* [PATCH 1/4] csky: Fixup perf callchain unwind
@ 2020-05-13 10:16 guoren
2020-05-13 10:16 ` [PATCH 2/4] csky: Fixup calltrace panic guoren
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: guoren @ 2020-05-13 10:16 UTC (permalink / raw)
To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Mao Han, Guo Ren
From: Mao Han <han_mao@linux.alibaba.com>
[ 5221.974084] Unable to handle kernel paging request at virtual address 0xfffff000, pc: 0x8002c18e
[ 5221.985929] Oops: 00000000
[ 5221.989488]
[ 5221.989488] CURRENT PROCESS:
[ 5221.989488]
[ 5221.992877] COMM=callchain_test PID=11962
[ 5221.995213] TEXT=00008000-000087e0 DATA=00009f1c-0000a018 BSS=0000a018-0000b000
[ 5221.999037] USER-STACK=7fc18e20 KERNEL-STACK=be204680
[ 5221.999037]
[ 5222.003292] PC: 0x8002c18e (perf_callchain_kernel+0x3e/0xd4)
[ 5222.007957] LR: 0x8002c198 (perf_callchain_kernel+0x48/0xd4)
[ 5222.074873] Call Trace:
[ 5222.074873] [<800a248e>] get_perf_callchain+0x20a/0x29c
[ 5222.074873] [<8009d964>] perf_callchain+0x64/0x80
[ 5222.074873] [<8009dc1c>] perf_prepare_sample+0x29c/0x4b8
[ 5222.074873] [<8009de6e>] perf_event_output_forward+0x36/0x98
[ 5222.074873] [<800497e0>] search_exception_tables+0x20/0x44
[ 5222.074873] [<8002cbb6>] do_page_fault+0x92/0x378
[ 5222.074873] [<80098608>] __perf_event_overflow+0x54/0xdc
[ 5222.074873] [<80098778>] perf_swevent_hrtimer+0xe8/0x164
[ 5222.074873] [<8002ddd0>] update_mmu_cache+0x0/0xd8
[ 5222.074873] [<8002c014>] user_backtrace+0x58/0xc4
[ 5222.074873] [<8002c0b4>] perf_callchain_user+0x34/0xd0
[ 5222.074873] [<800a2442>] get_perf_callchain+0x1be/0x29c
[ 5222.074873] [<8009d964>] perf_callchain+0x64/0x80
[ 5222.074873] [<8009d834>] perf_output_sample+0x78c/0x858
[ 5222.074873] [<8009dc1c>] perf_prepare_sample+0x29c/0x4b8
[ 5222.074873] [<8009de94>] perf_event_output_forward+0x5c/0x98
[ 5222.097846]
[ 5222.097846] [<800a0300>] perf_event_exit_task+0x58/0x43c
[ 5222.097846] [<8006c874>] hrtimer_interrupt+0x104/0x2ec
[ 5222.097846] [<800a0300>] perf_event_exit_task+0x58/0x43c
[ 5222.097846] [<80437bb6>] dw_apb_clockevent_irq+0x2a/0x4c
[ 5222.097846] [<8006c770>] hrtimer_interrupt+0x0/0x2ec
[ 5222.097846] [<8005f2e4>] __handle_irq_event_percpu+0xac/0x19c
[ 5222.097846] [<80437bb6>] dw_apb_clockevent_irq+0x2a/0x4c
[ 5222.097846] [<8005f408>] handle_irq_event_percpu+0x34/0x88
[ 5222.097846] [<8005f480>] handle_irq_event+0x24/0x64
[ 5222.097846] [<8006218c>] handle_level_irq+0x68/0xdc
[ 5222.097846] [<8005ec76>] __handle_domain_irq+0x56/0xa8
[ 5222.097846] [<80450e90>] ck_irq_handler+0xac/0xe4
[ 5222.097846] [<80029012>] csky_do_IRQ+0x12/0x24
[ 5222.097846] [<8002a3a0>] csky_irq+0x70/0x80
[ 5222.097846] [<800ca612>] alloc_set_pte+0xd2/0x238
[ 5222.097846] [<8002ddd0>] update_mmu_cache+0x0/0xd8
[ 5222.097846] [<800a0340>] perf_event_exit_task+0x98/0x43c
The original fp check doesn't base on the real kernal stack region.
Invalid fp address may cause kernel panic.
Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
---
arch/csky/kernel/perf_callchain.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c
index e68ff375c8f8..ab55e98ee8f6 100644
--- a/arch/csky/kernel/perf_callchain.c
+++ b/arch/csky/kernel/perf_callchain.c
@@ -12,12 +12,17 @@ struct stackframe {
static int unwind_frame_kernel(struct stackframe *frame)
{
- if (kstack_end((void *)frame->fp))
+ unsigned long low = (unsigned long)task_stack_page(current);
+ unsigned long high = low + THREAD_SIZE;
+
+ if (unlikely(frame->fp < low || frame->fp > high))
return -EPERM;
- if (frame->fp & 0x3 || frame->fp < TASK_SIZE)
+
+ if (kstack_end((void *)frame->fp) || frame->fp & 0x3)
return -EPERM;
*frame = *(struct stackframe *)frame->fp;
+
if (__kernel_text_address(frame->lr)) {
int graph = 0;
--
2.17.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/4] csky: Fixup calltrace panic 2020-05-13 10:16 [PATCH 1/4] csky: Fixup perf callchain unwind guoren @ 2020-05-13 10:16 ` guoren 2020-05-13 10:16 ` guoren 2020-05-13 10:16 ` [PATCH 3/4] csky: Fixup remove duplicate irq_disable guoren 2020-05-13 10:16 ` [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code guoren 2 siblings, 1 reply; 6+ messages in thread From: guoren @ 2020-05-13 10:16 UTC (permalink / raw) To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Guo Ren From: Guo Ren <guoren@linux.alibaba.com> The implementation of show_stack will panic with wrong fp: addr = *fp++; because the fp isn't checked properly. The current implementations of show_stack, wchan and stack_trace haven't been designed properly, so just deprecate them. This patch is a reference to riscv's way, all codes are modified from arm's. The patch is passed with: - cat /proc/<pid>/stack - cat /proc/<pid>/wchan - echo c > /proc/sysrq-trigger Signed-off-by: Guo Ren <guoren@linux.alibaba.com> --- arch/csky/Kconfig | 2 + arch/csky/Makefile | 2 +- arch/csky/include/asm/ptrace.h | 10 ++ arch/csky/include/asm/thread_info.h | 6 + arch/csky/kernel/Makefile | 2 +- arch/csky/kernel/dumpstack.c | 49 -------- arch/csky/kernel/process.c | 31 ----- arch/csky/kernel/stacktrace.c | 176 ++++++++++++++++++++++------ 8 files changed, 159 insertions(+), 119 deletions(-) delete mode 100644 arch/csky/kernel/dumpstack.c diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 94545d50d40f..bd31ab12f77d 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -8,6 +8,7 @@ config CSKY select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_QUEUED_RWLOCKS if NR_CPUS>2 + select ARCH_WANT_FRAME_POINTERS if !CPU_CK610 select COMMON_CLK select CLKSRC_MMIO select CSKY_MPINTC if CPU_CK860 @@ -38,6 +39,7 @@ config CSKY select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_AUDITSYSCALL select HAVE_COPY_THREAD_TLS + select HAVE_DEBUG_BUGVERBOSE select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_FUNCTION_TRACER diff --git a/arch/csky/Makefile b/arch/csky/Makefile index fb1bbbd91954..37f593a4bf53 100644 --- a/arch/csky/Makefile +++ b/arch/csky/Makefile @@ -47,7 +47,7 @@ ifeq ($(CSKYABI),abiv2) KBUILD_CFLAGS += -mno-stack-size endif -ifdef CONFIG_STACKTRACE +ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -mbacktrace endif diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h index aae5aa96cf54..bcfb7070e48d 100644 --- a/arch/csky/include/asm/ptrace.h +++ b/arch/csky/include/asm/ptrace.h @@ -58,6 +58,16 @@ static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) return regs->usp; } +static inline unsigned long frame_pointer(struct pt_regs *regs) +{ + return regs->regs[4]; +} +static inline void frame_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + regs->regs[4] = val; +} + extern int regs_query_register_offset(const char *name); extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n); diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index 5d33fcfd7f2a..d381a5752f0e 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -40,6 +40,12 @@ struct thread_info { #define thread_saved_fp(tsk) \ ((unsigned long)(((struct switch_stack *)(tsk->thread.ksp))->r8)) +#define thread_saved_sp(tsk) \ + ((unsigned long)(tsk->thread.ksp)) + +#define thread_saved_lr(tsk) \ + ((unsigned long)(((struct switch_stack *)(tsk->thread.ksp))->r15)) + static inline struct thread_info *current_thread_info(void) { unsigned