Commit c56716af authored Mar 18, 2015 by Andy Lutomirski Committed by Ingo Molnar Mar 23, 2015

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>

parent d31bf07f

arch/x86/kernel/cpu/perf_event.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -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)
		if (user_mode(regs) && !user_64bit_mode(regs) &&
		regs->cs != __USER32_CS)
		return get_segment_base(regs->cs);
		}
		#endif
		return 0;
		}