Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-29 23:51:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

x86/dumpstack: Add support for unwinding empty IRQ stacks

Browse Source 
When an interrupt happens in entry code while running on a software IRQ
stack, and the IRQ stack was empty, regs->sp will contain the stack end
address (e.g., irq_stack_ptr).  If the regs are passed to dump_trace(),
get_stack_info() will report STACK_TYPE_UNKNOWN, causing dump_trace() to
return prematurely without trying to go to the next stack.

Update the bounds checking for software interrupt stacks so that the
ending address is now considered part of the stack.

This means that it's now possible for the 'walk_stack' callbacks --
print_context_stack() and print_context_stack_bp() -- to be called with
an empty stack.  But that's fine; they're already prepared to deal with
that due to their on_stack() checks.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/5a5e5de92dcf11e8dc6b6e8e50ad7639d067830b.1473905218.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Josh Poimboeuf 2016-09-14 21:07:43 -05:00 committed by Ingo Molnar
parent cb76c93982
commit 5fe599e02e
2 changed files with 15 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/x86/kernel/dumpstack_32.c
View File

@ -35,7 +35,11 @@ static bool in_hardirq_stack(unsigned long *stack, struct stack_info *info)
unsigned long *begin = (unsigned long *)this_cpu_read(hardirq_stack);
unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
if (stack < begin || stack >= end)
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
if (stack < begin || stack > end)
return false;
info->type = STACK_TYPE_IRQ;
@ -56,7 +60,11 @@ static bool in_softirq_stack(unsigned long *stack, struct stack_info *info)
unsigned long *begin = (unsigned long *)this_cpu_read(softirq_stack);
unsigned long *end = begin + (THREAD_SIZE / sizeof(long));
if (stack < begin || stack >= end)
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
if (stack < begin || stack > end)
return false;
info->type = STACK_TYPE_SOFTIRQ;

6
arch/x86/kernel/dumpstack_64.c
View File

@ -90,7 +90,11 @@ static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
unsigned long *end = (unsigned long *)this_cpu_read(irq_stack_ptr);
unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
if (stack < begin || stack >= end)
/*
* This is a software stack, so 'end' can be a valid stack pointer.
* It just means the stack is empty.
*/
if (stack < begin || stack > end)
return false;
info->type = STACK_TYPE_IRQ;