linux_dsm_epyc7002/arch/s390/kernel/stacktrace.c
Mark Brown 264c03a245 stacktrace: Remove reliable argument from arch_stack_walk() callback
Currently the callback passed to arch_stack_walk() has an argument called
reliable passed to it to indicate if the stack entry is reliable, a comment
says that this is used by some printk() consumers. However in the current
kernel none of the arch_stack_walk() implementations ever set this flag to
true and the only callback implementation we have is in the generic
stacktrace code which ignores the flag. It therefore appears that this
flag is redundant so we can simplify and clarify things by removing it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lore.kernel.org/r/20200914153409.25097-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18 14:24:16 +01:00

68 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Stack trace management functions
*
* Copyright IBM Corp. 2006
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
*/
#include <linux/stacktrace.h>
#include <asm/stacktrace.h>
#include <asm/unwind.h>
#include <asm/kprobes.h>
void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
struct task_struct *task, struct pt_regs *regs)
{
struct unwind_state state;
unsigned long addr;
unwind_for_each_frame(&state, task, regs, 0) {
addr = unwind_get_return_address(&state);
if (!addr || !consume_entry(cookie, addr))
break;
}
}
/*
* This function returns an error if it detects any unreliable features of the
* stack. Otherwise it guarantees that the stack trace is reliable.
*
* If the task is not 'current', the caller *must* ensure the task is inactive.
*/
int arch_stack_walk_reliable(stack_trace_consume_fn consume_entry,
void *cookie, struct task_struct *task)
{
struct unwind_state state;
unsigned long addr;
unwind_for_each_frame(&state, task, NULL, 0) {
if (state.stack_info.type != STACK_TYPE_TASK)
return -EINVAL;
if (state.regs)
return -EINVAL;
addr = unwind_get_return_address(&state);
if (!addr)
return -EINVAL;
#ifdef CONFIG_KPROBES
/*
* Mark stacktraces with kretprobed functions on them
* as unreliable.
*/
if (state.ip == (unsigned long)kretprobe_trampoline)
return -EINVAL;
#endif
if (!consume_entry(cookie, addr))
return -EINVAL;
}
/* Check for stack corruption */
if (unwind_error(&state))
return -EINVAL;
return 0;
}