ typedef union {
long long ll;
} DWunion;
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6)
+typedef int ti_type __attribute__((mode(TI)));
+
+typedef union {
+ struct TWstruct s;
+ ti_type ti;
+} TWunion;
+#endif
+
#endif /* __ASM_LIBGCC_H */
--- /dev/null
+++ b/arch/mips/lib/multi3.c
@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/export.h>
+
+#include "libgcc.h"
+
+/*
+ * GCC 7 suboptimally generates __multi3 calls for mips64r6, so for that
+ * specific case only we'll implement it here.
+ *
+ * See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82981
+ */
+#if defined(CONFIG_64BIT) && defined(CONFIG_CPU_MIPSR6) && (__GNUC__ == 7)
+
+/* multiply 64-bit values, low 64-bits returned */
+static inline long long notrace dmulu(long long a, long long b)
+{
+ long long res;
+
+ asm ("dmulu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+ return res;
+}
+
+/* multiply 64-bit unsigned values, high 64-bits of 128-bit result returned */
+static inline long long notrace dmuhu(long long a, long long b)
+{
+ long long res;
+
+ asm ("dmuhu %0,%1,%2" : "=r" (res) : "r" (a), "r" (b));
+ return res;
+}
+
+/* multiply 128-bit values, low 128-bits returned */
+ti_type notrace __multi3(ti_type a, ti_type b)
+{
+ TWunion res, aa, bb;
+
+ aa.ti = a;
+ bb.ti = b;
+
+ /*
+ * a * b = (a.lo * b.lo)
+ * + 2^64 * (a.hi * b.lo + a.lo * b.hi)
+ * [+ 2^128 * (a.hi * b.hi)]
+ */
+ res.s.low = dmulu(aa.s.low, bb.s.low);
+ res.s.high = dmuhu(aa.s.low, bb.s.low);
+ res.s.high += dmulu(aa.s.high, bb.s.low);
+ res.s.high += dmulu(aa.s.low, bb.s.high);
+
+ return res.ti;
+}
+EXPORT_SYMBOL(__multi3);
+
+#endif /* 64BIT && CPU_MIPSR6 && GCC7 */
Patches currently in stable-queue which might be from jhogan(a)kernel.org are
queue-4.14/lib-mpi-fix-umul_ppmm-for-mips64r6.patch
queue-4.14/mips-implement-__multi3-for-gcc7-mips64r6-builds.patch
Hi Greg,
please apply commit ebabcf17bcd7 ("MIPS: Implement __multi3 for GCC7 MIPS64r6 builds")
to linux-4.4.y .. linux-4.14.y to fix the following build problem, seen when building
mipsr6 images with gcc 7.3.0.
crypto/scompress.o: In function `kmalloc_array':
include/linux/slab.h:603: undefined reference to `__multi3'
Thanks,
Guenter
On Mon, Feb 26, 2018 at 4:22 AM, Jerry Hoemann <jerry.hoemann(a)hpe.com> wrote:
> Gen8 and prior Proliant systems supported the "CRU" interface
> to firmware. This interfaces allows linux to "call back" into firmware
> to source the cause of an NMI. This feature isn't fully utilized
> as the actual source of the NMI isn't printed, the driver only
> indicates that the source couldn't be determined when the call
> fails.
>
> With the advent of Gen9, iCRU replaces the CRU. The call back
> feature is no longer available in firmware. To be compatible and
> not attempt to call back into firmware on system not supporting CRU,
> the SMBIOS table is consulted to determine if it is safe to
> make the call back or not.
>
> This results in about half of the driver code being devoted
> to either making CRU calls or determing if it is safe to make
> CRU calls. As noted, the driver isn't really using the results of
> the CRU calls.
>
> Furthermore, as a consequence of the Spectre security issue, the
> BIOS/EFI calls are being wrapped into Spectre-disabling section.
> Removing the call back in hpwdt_pretimeout assists in this effort.
