| Message ID | 20220617210717.27126-3-madvenka@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Reorganize the unwinder and implement stack trace reliability checks | expand |
On Fri, Jun 17, 2022 at 04:07:13PM -0500, madvenka@linux.microsoft.com wrote: > From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> > > 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> Mark. > --- > arch/arm64/kernel/stacktrace.c | 33 ++++++++++++++++++++------------- > 1 file changed, 20 insertions(+), 13 deletions(-) > > diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c > index e44f93ff25f0..8e43444d50e2 100644 > --- a/arch/arm64/kernel/stacktrace.c > +++ b/arch/arm64/kernel/stacktrace.c > @@ -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); > } > -- > 2.25.1 >
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index e44f93ff25f0..8e43444d50e2 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -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); }