BACKPORT: arm64: Copy the task argument to unwind_state

Copy the task argument passed to arch_stack_walk() to unwind_state so that
it can be passed to unwind functions via unwind_state rather than as a
separate argument. The task is a fundamental part of the unwind state.

Signed-off-by: Madhavan T. Venkataraman <madvenka@linux.microsoft.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220617180219.20352-3-madvenka@linux.microsoft.com
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 82a592c13b)
[willdeacon@: Resolve context conflict with kretprobes field in
 'struct unwind_state']
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Icf29c7da8111dd5f7a25d99e6277a99c78e1ec23
This commit is contained in:
Madhavan T. Venkataraman
2022-06-17 13:02:15 -05:00
committed by Quentin Perret
parent e12793be98
commit b922edc361

View File

@@ -34,6 +34,8 @@
* @prev_type: The type of stack this frame record was on, or a synthetic
* value of STACK_TYPE_UNKNOWN. This is used to detect a
* transition from one stack to another.
*
* @task: The task being unwound.
*/
struct unwind_state {
unsigned long fp;
@@ -41,10 +43,14 @@ struct unwind_state {
DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
unsigned long prev_fp;
enum stack_type prev_type;
struct task_struct *task;
};
static void unwind_init_common(struct unwind_state *state)
static void unwind_init_common(struct unwind_state *state,
struct task_struct *task)
{
state->task = task;
/*
* Prime the first unwind.
*
@@ -69,7 +75,7 @@ static void unwind_init_common(struct unwind_state *state)
static inline void unwind_init_from_regs(struct unwind_state *state,
struct pt_regs *regs)
{
unwind_init_common(state);
unwind_init_common(state, current);
state->fp = regs->regs[29];
state->pc = regs->pc;
@@ -85,7 +91,7 @@ static inline void unwind_init_from_regs(struct unwind_state *state,
*/
static __always_inline void unwind_init_from_caller(struct unwind_state *state)
{
unwind_init_common(state);
unwind_init_common(state, current);
state->fp = (unsigned long)__builtin_frame_address(1);
state->pc = (unsigned long)__builtin_return_address(0);
@@ -104,7 +110,7 @@ static __always_inline void unwind_init_from_caller(struct unwind_state *state)
static inline void unwind_init_from_task(struct unwind_state *state,
struct task_struct *task)
{
unwind_init_common(state);
unwind_init_common(state, task);
state->fp = thread_saved_fp(task);
state->pc = thread_saved_pc(task);
@@ -117,9 +123,9 @@ static inline void unwind_init_from_task(struct unwind_state *state,
* records (e.g. a cycle), determined based on the location and fp value of A
* and the location (but not the fp value) of B.
*/
static int notrace unwind_next(struct task_struct *tsk,
struct unwind_state *state)
static int notrace unwind_next(struct unwind_state *state)
{
struct task_struct *tsk = state->task;
unsigned long fp = state->fp;
struct stack_info info;
@@ -189,8 +195,7 @@ static int notrace unwind_next(struct task_struct *tsk,
}
NOKPROBE_SYMBOL(unwind_next);
static void notrace unwind(struct task_struct *tsk,
struct unwind_state *state,
static void notrace unwind(struct unwind_state *state,
stack_trace_consume_fn consume_entry, void *cookie)
{
while (1) {
@@ -198,7 +203,7 @@ static void notrace unwind(struct task_struct *tsk,
if (!consume_entry(cookie, state->pc))
break;
ret = unwind_next(tsk, state);
ret = unwind_next(state);
if (ret < 0)
break;
}
@@ -245,12 +250,15 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
{
struct unwind_state state;
if (regs)
if (regs) {
if (task != current)
return;
unwind_init_from_regs(&state, regs);
else if (task == current)
} else if (task == current) {
unwind_init_from_caller(&state);
else
} else {
unwind_init_from_task(&state, task);
}
unwind(task, &state, consume_entry, cookie);
unwind(&state, consume_entry, cookie);
}