Commit bd0b9067 authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Ingo Molnar

kprobes/x86: Fix kprobe-booster not to boost far call instructions

Fix the kprobe-booster not to boost far call instruction,
because a call may store the address in the single-step
execution buffer to the stack, which should be modified
after single stepping.

Currently, this instruction will be filtered as not
boostable in resume_execution(), so this is not a
critical issue.
Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David S . Miller <davem@davemloft.net>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: Ye Xiaolong <xiaolong.ye@intel.com>
Link: http://lkml.kernel.org/r/149076340615.22469.14066273186134229909.stgit@devboxSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent ef0eb2e6
...@@ -200,6 +200,8 @@ int can_boost(kprobe_opcode_t *opcodes, void *addr) ...@@ -200,6 +200,8 @@ int can_boost(kprobe_opcode_t *opcodes, void *addr)
return (opcode != 0x62 && opcode != 0x67); return (opcode != 0x62 && opcode != 0x67);
case 0x70: case 0x70:
return 0; /* can't boost conditional jump */ return 0; /* can't boost conditional jump */
case 0x90:
return opcode != 0x9a; /* can't boost call far */
case 0xc0: case 0xc0:
/* can't boost software-interruptions */ /* can't boost software-interruptions */
return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf; return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;
......
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