long sp; diff --git a/arch/csky/kernel/Makefile b/arch/csky/kernel/Makefile index fd6d9dc8b7f3..37f37c0e934a 100644 --- a/arch/csky/kernel/Makefile +++ b/arch/csky/kernel/Makefile @@ -3,7 +3,7 @@ extra-y := head.o vmlinux.lds obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o obj-y += power.o syscall.o syscall_table.o setup.o -obj-y += process.o cpu-probe.o ptrace.o dumpstack.o +obj-y += process.o cpu-probe.o ptrace.o stacktrace.o obj-y += probes/ obj-$(CONFIG_MODULES) += module.o diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c deleted file mode 100644 index d67f9777cfd9..000000000000 --- a/arch/csky/kernel/dumpstack.c +++ /dev/null @@ -1,49 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. - -#include <linux/ptrace.h> - -int kstack_depth_to_print = 48; - -void show_trace(unsigned long *stack) -{ - unsigned long *stack_end; - unsigned long *stack_start; - unsigned long *fp; - unsigned long addr; - - addr = (unsigned long) stack & THREAD_MASK; - stack_start = (unsigned long *) addr; - stack_end = (unsigned long *) (addr + THREAD_SIZE); - - fp = stack; - pr_info("\nCall Trace:"); - - while (fp > stack_start && fp < stack_end) { -#ifdef CONFIG_STACKTRACE - addr = fp[1]; - fp = (unsigned long *) fp[0]; -#else - addr = *fp++; -#endif - if (__kernel_text_address(addr)) - pr_cont("\n[<%08lx>] %pS", addr, (void *)addr); - } - pr_cont("\n"); -} - -void show_stack(struct task_struct *task, unsigned long *stack) -{ - if (!stack) { - if (task) - stack = (unsigned long *)thread_saved_fp(task); - else -#ifdef CONFIG_STACKTRACE - asm volatile("mov %0, r8\n":"=r"(stack)::"memory"); -#else - stack = (unsigned long *)&stack; -#endif - } - - show_trace(stack); -} diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c index f7b231ca269a..4ad6db56c3cd 100644 --- a/arch/csky/kernel/process.c +++ b/arch/csky/kernel/process.c @@ -98,37 +98,6 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs) return 1; } -unsigned long get_wchan(struct task_struct *p) -{ - unsigned long lr; - unsigned long *fp, *stack_start, *stack_end; - int count = 0; - - if (!p || p == current || p->state == TASK_RUNNING) - return 0; - - stack_start = (unsigned long *)end_of_stack(p); - stack_end = (unsigned long *)(task_stack_page(p) + THREAD_SIZE); - - fp = (unsigned long *) thread_saved_fp(p); - do { - if (fp < stack_start || fp > stack_end) - return 0; -#ifdef CONFIG_STACKTRACE - lr = fp[1]; - fp = (unsigned long *)fp[0]; -#else - lr = *fp++; -#endif - if (!in_sched_functions(lr) && - __kernel_text_address(lr)) - return lr; - } while (count++ < 16); - - return 0; -} -EXPORT_SYMBOL(get_wchan); - #ifndef CONFIG_CPU_PM_NONE void arch_cpu_idle(void) { diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c index fec777a643f1..92809e1da723 100644 --- a/arch/csky/kernel/stacktrace.c +++ b/arch/csky/kernel/stacktrace.c @@ -1,57 +1,159 @@ // SPDX-License-Identifier: GPL-2.0 -/* Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. */ #include <linux/sched/debug.h> #include <linux/sched/task_stack.h> #include <linux/stacktrace.h> #include <linux/ftrace.h> +#include <linux/ptrace.h> -void save_stack_trace(struct stack_trace *trace) +#ifdef CONFIG_FRAME_POINTER + +struct stackframe { + unsigned long fp; + unsigned long ra; +}; + +void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, + bool (*fn)(unsigned long, void *), void *arg) { - save_stack_trace_tsk(current, trace); + unsigned long fp, sp, pc; + + if (regs) { + fp = frame_pointer(regs); + sp = user_stack_pointer(regs); + pc = instruction_pointer(regs); + } else if (task == NULL || task == current) { + const register unsigned long current_sp __asm__ ("sp"); + const register unsigned long current_fp __asm__ ("r8"); + fp = current_fp; + sp = current_sp; + pc = (unsigned long)walk_stackframe; + } else { + /* task blocked in __switch_to */ + fp = thread_saved_fp(task); + sp = thread_saved_sp(task); + pc = thread_saved_lr(task); + } + + for (;;) { + unsigned long low, high; + struct stackframe *frame; + + if (unlikely(!