hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

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 <francis.deslauriers@efficios.com>
Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S . Miller <davem@davemloft.net>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-arch@vger.kernel.org
Cc: linux-cris-kernel@axis.com
Cc: mathieu.desnoyers@efficios.com
Link: http://lkml.kernel.org/r/150172795654.27216.9824039077047777477.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Masami Hiramatsu 2017-08-03 11:39:26 +09:00 committed by Ingo Molnar
parent 229a718605
commit d9f5f32a7d
1 changed files with 6 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/x86/kernel/kprobes/opt.c
View File

@ -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. */