Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 33/33] x86/oprofile/ppro: Do not use __this_cpu*() in preemptible context | Date | Mon, 13 Nov 2017 13:56:54 +0100 |
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4.13-stable review patch. If anyone has any objections, please let me know.
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From: Borislav Petkov <bp@suse.de>
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@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Fix-creation-mandated-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Robert Richter <rric@kernel.org> Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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;
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