This is a note to let you know that I've just added the patch titled
x86/oprofile/ppro: Do not use __this_cpu*() in preemptible context
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-oprofile-ppro-do-not-use-__this_cpu-in-preemptible-context.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a743bbeef27b9176987ec0cb7f906ab0ab52d1da Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@xxxxxxx>
Date: Tue, 7 Nov 2017 18:53:07 +0100
Subject: x86/oprofile/ppro: Do not use __this_cpu*() in preemptible context
From: Borislav Petkov <bp@xxxxxxx>
commit a743bbeef27b9176987ec0cb7f906ab0ab52d1da upstream.
The warning below says it all:
BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1
caller is __this_cpu_preempt_check
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.14.0-rc8 #4
Call Trace:
dump_stack
check_preemption_disabled
? do_early_param
__this_cpu_preempt_check
arch_perfmon_init
op_nmi_init
? alloc_pci_root_info
oprofile_arch_init
oprofile_init
do_one_initcall
...
These accessors should not have been used in the first place: it is PPro so
no mixed silicon revisions and thus it can simply use boot_cpu_data.
Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Tested-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
Fix-creation-mandated-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Robert Richter <rric@xxxxxxxxxx>
Cc: x86@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/oprofile/op_model_ppro.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/oprofile/op_model_ppro.c
+++ b/arch/x86/oprofile/op_model_ppro.c
@@ -212,8 +212,8 @@ static void arch_perfmon_setup_counters(
eax.full = cpuid_eax(0xa);
/* Workaround for BIOS bugs in 6/15. Taken from perfmon2 */
- if (eax.split.version_id == 0 && __this_cpu_read(cpu_info.x86) == 6 &&
- __this_cpu_read(cpu_info.x86_model) == 15) {
+ if (eax.split.version_id == 0 && boot_cpu_data.x86 == 6 &&
+ boot_cpu_data.x86_model == 15) {
eax.split.version_id = 2;
eax.split.num_counters = 2;
eax.split.bit_width = 40;
Patches currently in stable-queue which might be from bp@xxxxxxx are
queue-4.4/x86-oprofile-ppro-do-not-use-__this_cpu-in-preemptible-context.patch