Messages in this thread Patch in this message | | | Date | Mon, 23 Mar 2015 05:20:19 -0700 | From | tip-bot for Andy Lutomirski <> | Subject | [tip:x86/asm] x86/asm/entry, perf: Fix incorrect TIF_IA32 check in code_segment_base() |
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Commit-ID: c56716af8d27ca8dd6e45445ae1c0a05fd9753a6 Gitweb: http://git.kernel.org/tip/c56716af8d27ca8dd6e45445ae1c0a05fd9753a6 Author: Andy Lutomirski <luto@kernel.org> AuthorDate: Wed, 18 Mar 2015 18:33:28 -0700 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 23 Mar 2015 10:08:21 +0100
x86/asm/entry, perf: Fix incorrect TIF_IA32 check in code_segment_base()
We want to check whether user code is in 32-bit mode, not whether the task is nominally 32-bit.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brad Spengler <spender@grsecurity.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/33e5107085ce347a8303560302b15c2cadd62c4c.1426728647.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/cpu/perf_event.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index b71a7f8..979963b 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -2161,10 +2161,9 @@ static unsigned long code_segment_base(struct pt_regs *regs) if (user_mode(regs) && regs->cs != __USER_CS) return get_segment_base(regs->cs); #else - if (test_thread_flag(TIF_IA32)) { - if (user_mode(regs) && regs->cs != __USER32_CS) - return get_segment_base(regs->cs); - } + if (user_mode(regs) && !user_64bit_mode(regs) && + regs->cs != __USER32_CS) + return get_segment_base(regs->cs); #endif return 0; }
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