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| author | Andy Lutomirski <luto@kernel.org> | 2017-08-09 14:39:45 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-08-10 13:14:58 +0200 |
| commit | 603e492e861861ddfec7139a007abad74f0d3af0 (patch) | |
| tree | ddc83a612c7960e21f889f1fd18ce44b817a182e /arch/x86/include/asm/ptrace.h | |
| parent | 8a9949bc71a71b3dd633255ebe8f8869b1f73474 (diff) | |
| download | linux-0-day-603e492e861861ddfec7139a007abad74f0d3af0.tar.gz linux-0-day-603e492e861861ddfec7139a007abad74f0d3af0.tar.xz | |
x86/asm/32: Fix regs_get_register() on segment registers
The segment register high words on x86_32 may contain garbage.
Teach regs_get_register() to read them as u16 instead of unsigned
long.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/0b76f6dbe477b7b1a81938fddcc3c483d48f0ff2.1502314765.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/ptrace.h')
| -rw-r--r-- | arch/x86/include/asm/ptrace.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index a29f828716999..91c04c8e67fab 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -196,6 +196,17 @@ static inline unsigned long regs_get_register(struct pt_regs *regs, if (offset == offsetof(struct pt_regs, sp) && regs->cs == __KERNEL_CS) return kernel_stack_pointer(regs); + + /* The selector fields are 16-bit. */ + if (offset == offsetof(struct pt_regs, cs) || + offset == offsetof(struct pt_regs, ss) || + offset == offsetof(struct pt_regs, ds) || + offset == offsetof(struct pt_regs, es) || + offset == offsetof(struct pt_regs, fs) || + offset == offsetof(struct pt_regs, gs)) { + return *(u16 *)((unsigned long)regs + offset); + + } #endif return *(unsigned long *)((unsigned long)regs + offset); } |