On Tue, Nov 07, 2017 at 06:53:07PM +0100, Borislav Petkov wrote:
On Tue, Nov 07, 2017 at 08:43:40AM -0800, Linus Torvalds wrote:
So I'm adding Borislav to the cc just to maybe annoy him into sending
in a patch for this thing too..
/me runs away like the wind!
This is the famous "you touched it last, tag you're it" model of
kernel maintainership.
Oh great, like I don't have enough crappy code to maintain already.
And besides, I'm sure Robert would've addressed it eventually, once he
moves his head up from Cavium-land. Oh well, it is simple enough, lemme
take care of it. :-)
Fengguang, please run it to confirm.
Yes it fixed the problem!
Tested-by: Fengguang Wu <fengguang...@intel.com>
Thanks,
Fengguang
Thx.
---
From: Borislav Petkov <b...@suse.de>
Subject: [PATCH] x86/oprofile/ppro: Do not use __this_cpu* accessors in
preemptible context
The warning below says it all. And we should not have used those
accessors in the first place: it is PPro so no mixed silicon revisions
and thus can simply use boot_cpu_data.
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
...
Reported-by: Fengguang Wu <fengguang...@intel.com>
Signed-off-by: Borislav Petkov <b...@suse.de>
Fix-creation-mandated-by: Linus Torvalds <torva...@linux-foundation.org>
Cc: Robert Richter <r...@kernel.org>
Cc: x...@kernel.org
---
arch/x86/oprofile/op_model_ppro.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/oprofile/op_model_ppro.c
b/arch/x86/oprofile/op_model_ppro.c
index 350f7096baac..1c3b400b05ce 100644
--- a/arch/x86/oprofile/op_model_ppro.c
+++ b/arch/x86/oprofile/op_model_ppro.c
@@ -212,8 +212,9 @@ static void arch_perfmon_setup_counters(void)
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;
--
2.13.0
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284
(AG Nürnberg)
--