__kernel_text_address(pc) || fn(pc, arg))) + break; + + /* Validate frame pointer */ + low = sp; + high = ALIGN(sp, THREAD_SIZE); + if (unlikely(fp < low || fp > high || fp & 0x3)) + break; + /* Unwind stack frame */ + frame = (struct stackframe *)fp; + sp = fp; + fp = frame->fp; + pc = ftrace_graph_ret_addr(current, NULL, frame->ra, + (unsigned long *)(fp - 8)); + } } -EXPORT_SYMBOL_GPL(save_stack_trace); -void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +#else /* !CONFIG_FRAME_POINTER */ + +static void notrace walk_stackframe(struct task_struct *task, + struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg) { - unsigned long *fp, *stack_start, *stack_end; - unsigned long addr; - int skip = trace->skip; - int savesched; - int graph_idx = 0; + unsigned long sp, pc; + unsigned long *ksp; - if (tsk == current) { - asm volatile("mov %0, r8\n":"=r"(fp)); - savesched = 1; + if (regs) { + sp = user_stack_pointer(regs); + pc = instruction_pointer(regs); + } else if (task == NULL || task == current) { + const register unsigned long current_sp __asm__ ("sp"); + sp = current_sp; + pc = (unsigned long)walk_stackframe; } else { - fp = (unsigned long *)thread_saved_fp(tsk); - savesched = 0; + /* task blocked in __switch_to */ + sp = thread_saved_sp(task); + pc = thread_saved_lr(task); } - addr = (unsigned long) fp & THREAD_MASK; - stack_start = (unsigned long *) addr; - stack_end = (unsigned long *) (addr + THREAD_SIZE); - - while (fp > stack_start && fp < stack_end) { - unsigned long lpp, fpp; + if (unlikely(sp & 0x3)) + return; - fpp = fp[0]; - lpp = fp[1]; - if (!__kernel_text_address(lpp)) + ksp = (unsigned long *)sp; + while (!kstack_end(ksp)) { + if (__kernel_text_address(pc) && unlikely(fn(pc, arg))) break; - else - lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL); - - if (savesched || !in_sched_functions(lpp)) { - if (skip) { - skip--; - } else { - trace->entries[trace->nr_entries++] = lpp; - if (trace->nr_entries >= trace->max_entries) - break; - } - } - fp = (unsigned long *)fpp; + pc = (*ksp++) - 0x4; } } +#endif /* CONFIG_FRAME_POINTER */ + +static bool print_trace_address(unsigned long pc, void *arg) +{ + print_ip_sym(pc); + return false; +} + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + pr_cont("Call Trace:\n"); + walk_stackframe(task, NULL, print_trace_address, NULL); +} + +static bool save_wchan(unsigned long pc, void *arg) +{ + if (!in_sched_functions(pc)) { + unsigned long *p = arg; + *p = pc; + return true; + } + return false; +} + +unsigned long get_wchan(struct task_struct *task) +{ + unsigned long pc = 0; + + if (likely(task && task != current && task->state != TASK_RUNNING)) + walk_stackframe(task, NULL, save_wchan, &pc); + return pc; +} + +#ifdef CONFIG_STACKTRACE +static bool __save_trace(unsigned long pc, void *arg, bool nosched) +{ + struct stack_trace *trace = arg; + + if (unlikely(nosched && in_sched_functions(pc))) + return false; + if (unlikely(trace->skip > 0)) { + trace->skip--; + return false; + } + + trace->entries[trace->nr_entries++] = pc; + return (trace->nr_entries >= trace->max_entries); +} + +static bool save_trace(unsigned long pc, void *arg) +{ + return __save_trace(pc, arg, false); +} + +/* + * Save stack-backtrace addresses into a stack_trace buffer. + */ +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +{ + walk_stackframe(tsk, NULL, save_trace, trace); +} EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(NULL, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +#endif /* CONFIG_STACKTRACE */ -- 2.17.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/4] csky: Fixup calltrace panic 2020-05-13 10:16 ` [PATCH 2/4] csky: Fixup calltrace panic guoren @ 2020-05-13 10:16 ` guoren 0 siblings, 0 replies; 6+ messages in thread From: guoren @ 2020-05-13 10:16 UTC (permalink / raw) To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Guo Ren From: Guo Ren <guoren@linux.alibaba.com> The implementation of show_stack will panic with wrong fp: addr = *fp++; because the fp isn't checked properly. The current implementations of show_stack, wchan and stack_trace haven't been designed properly, so just deprecate them. This patch is a reference to riscv's way, all codes are modified from arm's. The patch is passed with: - cat /proc/<pid>/stack - cat /proc/<pid>/wchan - echo c > /proc/sysrq-trigger Signed-off-by: Guo Ren <guoren@linux.alibaba.com> --- arch/csky/Kconfig | 2 + arch/csky/Makefile | 2 +- arch/csky/include/asm/ptrace.h | 10 ++ arch/csky/include/asm/thread_info.h | 6 + arch/csky/kernel/Makefile | 2 +- arch/csky/kernel/dumpstack.c | 49 -------- arch/csky/kernel/process.c | 31 ----- arch/csky/kernel/stacktrace.c | 176 ++++++++++++++++++++++------ 8 files changed, 159 insertions(+), 119 deletions(-) delete mode 100644 arch/csky/kernel/dumpstack.c diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig index 94545d50d40f..bd31ab12f77d 100644 --- a/arch/csky/Kconfig +++ b/arch/csky/Kconfig @@ -8,6 +8,7 @@ config CSKY select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_QUEUED_RWLOCKS if NR_CPUS>2 + select ARCH_WANT_FRAME_POINTERS if !CPU_CK610 select COMMON_CLK select CLKSRC_MMIO select CSKY_MPINTC if CPU_CK860 @@ -38,6 +39,7 @@ config CSKY select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_AUDITSYSCALL select HAVE_COPY_THREAD_TLS + select HAVE_DEBUG_BUGVERBOSE select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_FUNCTION_TRACER diff --git a/arch/csky/Makefile b/arch/csky/Makefile index fb1bbbd91954..37f593a4bf53 100644 --- a/arch/csky/Makefile +++ b/arch/csky/Makefile @@ -47,7 +47,7 @@ ifeq ($(CSKYABI),abiv2) KBUILD_CFLAGS += -mno-stack-size endif -ifdef CONFIG_STACKTRACE +ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -mbacktrace endif diff --git a/arch/csky/include/asm/ptrace.h b/arch/csky/include/asm/ptrace.h index aae5aa96cf54..bcfb7070e48d 100644 --- a/arch/csky/include/asm/ptrace.h +++ b/arch/csky/include/asm/ptrace.h @@ -58,6 +58,16 @@ static inline unsigned long kernel_stack_pointer(struct pt_regs *regs) return regs->usp; } +static inline unsigned long frame_pointer(struct pt_regs *regs) +{ + return regs->regs[4]; +} +static inline void frame_pointer_set(struct pt_regs *regs, + unsigned long val) +{ + regs->regs[4] = val; +} + extern int regs_query_register_offset(const char *name); extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n); diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h index 5d33fcfd7f2a..d381a5752f0e 100644 --- a/arch/csky/include/asm/thread_info.h +++ b/arch/csky/include/asm/thread_info.h @@ -40,6 +40,12 @@ struct thread_info { #define thread_saved_fp(tsk) \ ((unsigned long)(((struct switch_stack *)(tsk->thread.ksp))->r8)) +#define thread_saved_sp(tsk) \ + ((unsigned long)(tsk->thread.ksp)) + +#define thread_saved_lr(tsk) \ + ((unsigned long)(((struct switch_stack *)(tsk->thread.ksp))->r15)) + static inline struct thread_info *current_thread_info(void) { unsigned long sp; diff --git a/arch/csky/kernel/Makefile b/arch/csky/kernel/Makefile index fd6d9dc8b7f3..37f37c0e934a 100644 --- a/arch/csky/kernel/Makefile +++ b/arch/csky/kernel/Makefile @@ -3,7 +3,7 @@ extra-y := head.o vmlinux.lds obj-y += entry.o atomic.o signal.o traps.o irq.o time.o vdso.o obj-y += power.o syscall.o syscall_table.o setup.o -obj-y += process.o cpu-probe.o ptrace.o dumpstack.o +obj-y += process.o cpu-probe.o ptrace.o stacktrace.o obj-y += probes/ obj-$(CONFIG_MODULES) += module.o diff --git a/arch/csky/kernel/dumpstack.c b/arch/csky/kernel/dumpstack.c deleted file mode 100644 index d67f9777cfd9..000000000000 --- a/arch/csky/kernel/dumpstack.c +++ /dev/null @@ -1,49 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. - -#include <linux/ptrace.h> - -int kstack_depth_to_print = 48; - -void show_trace(unsigned long *stack) -{ - unsigned long *stack_end; - unsigned long *stack_start; - unsigned long *fp; - unsigned long addr; - - addr = (unsigned long) stack & THREAD_MASK; - stack_start = (unsigned long *) addr; - stack_end = (unsigned long *) (addr + THREAD_SIZE); - - fp = stack; - pr_info("\nCall Trace:"); - - while (fp > stack_start && fp < stack_end) { -#ifdef CONFIG_STACKTRACE - addr = fp[1]; - fp = (unsigned long *) fp[0]; -#else - addr = *fp++; -#endif - if (__kernel_text_address(addr)) - pr_cont("\n[<%08lx>] %pS", addr, (void *)addr); - } - pr_cont("\n"); -} - -void show_stack(struct task_struct *task, unsigned long *stack) -{ - if (!stack) { - if (task) - stack = (unsigned long *)thread_saved_fp(task); - else -#ifdef CONFIG_STACKTRACE - asm volatile("mov %0, r8\n":"=r"(stack)::"memory"); -#else - stack = (unsigned long *)&stack; -#endif - } - - show_trace(stack); -} diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c index f7b231ca269a..4ad6db56c3cd 100644 --- a/arch/csky/kernel/process.c +++ b/arch/csky/kernel/process.c @@ -98,37 +98,6 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *pr_regs) return 1; } -unsigned long get_wchan(struct task_struct *p) -{ - unsigned long lr; - unsigned long *fp, *stack_start, *stack_end; - int count = 0; - - if (!p || p == current || p->state == TASK_RUNNING) - return 0; - - stack_start = (unsigned long *)end_of_stack(p); - stack_end = (unsigned long *)(task_stack_page(p) + THREAD_SIZE); - - fp = (unsigned long *) thread_saved_fp(p); - do { - if (fp < stack_start || fp > stack_end) - return 0; -#ifdef CONFIG_STACKTRACE - lr = fp[1]; - fp = (unsigned long *)fp[0]; -#else - lr = *fp++; -#endif - if (!in_sched_functions(lr) && - __kernel_text_address(lr)) - return lr; - } while (count++ < 16); - - return 0; -} -EXPORT_SYMBOL(get_wchan); - #ifndef CONFIG_CPU_PM_NONE void arch_cpu_idle(void) { diff --git a/arch/csky/kernel/stacktrace.c b/arch/csky/kernel/stacktrace.c index fec777a643f1..92809e1da723 100644 --- a/arch/csky/kernel/stacktrace.c +++ b/arch/csky/kernel/stacktrace.c @@ -1,57 +1,159 @@ // SPDX-License-Identifier: GPL-2.0 -/* Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd. */ #include <linux/sched/debug.h> #include <linux/sched/task_stack.h> #include <linux/stacktrace.h> #include <linux/ftrace.h> +#include <linux/ptrace.h> -void save_stack_trace(struct stack_trace *trace) +#ifdef CONFIG_FRAME_POINTER + +struct stackframe { + unsigned long fp; + unsigned long ra; +}; + +void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, + bool (*fn)(unsigned long, void *), void *arg) { - save_stack_trace_tsk(current, trace); + unsigned long fp, sp, pc; + + if (regs) { + fp = frame_pointer(regs); + sp = user_stack_pointer(regs); + pc = instruction_pointer(regs); + } else if (task == NULL || task == current) { + const register unsigned long current_sp __asm__ ("sp"); + const register unsigned long current_fp __asm__ ("r8"); + fp = current_fp; + sp = current_sp; + pc = (unsigned long)walk_stackframe; + } else { + /* task blocked in __switch_to */ + fp = thread_saved_fp(task); + sp = thread_saved_sp(task); + pc = thread_saved_lr(task); + } + + for (;;) { + unsigned long low, high; + struct stackframe *frame; + + if (unlikely(!__kernel_text_address(pc) || fn(pc, arg))) + break; + + /* Validate frame pointer */ + low = sp; + high = ALIGN(sp, THREAD_SIZE); + if (unlikely(fp < low || fp > high || fp & 0x3)) + break; + /* Unwind stack frame */ + frame = (struct stackframe *)fp; + sp = fp; + fp = frame->fp; + pc = ftrace_graph_ret_addr(current, NULL, frame->ra, + (unsigned long *)(fp - 8)); + } } -EXPORT_SYMBOL_GPL(save_stack_trace); -void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +#else /* !CONFIG_FRAME_POINTER */ + +static void notrace walk_stackframe(struct task_struct *task, + struct pt_regs *regs, bool (*fn)(unsigned long, void *), void *arg) { - unsigned long *fp, *stack_start, *stack_end; - unsigned long addr; - int skip = trace->skip; - int savesched; - int graph_idx = 0; + unsigned long sp, pc; + unsigned long *ksp; - if (tsk == current) { - asm volatile("mov %0, r8\n":"=r"(fp)); - savesched = 1; + if (regs) { + sp = user_stack_pointer(regs); + pc = instruction_pointer(regs); + } else if (task == NULL || task == current) { + const register unsigned long current_sp __asm__ ("sp"); + sp = current_sp; + pc = (unsigned long)walk_stackframe; } else { - fp = (unsigned long *)thread_saved_fp(tsk); - savesched = 0; + /* task blocked in __switch_to */ + sp = thread_saved_sp(task); + pc = thread_saved_lr(task); } - addr = (unsigned long) fp & THREAD_MASK; - stack_start = (unsigned long *) addr; - stack_end = (unsigned long *) (addr + THREAD_SIZE); - - while (fp > stack_start && fp < stack_end) { - unsigned long lpp, fpp; + if (unlikely(sp & 0x3)) + return; - fpp = fp[0]; - lpp = fp[1]; - if (!