linux/arch/x86_64
Jim Keniston 8bf1101bd5 [PATCH] kprobes: Fix return probes on sys_execve
Fix a bug in kprobes that can cause an Oops or even a crash when a return
probe is installed on one of the following functions: sys_execve,
do_execve, load_*_binary, flush_old_exec, or flush_thread.  The fix is to
remove the call to kprobe_flush_task() in flush_thread().  This fix has
been tested on all architectures for which the return-probes feature has
been implemented (i386, x86_64, ppc64, ia64).  Please apply.

BACKGROUND

Up to now, we have called kprobe_flush_task() under two situations: when a
task exits, and when it execs.  Flushing kretprobe_instances on exit is
correct because (a) do_exit() doesn't return, and (b) one or more
return-probed functions may be active when a task calls do_exit().  Neither
is the case for sys_execve() and its callees.

Initially, the mistaken call to kprobe_flush_task() on exec was harmless
because we put the "real" return address of each active probed function
back in the stack, just to be safe, when we recycled its
kretprobe_instance.  When support for ppc64 and ia64 was added, this safety
measure couldn't be employed, and was eventually dropped even for i386 and
x86_64.  sys_execve() and its callees were informally blacklisted for
return probes until this fix was developed.

Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23 16:08:39 -08:00
..
boot [PATCH] x86-64: Fix gcc 4 warnings about pointer signedness 2005-09-12 10:50:56 -07:00
crypto [PATCH] x86_64: add MODULE_ALIAS for aes 2005-08-08 15:29:13 -07:00
ia32 Merge x86-64 update from Andi 2005-11-14 19:56:02 -08:00
kernel [PATCH] kprobes: Fix return probes on sys_execve 2005-11-23 16:08:39 -08:00
lib [PATCH] x86_64: Remove optimization for B stepping AMD K8 2005-11-14 19:55:17 -08:00
mm [PATCH] x86_64: Fix sparse mem 2005-11-14 19:55:18 -08:00
oprofile [PATCH] Move Kprobes and Oprofile to "Instrumentation Support" menu 2005-11-07 07:53:35 -08:00
pci [PATCH] x86-64: Use ACPI PXM to parse PCI<->node assignments 2005-09-12 10:49:57 -07:00
defconfig [PATCH] x86_64: Update defconfig 2005-11-14 19:55:12 -08:00
Kconfig Merge x86-64 update from Andi 2005-11-14 19:56:02 -08:00
Kconfig.debug Merge x86-64 update from Andi 2005-11-14 19:56:02 -08:00
Makefile kbuild: alpha,x86_64 use generic asm-offsets.h support 2005-09-09 21:28:48 +02:00