diff options
| author | Masami Hiramatsu <[email protected]> | 2017-08-03 11:39:26 +0900 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2017-08-10 16:28:53 +0200 |
| commit | d9f5f32a7d17f4906a21ad59589853639a1328a0 (patch) | |
| tree | 4b54ad550325c872d237bc8bf0b4f610a82f3e20 | |
| parent | 229a71860547ec856b156179a9c6bef2de426f66 (diff) | |
kprobes/x86: Do not jump-optimize kprobes on irq entry code
Since the kernel segment registers are not prepared at the
entry of irq-entry code, if a kprobe on such code is
jump-optimized, accessing per-CPU variables may cause a
kernel panic.
However, if the kprobe is not optimized, it triggers an int3
exception and sets segment registers correctly.
With this patch we check the probe-address and if it is in the
irq-entry code, it prohibits optimizing such kprobes.
This means we can continue probing such interrupt handlers by kprobes
but it is not optimized anymore.
Reported-by: Francis Deslauriers <[email protected]>
Tested-by: Francis Deslauriers <[email protected]>
Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Anil S Keshavamurthy <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: David S . Miller <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/150172795654.27216.9824039077047777477.stgit@devbox
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | arch/x86/kernel/kprobes/opt.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 69ea0bc1cfa3..4f98aad38237 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -39,6 +39,7 @@ #include <asm/insn.h> #include <asm/debugreg.h> #include <asm/set_memory.h> +#include <asm/sections.h> #include "common.h" @@ -251,10 +252,12 @@ static int can_optimize(unsigned long paddr) /* * Do not optimize in the entry code due to the unstable - * stack handling. + * stack handling and registers setup. */ - if ((paddr >= (unsigned long)__entry_text_start) && - (paddr < (unsigned long)__entry_text_end)) + if (((paddr >= (unsigned long)__entry_text_start) && + (paddr < (unsigned long)__entry_text_end)) || + ((paddr >= (unsigned long)__irqentry_text_start) && + (paddr < (unsigned long)__irqentry_text_end))) return 0; /* Check there is enough space for a relative jump. */ |