From: tip-bot for Andy Lutomirski <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: dvlasenk@redhat.com, hpa@zytor.com, mingo@kernel.org,
linux-kernel@vger.kernel.org, peterz@infradead.org,
luto@kernel.org, bp@alien8.de, torvalds@linux-foundation.org,
jpoimboe@redhat.com, tglx@linutronix.de, brgerst@gmail.com
Subject: [tip:x86/mm] x86/dumpstack: Try harder to get a call trace on stack overflow
Date: Fri, 15 Jul 2016 05:00:56 -0700 [thread overview]
Message-ID: <tip-9a2e9da3e003112399f2863b7b6b911043c01895@git.kernel.org> (raw)
In-Reply-To: <ee1690eb2715ccc5dc187fde94effa4ca0ccbbcd.1468527351.git.luto@kernel.org>
Commit-ID: 9a2e9da3e003112399f2863b7b6b911043c01895
Gitweb: http://git.kernel.org/tip/9a2e9da3e003112399f2863b7b6b911043c01895
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 14 Jul 2016 13:22:52 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 15 Jul 2016 10:26:26 +0200
x86/dumpstack: Try harder to get a call trace on stack overflow
If we overflow the stack, print_context_stack() will abort. Detect
this case and rewind back into the valid part of the stack so that
we can trace it.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ee1690eb2715ccc5dc187fde94effa4ca0ccbbcd.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/dumpstack.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index ef8017c..cc88e25 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -87,7 +87,7 @@ static inline int valid_stack_ptr(struct task_struct *task,
else
return 0;
}
- return p > t && p < t + THREAD_SIZE - size;
+ return p >= t && p < t + THREAD_SIZE - size;
}
unsigned long
@@ -98,6 +98,14 @@ print_context_stack(struct task_struct *task,
{
struct stack_frame *frame = (struct stack_frame *)bp;
+ /*
+ * If we overflowed the stack into a guard page, jump back to the
+ * bottom of the usable stack.
+ */
+ if ((unsigned long)task_stack_page(task) - (unsigned long)stack <
+ PAGE_SIZE)
+ stack = (unsigned long *)task_stack_page(task);
+
while (valid_stack_ptr(task, stack, sizeof(*stack), end)) {
unsigned long addr;
next prev parent reply other threads:[~2016-07-15 12:01 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-14 20:22 [PATCH 00/11] x86: misc prep patches for virtually mapped stacks Andy Lutomirski
2016-07-14 20:22 ` [PATCH 01/11] x86/mm/hotplug: Don't remove PGD entries in remove_pagetable() Andy Lutomirski
2016-07-15 11:59 ` [tip:x86/mm] " tip-bot for Ingo Molnar
2016-07-14 20:22 ` [PATCH 02/11] x86/cpa: In populate_pgd, don't set the pgd entry until it's populated Andy Lutomirski
2016-07-15 11:59 ` [tip:x86/mm] x86/mm/cpa: In populate_pgd(), don't set the PGD " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 03/11] x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables() Andy Lutomirski
2016-07-15 12:00 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 04/11] x86/dumpstack: Try harder to get a call trace on stack overflow Andy Lutomirski
2016-07-15 12:00 ` tip-bot for Andy Lutomirski [this message]
2016-07-14 20:22 ` [PATCH 05/11] x86/dumpstack/64: Handle faults when printing the "Stack:" part of an OOPS Andy Lutomirski
2016-07-15 12:01 ` [tip:x86/mm] x86/dumpstack/64: Handle faults when printing the "Stack: " " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 06/11] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm Andy Lutomirski
2016-07-15 12:01 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 07/11] x86/dumpstack: When OOPSing, rewind the stack before do_exit() Andy Lutomirski
2016-07-15 12:02 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 08/11] x86: Move uaccess_err and sig_on_uaccess_err to thread_struct Andy Lutomirski
2016-07-15 8:14 ` Ingo Molnar
2016-07-15 12:02 ` [tip:x86/mm] x86/uaccess: Move thread_info::uaccess_err and thread_info::sig_on_uaccess_err " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 09/11] x86: Move addr_limit " Andy Lutomirski
2016-07-15 12:03 ` [tip:x86/mm] x86/uaccess: Move thread_info::addr_limit " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 10/11] x86/smp: Remove stack_smp_processor_id() Andy Lutomirski
2016-07-15 12:04 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
2016-07-14 20:22 ` [PATCH 11/11] x86/smp: Remove unnecessary initialization of thread_info::cpu Andy Lutomirski
2016-07-15 12:04 ` [tip:x86/mm] " tip-bot for Andy Lutomirski
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