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author | Chris Metcalf <cmetcalf@ezchip.com> | 2015-05-08 17:27:35 +0300 |
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committer | Chris Metcalf <cmetcalf@ezchip.com> | 2015-05-11 18:22:40 +0300 |
commit | 47ad7b9bbeaac34e43d9dc8db796f1f68194b9ad (patch) | |
tree | d9c8efe315853965948f1f689def0a1e77b33695 /arch/tile/include/asm/thread_info.h | |
parent | e8200baa2fd2e9c4bc7abd824a9e675d914e54a0 (diff) | |
download | linux-47ad7b9bbeaac34e43d9dc8db796f1f68194b9ad.tar.xz |
tile: improve stack backtrace
This commit fixes a number of issues with the tile backtrace code.
- Don't try to identify userspace shared object or executable paths
if we are doing a backtrace from an interrupt; it's not legal,
and also unlikely to be interesting. Likewise, don't try to do
it for other address spaces, since d_path() assumes it is being
called in "current" context.
- Move "in_backtrace" from thread_struct to thread_info.
This way we can access it even if our stack thread_info has been
clobbered, which makes backtracing more robust.
- Avoid using "current" directly when testing for is_sigreturn().
Since "current" may be corrupt, we're better off using kbt->task
explicitly to look up the vdso_base for the current task.
Conveniently, this simplifies the internal APIs (we only need
one is_sigreturn() function now).
- Avoid bogus "Odd fault" warning when pc/sp/ex1 are all zero,
as is true for kernel threads above the last frame.
- Hook into Tejun Heo's dump_stack() framework in lib/dump_stack.c.
- Write last entry in save_stack_trace() as ULONG_MAX, not zero,
since ftrace (at least) relies on finding that marker.
- Implement save_stack_trace_regs() and save_strack_trace_user(),
and set CONFIG_USER_STACKTRACE_SUPPORT.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
Diffstat (limited to 'arch/tile/include/asm/thread_info.h')
-rw-r--r-- | arch/tile/include/asm/thread_info.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/tile/include/asm/thread_info.h b/arch/tile/include/asm/thread_info.h index f804c39a5e4d..dc1fb28d9636 100644 --- a/arch/tile/include/asm/thread_info.h +++ b/arch/tile/include/asm/thread_info.h @@ -42,6 +42,7 @@ struct thread_info { unsigned long unalign_jit_tmp[4]; /* temp r0..r3 storage */ void __user *unalign_jit_base; /* unalign fixup JIT base */ #endif + bool in_backtrace; /* currently doing backtrace? */ }; /* |