From: Li Zhong <zhong@linux•vnet.ibm.com>
To: PowerPC email list <linuxppc-dev@lists•ozlabs.org>
Cc: Paul Mackerras <paulus@samba•org>
Subject: [PATCH] powerpc: Fix MAX_STACK_TRACE_ENTRIES too low warning again
Date: Tue, 07 May 2013 10:32:58 +0800 [thread overview]
Message-ID: <1367893978.3083.13.camel@ThinkPad-T5421> (raw)
Saw this warning again, and this time from the ret_from_fork path.
It seems we could clear the back chain earlier in copy_thread(), which
could cover both path, and also fix potential lockdep usage in
schedule_tail(), or exception occurred before we clear the back chain.
Signed-off-by: Li Zhong <zhong@linux•vnet.ibm.com>
---
arch/powerpc/kernel/entry_32.S | 2 --
arch/powerpc/kernel/entry_64.S | 2 --
arch/powerpc/kernel/process.c | 1 +
3 files changed, 1 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index e514de5..d22e73e 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -439,8 +439,6 @@ ret_from_fork:
ret_from_kernel_thread:
REST_NVGPRS(r1)
bl schedule_tail
- li r3,0
- stw r3,0(r1)
mtlr r14
mr r3,r15
PPC440EP_ERR42
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 3fe5259..48e8a86 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -376,8 +376,6 @@ _GLOBAL(ret_from_fork)
_GLOBAL(ret_from_kernel_thread)
bl .schedule_tail
REST_NVGPRS(r1)
- li r3,0
- std r3,0(r1)
ld r14, 0(r14)
mtlr r14
mr r3,r15
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ceb4e7b..2c9fc5e 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -973,6 +973,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
*/
sp -= sizeof(struct pt_regs);
kregs = (struct pt_regs *) sp;
+ kregs->gpr[1] = 0;
sp -= STACK_FRAME_OVERHEAD;
p->thread.ksp = sp;
p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
--
1.7.1
next reply other threads:[~2013-05-07 2:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-07 2:32 Li Zhong [this message]
2013-05-07 8:29 ` [PATCH] powerpc: Fix MAX_STACK_TRACE_ENTRIES too low warning again Li Zhong
2013-05-07 8:44 ` [PATCH v2] " Li Zhong
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