>
> As the CRU sourcing of the NMI isn't required for handling the
> NMI and there are security concerns with making the call back, remove
> the legacy (pre Gen9) NMI sourcing and the DMI code to determine if
> the system had the CRU interface.
>
> Signed-off-by: Jerry Hoemann <jerry.hoemann(a)hpe.com>
This avoids a warning in mainline kernels, so that's great:
drivers/watchdog/hpwdt.o: warning: objtool: .text+0x24: indirect call
found in RETPOLINE build
I wonder what we do about stable kernels. Are both this patch and the patch
that added the objtool warning message candidates for backports to
stable kernels?
Arnd
From: Leif Liddy <leif.linux(a)gmail.com>
This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.
===============
[ Upstream commit fd865802c66bc451dc515ed89360f84376ce1a56 ]
There's been numerous reported instances where BTUSB_QCA_ROME
bluetooth controllers stop functioning upon resume from suspend. These
devices seem to be losing power during suspend. Patch will detect a status
change on resume and perform a reset.
Signed-off-by: Leif Liddy <leif.linux(a)gmail.com>
Signed-off-by: Marcel Holtmann <marcel(a)holtmann.org>
Signed-off-by: Sasha Levin <alexander.levin(a)microsoft.com>
---
drivers/bluetooth/btusb.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 32f5b87fe93c..b17bd3fc74cb 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3207,6 +3207,12 @@ static int btusb_probe(struct usb_interface *intf,
if (id->driver_info & BTUSB_QCA_ROME) {
data->setup_on_usb = btusb_setup_qca;
hdev->set_bdaddr = btusb_set_bdaddr_ath3012;
+
+ /* QCA Rome devices lose their updated firmware over suspend,
+ * but the USB hub doesn't notice any status change.
+ * Explicitly request a device reset on resume.
+ */
+ set_bit(BTUSB_RESET_RESUME, &data->flags);
}
if (id->driver_info & BTUSB_REALTEK)
--
2.14.1
The patch titled
Subject: lib/bug.c: exclude non-BUG/WARN exceptions from report_bug()
has been added to the -mm tree. Its filename is
bug-exclude-non-bug-warn-exceptions-from-report_bug.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/bug-exclude-non-bug-warn-exception…
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/bug-exclude-non-bug-warn-exception…
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/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook(a)chromium.org>
Subject: lib/bug.c: exclude non-BUG/WARN exceptions from report_bug()
b8347c219649 ("x86/debug: Handle warnings before the notifier chain, to
fix KGDB crash") changed the ordering of fixups, and did not take into
account the case of x86 processing non-WARN() and non-BUG() exceptions.
This would lead to output of a false BUG line with no other information.
In the case of a refcount exception, it would be immediately followed by
the refcount WARN(), producing very strange double-"cut here":
lkdtm: attempting bad refcount_inc() overflow
------------[ cut here ]------------
Kernel BUG at 0000000065f29de5 [verbose debug info unavailable]
------------[ cut here ]------------
refcount_t overflow at lkdtm_REFCOUNT_INC_OVERFLOW+0x6b/0x90 in cat[3065], uid/euid: 0/0
WARNING: CPU: 0 PID: 3065 at kernel/panic.c:657 refcount_error_report+0x9a/0xa4
...
In the prior ordering, exceptions were searched first:
do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
...
if (fixup_exception(regs, trapnr))
return 0;
- if (fixup_bug(regs, trapnr))
- return 0;
-
As a result, fixup_bugs()'s is_valid_bugaddr() didn't take into account
needing to search the exception list first, since that had already
happened.
So, instead of searching the exception list twice (once in
is_valid_bugaddr() and then again in fixup_exception()), just add a simple
sanity check to report_bug() that will immediately bail out if a BUG() (or
WARN()) entry is not found.
