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author | Peter Zijlstra <peterz@infradead.org> | 2019-07-11 14:40:59 +0300 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-18 00:17:38 +0300 |
commit | a0d14b8909de55139b8702fe0c7e80b69763dcfb (patch) | |
tree | a9f6b04591b9087f4a64086c27ac46c09a2f82aa /arch/x86/include/asm/traps.h | |
parent | 4234653e882740cbf6625eeee294e388b3176583 (diff) | |
download | linux-a0d14b8909de55139b8702fe0c7e80b69763dcfb.tar.xz |
x86/mm, tracing: Fix CR2 corruption
Despite the current efforts to read CR2 before tracing happens there still
exist a number of possible holes:
idtentry page_fault do_page_fault has_error_code=1
call error_entry
TRACE_IRQS_OFF
call trace_hardirqs_off*
#PF // modifies CR2
CALL_enter_from_user_mode
__context_tracking_exit()
trace_user_exit(0)
#PF // modifies CR2
call do_page_fault
address = read_cr2(); /* whoopsie */
And similar for i386.
Fix it by pulling the CR2 read into the entry code, before any of that
stuff gets a chance to run and ruin things.
Reported-by: He Zhe <zhe.he@windriver.com>
Reported-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: jgross@suse.com
Cc: joel@joelfernandes.org
Link: https://lkml.kernel.org/r/20190711114336.116812491@infradead.org
Debugged-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/include/asm/traps.h')
-rw-r--r-- | arch/x86/include/asm/traps.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 7d6f3f3fad78..5dd1674ddf4c 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -74,14 +74,14 @@ dotraplinkage void do_invalid_TSS(struct pt_regs *regs, long error_code); dotraplinkage void do_segment_not_present(struct pt_regs *regs, long error_code); dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code); #ifdef CONFIG_X86_64 -dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code); +dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsigned long address); asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs); asmlinkage __visible notrace struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s); void __init trap_init(void); #endif dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code); -dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code); +dotraplinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address); dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code); dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code); dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code); |