Commit 82a592c1 authored by Madhavan T. Venkataraman's avatar Madhavan T. Venkataraman Committed by Will Deacon
Browse files

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: default avatarMadhavan T. Venkataraman <madvenka@linux.microsoft.com>
Reviewed-by: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220617180219.20352-3-madvenka@linux.microsoft.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent a019d8a2

arch/arm64/kernel/stacktrace.c

+20 −13
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ 
 * @kr_cur:      When KRETPROBES is selected, holds the kretprobe instance

 *               associated with the most recently encountered replacement lr

 *               value.

 *

 * @task:        The task being unwound.

 */

struct unwind_state {

	unsigned long fp;
@@ -48,10 +50,13 @@ struct unwind_state { 
#ifdef CONFIG_KRETPROBES

	struct llist_node *kr_cur;

#endif

	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;

#ifdef CONFIG_KRETPROBES

	state->kr_cur = NULL;

#endif
@@ -80,7 +85,7 @@ 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;
@@ -96,7 +101,7 @@ 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);
@@ -115,7 +120,7 @@ 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);
@@ -128,9 +133,9 @@ 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;
@@ -204,8 +209,7 @@ 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) {
@@ -213,7 +217,7 @@ 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;

	}
@@ -259,12 +263,15 @@ 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);

}