From 47ad7b9bbeaac34e43d9dc8db796f1f68194b9ad Mon Sep 17 00:00:00 2001 From: Chris Metcalf Date: Fri, 8 May 2015 10:27:35 -0400 Subject: 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 --- arch/tile/include/asm/processor.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/tile/include/asm/processor.h') diff --git a/arch/tile/include/asm/processor.h b/arch/tile/include/asm/processor.h index dd4f9f17e30a..139dfdee0134 100644 --- a/arch/tile/include/asm/processor.h +++ b/arch/tile/include/asm/processor.h @@ -111,8 +111,6 @@ struct thread_struct { unsigned long long interrupt_mask; /* User interrupt-control 0 state */ unsigned long intctrl_0; - /* Is this task currently doing a backtrace? */ - bool in_backtrace; /* Any other miscellaneous processor state bits */ unsigned long proc_status; #if !CHIP_HAS_FIXED_INTVEC_BASE() -- cgit