__kernel_text_address(lpp)) + ksp = (unsigned long *)sp; + while (!kstack_end(ksp)) { + if (__kernel_text_address(pc) && unlikely(fn(pc, arg))) break; - else - lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL); - - if (savesched || !in_sched_functions(lpp)) { - if (skip) { - skip--; - } else { - trace->entries[trace->nr_entries++] = lpp; - if (trace->nr_entries >= trace->max_entries) - break; - } - } - fp = (unsigned long *)fpp; + pc = (*ksp++) - 0x4; } } +#endif /* CONFIG_FRAME_POINTER */ + +static bool print_trace_address(unsigned long pc, void *arg) +{ + print_ip_sym(pc); + return false; +} + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + pr_cont("Call Trace:\n"); + walk_stackframe(task, NULL, print_trace_address, NULL); +} + +static bool save_wchan(unsigned long pc, void *arg) +{ + if (!in_sched_functions(pc)) { + unsigned long *p = arg; + *p = pc; + return true; + } + return false; +} + +unsigned long get_wchan(struct task_struct *task) +{ + unsigned long pc = 0; + + if (likely(task && task != current && task->state != TASK_RUNNING)) + walk_stackframe(task, NULL, save_wchan, &pc); + return pc; +} + +#ifdef CONFIG_STACKTRACE +static bool __save_trace(unsigned long pc, void *arg, bool nosched) +{ + struct stack_trace *trace = arg; + + if (unlikely(nosched && in_sched_functions(pc))) + return false; + if (unlikely(trace->skip > 0)) { + trace->skip--; + return false; + } + + trace->entries[trace->nr_entries++] = pc; + return (trace->nr_entries >= trace->max_entries); +} + +static bool save_trace(unsigned long pc, void *arg) +{ + return __save_trace(pc, arg, false); +} + +/* + * Save stack-backtrace addresses into a stack_trace buffer. + */ +void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) +{ + walk_stackframe(tsk, NULL, save_trace, trace); +} EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(NULL, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +#endif /* CONFIG_STACKTRACE */ -- 2.17.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 3/4] csky: Fixup remove duplicate irq_disable 2020-05-13 10:16 [PATCH 1/4] csky: Fixup perf callchain unwind guoren 2020-05-13 10:16 ` [PATCH 2/4] csky: Fixup calltrace panic guoren @ 2020-05-13 10:16 ` guoren 2020-05-13 10:16 ` [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code guoren 2 siblings, 0 replies; 6+ messages in thread From: guoren @ 2020-05-13 10:16 UTC (permalink / raw) To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Liu Yibin, Guo Ren From: Liu Yibin <jiulong@linux.alibaba.com> Interrupt has been disabled in __schedule() with local_irq_disable() and enabled in finish_task_switch->finish_lock_switch() with local_irq_enabled(), So needn't to disable irq here. Signed-off-by: Liu Yibin <jiulong@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> --- arch/csky/kernel/entry.S | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 364819536f2e..6a468ff75432 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -332,8 +332,6 @@ ENTRY(__switch_to) mfcr a2, psr /* Save PSR value */ stw a2, (a3, THREAD_SR) /* Save PSR in task struct */ - bclri a2, 6 /* Disable interrupts */ - mtcr a2, psr SAVE_SWITCH_STACK -- 2.17.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code 2020-05-13 10:16 [PATCH 1/4] csky: Fixup perf callchain unwind guoren 2020-05-13 10:16 ` [PATCH 2/4] csky: Fixup calltrace panic guoren 2020-05-13 10:16 ` [PATCH 3/4] csky: Fixup remove duplicate irq_disable guoren @ 2020-05-13 10:16 ` guoren 2020-05-13 10:16 ` guoren 2 siblings, 1 reply; 6+ messages in thread From: guoren @ 2020-05-13 10:16 UTC (permalink / raw) To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Guo Ren From: Guo Ren <guoren@linux.alibaba.com> All processes' PSR could success from SETUP_MMU, so need set it in INIT_THREAD again. And use a3 instead of r7 in __switch_to for code convention. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> --- arch/csky/include/asm/processor.h | 2 -- arch/csky/kernel/asm-offsets.c | 1 - arch/csky/kernel/entry.S | 10 ++-------- 3 files changed, 2 insertions(+), 11 deletions(-) diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h index c6bcd7f7c720..79eaaaed3d23 100644 --- a/arch/csky/include/asm/processor.h +++ b/arch/csky/include/asm/processor.h @@ -42,7 +42,6 @@ extern struct cpuinfo_csky cpu_data[]; struct thread_struct { unsigned long ksp; /* kernel stack pointer */ - unsigned long sr; /* saved status register */ unsigned long trap_no; /* saved status register */ /* FPU regs */ @@ -51,7 +50,6 @@ struct thread_struct { #define INIT_THREAD { \ .ksp = sizeof(init_stack) + (unsigned long) &init_stack, \ - .sr = DEFAULT_PSR_VALUE, \ } /* diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c index f8be348df9e4..bbc259eed233 100644 --- a/arch/csky/kernel/asm-offsets.c +++ b/arch/csky/kernel/asm-offsets.c @@ -19,7 +19,6 @@ int main(void) /* offsets into the thread struct */ DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp)); - DEFINE(THREAD_SR, offsetof(struct thread_struct, sr)); DEFINE(THREAD_FESR, offsetof(struct thread_struct, user_fp.fesr)); DEFINE(THREAD_FCR, offsetof(struct thread_struct, user_fp.fcr)); DEFINE(THREAD_FPREG, offsetof(struct thread_struct, user_fp.vr)); diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 6a468ff75432..3760397fdd3d 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -330,9 +330,6 @@ ENTRY(__switch_to) lrw a3, TASK_THREAD addu a3, a0 - mfcr a2, psr /* Save PSR value */ - stw a2, (a3, THREAD_SR) /* Save PSR in task struct */ - SAVE_SWITCH_STACK stw sp, (a3, THREAD_KSP) @@ -343,12 +340,9 @@ ENTRY(__switch_to) ldw sp, (a3, THREAD_KSP) /* Set next kernel sp */ - ldw a2, (a3, THREAD_SR) /* Set next PSR */ - mtcr a2, psr - #if defined(__CSKYABIV2__) - addi r7, a1, TASK_THREAD_INFO - ldw tls, (r7, TINFO_TP_VALUE) + addi a3, a1, TASK_THREAD_INFO + ldw tls, (a3, TINFO_TP_VALUE) #endif RESTORE_SWITCH_STACK -- 2.17.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code 2020-05-13 10:16 ` [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code guoren @ 2020-05-13 10:16 ` guoren 0 siblings, 0 replies; 6+ messages in thread From: guoren @ 2020-05-13 10:16 UTC (permalink / raw) To: linux-csky; +Cc: arnd, linux-kernel, linux-arch, guoren, Guo Ren From: Guo Ren <guoren@linux.alibaba.com> All processes' PSR could success from SETUP_MMU, so need set it in INIT_THREAD again. And use a3 instead of r7 in __switch_to for code convention. Signed-off-by: Guo Ren <guoren@linux.alibaba.com> --- arch/csky/include/asm/processor.h | 2 -- arch/csky/kernel/asm-offsets.c | 1 - arch/csky/kernel/entry.S | 10 ++-------- 3 files changed, 2 insertions(+), 11 deletions(-) diff --git a/arch/csky/include/asm/processor.h b/arch/csky/include/asm/processor.h index c6bcd7f7c720..79eaaaed3d23 100644 --- a/arch/csky/include/asm/processor.h +++ b/arch/csky/include/asm/processor.h @@ -42,7 +42,6 @@ extern struct cpuinfo_csky cpu_data[]; struct thread_struct { unsigned long ksp; /* kernel stack pointer */ - unsigned long sr; /* saved status register */ unsigned long trap_no; /* saved status register */ /* FPU regs */ @@ -51,7 +50,6 @@ struct thread_struct { #define INIT_THREAD { \ .ksp = sizeof(init_stack) + (unsigned long) &init_stack, \ - .sr = DEFAULT_PSR_VALUE, \ } /* diff --git a/arch/csky/kernel/asm-offsets.c b/arch/csky/kernel/asm-offsets.c index f8be348df9e4..bbc259eed233 100644 --- a/arch/csky/kernel/asm-offsets.c +++ b/arch/csky/kernel/asm-offsets.c @@ -19,7 +19,6 @@ int main(void) /* offsets into the thread struct */ DEFINE(THREAD_KSP, offsetof(struct thread_struct, ksp)); - DEFINE(THREAD_SR, offsetof(struct thread_struct, sr)); DEFINE(THREAD_FESR, offsetof(struct thread_struct, user_fp.fesr)); DEFINE(THREAD_FCR, offsetof(struct thread_struct, user_fp.fcr)); DEFINE(THREAD_FPREG, offsetof(struct thread_struct, user_fp.vr)); diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S index 6a468ff75432..3760397fdd3d 100644 --- a/arch/csky/kernel/entry.S +++ b/arch/csky/kernel/entry.S @@ -330,9 +330,6 @@ ENTRY(__switch_to) lrw a3, TASK_THREAD addu a3, a0 - mfcr a2, psr /* Save PSR value */ - stw a2, (a3, THREAD_SR) /* Save PSR in task struct */ - SAVE_SWITCH_STACK stw sp, (a3, THREAD_KSP) @@ -343,12 +340,9 @@ ENTRY(__switch_to) ldw sp, (a3, THREAD_KSP) /* Set next kernel sp */ - ldw a2, (a3, THREAD_SR) /* Set next PSR */ - mtcr a2, psr - #if defined(__CSKYABIV2__) - addi r7, a1, TASK_THREAD_INFO - ldw tls, (r7, TINFO_TP_VALUE) + addi a3, a1, TASK_THREAD_INFO + ldw tls, (a3, TINFO_TP_VALUE) #endif RESTORE_SWITCH_STACK -- 2.17.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-05-13 10:16 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-05-13 10:16 [PATCH 1/4] csky: Fixup perf callchain unwind guoren 2020-05-13 10:16 ` [PATCH 2/4] csky: Fixup calltrace panic guoren 2020-05-13 10:16 ` guoren 2020-05-13 10:16 ` [PATCH 3/4] csky: Fixup remove duplicate irq_disable guoren 2020-05-13 10:16 ` [PATCH 4/4] csky: Fixup remove unnecessary save/restore PSR code guoren 2020-05-13 10:16 ` guoren
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