Link: http://lkml.kernel.org/r/20180301225934.GA34350@beast
Fixes: b8347c219649 ("x86/debug: Handle warnings before the notifier chain, to fix KGDB crash")
Signed-off-by: Kees Cook <keescook(a)chromium.org>
Cc: Ingo Molnar <mingo(a)kernel.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: Richard Weinberger <richard.weinberger(a)gmail.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
lib/bug.c | 2 ++
1 file changed, 2 insertions(+)
diff -puN lib/bug.c~bug-exclude-non-bug-warn-exceptions-from-report_bug lib/bug.c
--- a/lib/bug.c~bug-exclude-non-bug-warn-exceptions-from-report_bug
+++ a/lib/bug.c
@@ -150,6 +150,8 @@ enum bug_trap_type report_bug(unsigned l
return BUG_TRAP_TYPE_NONE;
bug = find_bug(bugaddr);
+ if (!bug)
+ return BUG_TRAP_TYPE_NONE;
file = NULL;
line = 0;
_
Patches currently in -mm which might be from keescook(a)chromium.org are
bug-use-%pb-in-bug-and-stack-protector-failure.patch
bug-exclude-non-bug-warn-exceptions-from-report_bug.patch
taint-convert-to-indexed-initialization.patch
taint-consolidate-documentation.patch
taint-add-taint-for-randstruct.patch
fork-unconditionally-clear-stack-on-fork.patch
exec-pass-stack-rlimit-into-mm-layout-functions.patch
exec-introduce-finalize_exec-before-start_thread.patch
exec-pin-stack-limit-during-exec.patch
The patch titled
Subject: bug: use %pB in BUG and stack protector failure
has been added to the -mm tree. Its filename is
bug-use-%pb-in-bug-and-stack-protector-failure.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/bug-use-%25pb-in-bug-and-stack-pro…
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/bug-use-%25pb-in-bug-and-stack-pro…
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/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook(a)chromium.org>
Subject: bug: use %pB in BUG and stack protector failure
The BUG and stack protector reports were still using a raw %p. This
changes it to %pB for more meaningful output.
Link: http://lkml.kernel.org/r/20180301225704.GA34198@beast
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Signed-off-by: Kees Cook <keescook(a)chromium.org>
Reviewed-by: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Ingo Molnar <mingo(a)kernel.org>
Cc: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: Borislav Petkov <bp(a)alien8.de>
Cc: Richard Weinberger <richard.weinberger(a)gmail.com>,
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
kernel/panic.c | 2 +-
lib/bug.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff -puN kernel/panic.c~bug-use-%pb-in-bug-and-stack-protector-failure kernel/panic.c
--- a/kernel/panic.c~bug-use-%pb-in-bug-and-stack-protector-failure
+++ a/kernel/panic.c
@@ -629,7 +629,7 @@ device_initcall(register_warn_debugfs);
*/
__visible void __stack_chk_fail(void)
{
- panic("stack-protector: Kernel stack is corrupted in: %p\n",
+ panic("stack-protector: Kernel stack is corrupted in: %pB\n",
__builtin_return_address(0));
}
EXPORT_SYMBOL(__stack_chk_fail);
diff -puN lib/bug.c~bug-use-%pb-in-bug-and-stack-protector-failure lib/bug.c
--- a/lib/bug.c~bug-use-%pb-in-bug-and-stack-protector-failure
+++ a/lib/bug.c
@@ -191,7 +191,7 @@ enum bug_trap_type report_bug(unsigned l
if (file)
pr_crit("kernel BUG at %s:%u!\n", file, line);
else
- pr_crit("Kernel BUG at %p [verbose debug info unavailable]\n",
+ pr_crit("Kernel BUG at %pB [verbose debug info unavailable]\n",
(void *)bugaddr);
return BUG_TRAP_TYPE_BUG;
_
Patches currently in -mm which might be from keescook(a)chromium.org are
bug-use-%pb-in-bug-and-stack-protector-failure.patch
taint-convert-to-indexed-initialization.patch
taint-consolidate-documentation.patch
taint-add-taint-for-randstruct.patch
fork-unconditionally-clear-stack-on-fork.patch
exec-pass-stack-rlimit-into-mm-layout-functions.patch
exec-introduce-finalize_exec-before-start_thread.patch
exec-pin-stack-limit-during-exec.patch