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/stack.h | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'arch/tile/include/asm/stack.h') diff --git a/arch/tile/include/asm/stack.h b/arch/tile/include/asm/stack.h index 0e9d382a2d45..c3cb42615a9f 100644 --- a/arch/tile/include/asm/stack.h +++ b/arch/tile/include/asm/stack.h @@ -58,17 +58,14 @@ extern int KBacktraceIterator_end(struct KBacktraceIterator *kbt); /* Advance to the next frame. */ extern void KBacktraceIterator_next(struct KBacktraceIterator *kbt); +/* Dump just the contents of the pt_regs structure. */ +extern void tile_show_regs(struct pt_regs *); + /* * Dump stack given complete register info. Use only from the * architecture-specific code; show_stack() - * and dump_stack() (in entry.S) are architecture-independent entry points. + * and dump_stack() are architecture-independent entry points. */ -extern void tile_show_stack(struct KBacktraceIterator *, int headers); - -/* Dump stack of current process, with registers to seed the backtrace. */ -extern void dump_stack_regs(struct pt_regs *); - -/* Helper method for assembly dump_stack(). */ -extern void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52); +extern void tile_show_stack(struct KBacktraceIterator *); #endif /* _ASM_TILE_STACK_H */ -- cgit