From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/stacktrace.h | 3 +++
arch/arm64/kernel/stacktrace.c | 29 ++++++++++++++++-------------
2 files changed, 19 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 41ec360515f6..af423f5d7ad8 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -51,6 +51,8 @@ struct stack_info {
* @kr_cur: When KRETPROBES is selected, holds the kretprobe instance
* associated with the most recently encountered replacement lr
* value.
+ *
+ * @task: Pointer to the task structure.
*/
struct unwind_state {
unsigned long fp;
@@ -61,6 +63,7 @@ struct unwind_state {
#ifdef CONFIG_KRETPROBES
struct llist_node *kr_cur;
#endif
+ struct task_struct *task;
};
extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index b2b568e5deba..1b32e55735aa 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -33,8 +33,10 @@
*/
-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
@@ -57,9 +59,10 @@ static void unwind_init_common(struct unwind_state *state)
* TODO: document requirements here.
*/
static inline void unwind_init_from_regs(struct unwind_state *state,
+ struct task_struct *task,
struct pt_regs *regs)
{
- unwind_init_common(state);
+ unwind_init_common(state, task);
state->fp = regs->regs[29];
state->pc = regs->pc;
@@ -71,9 +74,10 @@ static inline void unwind_init_from_regs(struct unwind_state *state,
* Note: this is always inlined, and we expect our caller to be a noinline
* function, such that this starts from our caller's caller.
*/
-static __always_inline void unwind_init_from_current(struct unwind_state *state)
+static __always_inline void unwind_init_from_current(struct unwind_state *state,
+ struct task_struct *task)
{
- unwind_init_common(state);
+ unwind_init_common(state, task);
state->fp = (unsigned long)__builtin_frame_address(1);
state->pc = (unsigned long)__builtin_return_address(0);
@@ -87,7 +91,7 @@ static __always_inline void unwind_init_from_current(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);
@@ -100,11 +104,11 @@ 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)
{
unsigned long fp = state->fp;
struct stack_info info;
+ struct task_struct *tsk = state->task;
/* Final frame; nothing to unwind */
if (fp == (unsigned long)task_pt_regs(tsk)->stackframe)
@@ -176,8 +180,7 @@ 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,
bool (*fn)(void *, unsigned long), void *data)
{
while (1) {
@@ -185,7 +188,7 @@ static void notrace unwind(struct task_struct *tsk,
if (!fn(data, state->pc))
break;
- ret = unwind_next(tsk, state);
+ ret = unwind_next(state);
if (ret < 0)
break;
}
@@ -232,11 +235,11 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
struct unwind_state state;
if (regs)
- unwind_init_from_regs(&state, regs);
+ unwind_init_from_regs(&state, task, regs);
else if (task == current)
- unwind_init_from_current(&state);
+ unwind_init_from_current(&state, task);
else
unwind_init_from_task(&state, task);
- unwind(task, &state, consume_entry, cookie);
+ unwind(&state, consume_entry, cookie);
}
--
2.25.1
