From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Mon, 24 Jul 2017 12:26:23 +0100 Subject: [PATCH 4/4] arm64: unwind: remove sp from struct stackframe In-Reply-To: <20170724112623.26109-1-ard.biesheuvel@linaro.org> References: <20170724112623.26109-1-ard.biesheuvel@linaro.org> Message-ID: <20170724112623.26109-5-ard.biesheuvel@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The unwind code sets the sp member of struct stackframe to 'frame pointer + 0x10' unconditionally, without regard for whether doing so produces a legal value. So let's simply remove it now that we have stopped using it anyway. Cc: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Will Deacon Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/stacktrace.h | 1 - arch/arm64/kernel/perf_callchain.c | 1 - arch/arm64/kernel/process.c | 5 +---- arch/arm64/kernel/return_address.c | 1 - arch/arm64/kernel/stacktrace.c | 1 - arch/arm64/kernel/time.c | 1 - arch/arm64/kernel/traps.c | 2 -- 7 files changed, 1 insertion(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 5b6eafccc5d8..3bebab378c72 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -20,7 +20,6 @@ struct task_struct; struct stackframe { unsigned long fp; - unsigned long sp; unsigned long pc; #ifdef CONFIG_FUNCTION_GRAPH_TRACER unsigned int graph; diff --git a/arch/arm64/kernel/perf_callchain.c b/arch/arm64/kernel/perf_callchain.c index 713ca824f266..bcafd7dcfe8b 100644 --- a/arch/arm64/kernel/perf_callchain.c +++ b/arch/arm64/kernel/perf_callchain.c @@ -162,7 +162,6 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, } frame.fp = regs->regs[29]; - frame.sp = regs->sp; frame.pc = regs->pc; #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = current->curr_ret_stack; diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 659ae8094ed5..85b953dd023a 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -382,15 +382,12 @@ unsigned long get_wchan(struct task_struct *p) return 0; frame.fp = thread_saved_fp(p); - frame.sp = thread_saved_sp(p); frame.pc = thread_saved_pc(p); #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = p->curr_ret_stack; #endif do { - if (frame.sp < stack_page || - frame.sp >= stack_page + THREAD_SIZE || - unwind_frame(p, &frame)) + if (unwind_frame(p, &frame)) goto out; if (!in_sched_functions(frame.pc)) { ret = frame.pc; diff --git a/arch/arm64/kernel/return_address.c b/arch/arm64/kernel/return_address.c index 12a87f2600f2..933adbc0f654 100644 --- a/arch/arm64/kernel/return_address.c +++ b/arch/arm64/kernel/return_address.c @@ -42,7 +42,6 @@ void *return_address(unsigned int level) data.addr = NULL; frame.fp = (unsigned long)__builtin_frame_address(0); - frame.sp = current_stack_pointer; frame.pc = (unsigned long)return_address; /* dummy */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = current->curr_ret_stack; diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index b079af1ad145..cd5771d4e2d2 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -58,7 +58,6 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) !on_task_stack(tsk, fp)) return -EINVAL; - frame->sp = fp + 0x10; frame->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp)); frame->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8)); diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index da33c90248e9..a4391280fba9 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -50,7 +50,6 @@ unsigned long profile_pc(struct pt_regs *regs) return regs->pc; frame.fp = regs->regs[29]; - frame.sp = regs->sp; frame.pc = regs->pc; #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = -1; /* no task info */ diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index f2b284669587..9ba060b62837 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -155,14 +155,12 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) if (tsk == current) { frame.fp = (unsigned long)__builtin_frame_address(0); - frame.sp = current_stack_pointer; frame.pc = (unsigned long)dump_backtrace; } else { /* * task blocked in __switch_to */ frame.fp = thread_saved_fp(tsk); - frame.sp = thread_saved_sp(tsk); frame.pc = thread_saved_pc(tsk); } #ifdef CONFIG_FUNCTION_GRAPH_TRACER -- 2.9.3