mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-29 05:44:11 +00:00
70ccc7c066
As with the generic arch_stack_walk() code the ARM stack walk code takes a callback that is called per stack frame. Currently the ARM code always passes a struct stackframe to the callback and the generic code just passes the pc, however none of the users ever reference anything in the struct other than the pc value. The ARM code also uses a return type of int while the generic code uses a return type of bool though in both cases the return value is a boolean value and the sense is inverted between the two. In order to reduce code duplication when ARM is converted to use arch_stack_walk() change the signature and return sense of the ARM specific callback to match that of the generic code. Signed-off-by: Li Huafei <lihuafei1@huawei.com> Reviewed-by: Mark Brown <broonie@kernel.org> Reviewed-by: Linus Waleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
116 lines
2.6 KiB
C
116 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* ARM callchain support
|
|
*
|
|
* Copyright (C) 2009 picoChip Designs, Ltd., Jamie Iles
|
|
* Copyright (C) 2010 ARM Ltd., Will Deacon <will.deacon@arm.com>
|
|
*
|
|
* This code is based on the ARM OProfile backtrace code.
|
|
*/
|
|
#include <linux/perf_event.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#include <asm/stacktrace.h>
|
|
|
|
/*
|
|
* The registers we're interested in are at the end of the variable
|
|
* length saved register structure. The fp points at the end of this
|
|
* structure so the address of this struct is:
|
|
* (struct frame_tail *)(xxx->fp)-1
|
|
*
|
|
* This code has been adapted from the ARM OProfile support.
|
|
*/
|
|
struct frame_tail {
|
|
struct frame_tail __user *fp;
|
|
unsigned long sp;
|
|
unsigned long lr;
|
|
} __attribute__((packed));
|
|
|
|
/*
|
|
* Get the return address for a single stackframe and return a pointer to the
|
|
* next frame tail.
|
|
*/
|
|
static struct frame_tail __user *
|
|
user_backtrace(struct frame_tail __user *tail,
|
|
struct perf_callchain_entry_ctx *entry)
|
|
{
|
|
struct frame_tail buftail;
|
|
unsigned long err;
|
|
|
|
if (!access_ok(tail, sizeof(buftail)))
|
|
return NULL;
|
|
|
|
pagefault_disable();
|
|
err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail));
|
|
pagefault_enable();
|
|
|
|
if (err)
|
|
return NULL;
|
|
|
|
perf_callchain_store(entry, buftail.lr);
|
|
|
|
/*
|
|
* Frame pointers should strictly progress back up the stack
|
|
* (towards higher addresses).
|
|
*/
|
|
if (tail + 1 >= buftail.fp)
|
|
return NULL;
|
|
|
|
return buftail.fp - 1;
|
|
}
|
|
|
|
void
|
|
perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
|
|
{
|
|
struct frame_tail __user *tail;
|
|
|
|
perf_callchain_store(entry, regs->ARM_pc);
|
|
|
|
if (!current->mm)
|
|
return;
|
|
|
|
tail = (struct frame_tail __user *)regs->ARM_fp - 1;
|
|
|
|
while ((entry->nr < entry->max_stack) &&
|
|
tail && !((unsigned long)tail & 0x3))
|
|
tail = user_backtrace(tail, entry);
|
|
}
|
|
|
|
/*
|
|
* Gets called by walk_stackframe() for every stackframe. This will be called
|
|
* whist unwinding the stackframe and is like a subroutine return so we use
|
|
* the PC.
|
|
*/
|
|
static bool
|
|
callchain_trace(void *data, unsigned long pc)
|
|
{
|
|
struct perf_callchain_entry_ctx *entry = data;
|
|
perf_callchain_store(entry, pc);
|
|
return true;
|
|
}
|
|
|
|
void
|
|
perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs)
|
|
{
|
|
struct stackframe fr;
|
|
|
|
arm_get_current_stackframe(regs, &fr);
|
|
walk_stackframe(&fr, callchain_trace, entry);
|
|
}
|
|
|
|
unsigned long perf_instruction_pointer(struct pt_regs *regs)
|
|
{
|
|
return instruction_pointer(regs);
|
|
}
|
|
|
|
unsigned long perf_misc_flags(struct pt_regs *regs)
|
|
{
|
|
int misc = 0;
|
|
|
|
if (user_mode(regs))
|
|
misc |= PERF_RECORD_MISC_USER;
|
|
else
|
|
misc |= PERF_RECORD_MISC_KERNEL;
|
|
|
|
return misc;
|
|
}
|