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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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47ad7b9bbe
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>
64 lines
2.1 KiB
ArmAsm
64 lines
2.1 KiB
ArmAsm
/*
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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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#include <linux/linkage.h>
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#include <linux/unistd.h>
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#include <asm/irqflags.h>
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#include <asm/processor.h>
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#include <arch/abi.h>
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#include <arch/spr_def.h>
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#ifdef __tilegx__
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#define bnzt bnezt
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#endif
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STD_ENTRY(current_text_addr)
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{ move r0, lr; jrp lr }
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STD_ENDPROC(current_text_addr)
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STD_ENTRY(KBacktraceIterator_init_current)
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{ move r2, lr; lnk r1 }
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{ move r4, r52; addli r1, r1, KBacktraceIterator_init_current - . }
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{ move r3, sp; j _KBacktraceIterator_init_current }
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jrp lr /* keep backtracer happy */
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STD_ENDPROC(KBacktraceIterator_init_current)
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/* Loop forever on a nap during SMP boot. */
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STD_ENTRY(smp_nap)
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nap
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nop /* avoid provoking the icache prefetch with a jump */
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j smp_nap /* we are not architecturally guaranteed not to exit nap */
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jrp lr /* clue in the backtracer */
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STD_ENDPROC(smp_nap)
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/*
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* Enable interrupts racelessly and then nap until interrupted.
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* Architecturally, we are guaranteed that enabling interrupts via
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* mtspr to INTERRUPT_CRITICAL_SECTION only interrupts at the next PC.
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* This function's _cpu_idle_nap address is special; see intvec.S.
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* When interrupted at _cpu_idle_nap, we bump the PC forward 8, and
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* as a result return to the function that called _cpu_idle().
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*/
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STD_ENTRY(_cpu_idle)
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movei r1, 1
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IRQ_ENABLE_LOAD(r2, r3)
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mtspr INTERRUPT_CRITICAL_SECTION, r1
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IRQ_ENABLE_APPLY(r2, r3) /* unmask, but still with ICS set */
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mtspr INTERRUPT_CRITICAL_SECTION, zero
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.global _cpu_idle_nap
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_cpu_idle_nap:
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nap
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nop /* avoid provoking the icache prefetch with a jump */
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jrp lr
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STD_ENDPROC(_cpu_idle)
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