![Chris Metcalf](/assets/img/avatar_default.png)
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>
72 lines
2.6 KiB
C
72 lines
2.6 KiB
C
/*
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*/
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#ifndef _ASM_TILE_STACK_H
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#define _ASM_TILE_STACK_H
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <asm/backtrace.h>
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#include <asm/page.h>
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#include <hv/hypervisor.h>
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/* Everything we need to keep track of a backtrace iteration */
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struct KBacktraceIterator {
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BacktraceIterator it;
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struct task_struct *task; /* task we are backtracing */
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int end; /* iteration complete. */
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int new_context; /* new context is starting */
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int profile; /* profiling, so stop on async intrpt */
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int verbose; /* printk extra info (don't want to
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* do this for profiling) */
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int is_current; /* backtracing current task */
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};
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/* Iteration methods for kernel backtraces */
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/*
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* Initialize a KBacktraceIterator from a task_struct, and optionally from
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* a set of registers. If the registers are omitted, the process is
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* assumed to be descheduled, and registers are read from the process's
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* thread_struct and stack. "verbose" means to printk some additional
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* information about fault handlers as we pass them on the stack.
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*/
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extern void KBacktraceIterator_init(struct KBacktraceIterator *kbt,
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struct task_struct *, struct pt_regs *);
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/* Initialize iterator based on current stack. */
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extern void KBacktraceIterator_init_current(struct KBacktraceIterator *kbt);
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/* Helper method for above. */
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extern void _KBacktraceIterator_init_current(struct KBacktraceIterator *kbt,
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ulong pc, ulong lr, ulong sp, ulong r52);
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/* No more frames? */
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extern int KBacktraceIterator_end(struct KBacktraceIterator *kbt);
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/* Advance to the next frame. */
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extern void KBacktraceIterator_next(struct KBacktraceIterator *kbt);
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/* Dump just the contents of the pt_regs structure. */
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extern void tile_show_regs(struct pt_regs *);
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/*
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* Dump stack given complete register info. Use only from the
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* architecture-specific code; show_stack()
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* and dump_stack() are architecture-independent entry points.
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*/
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extern void tile_show_stack(struct KBacktraceIterator *);
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#endif /* _ASM_TILE_STACK_H */
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