path: root/arch/powerpc/include
diff options
authorMike Wolf <mjw@linux.vnet.ibm.com>2011-03-21 11:14:53 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-03-21 11:18:14 +1100
commita71f5d5d279375205009a4be56a3cf6682921292 (patch)
treefde8b1e5958317268c9ce3b616cd4ee8d390502d /arch/powerpc/include
parentd6a2639b887fcf90b422caccca4aee216bd1120e (diff)
powerpc/ptrace: Remove BUG_ON when full register set not available
In some cases during a threaded core dump not all the threads will have a full register set. This happens when the signal causing the core dump races with a thread exiting. The race happens when the exiting thread has entered the kernel for the last time before the signal arrives, but doesn't get far enough through the exit code to avoid being included in the core dump. So we get a thread included in the core dump which is never going to go out to userspace again and only has a partial register set recorded Normally we would catch each thread as it is about to go into userspace and capture the full register set then. However, this exiting thread is never going to go out to userspace again, so we have no way to capture its full register set. It doesn't really matter, though, as this is a thread which is effectively already dead. So instead of hitting a BUG() in this case (a really bad choice of action in the first place), we use a poison value for the register values. [BenH]: Some cosmetic/stylistic changes and fix build on ppc32 Signed-off-by: Mike Wolf <mjw@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include')
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index 0175a676b34..48223f9b872 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -125,8 +125,10 @@ extern int ptrace_put_reg(struct task_struct *task, int regno,
#endif /* ! __powerpc64__ */
#define TRAP(regs) ((regs)->trap & ~0xF)
#ifdef __powerpc64__
+#define NV_REG_POISON 0xdeadbeefdeadbeefUL
#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
+#define NV_REG_POISON 0xdeadbeef
#define CHECK_FULL_REGS(regs) \
do { \
if ((regs)->trap & 1) \