From 103b4cca60d2c8c51f1290cc984b7046ccb8b46d Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Fri, 22 Nov 2019 12:35:34 +0100 Subject: s390/unwind: unify task is current checks Avoid mixture of task == NULL and task == current meaning the same thing and simply always initialize task with current in unwind_start. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dumpstack.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'arch/s390/kernel/dumpstack.c') diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index 34bdc60c0b11..fc442aec0d96 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -93,8 +93,6 @@ int get_stack_info(unsigned long sp, struct task_struct *task, if (!sp) goto unknown; - task = task ? : current; - /* Check per-task stack */ if (in_task_stack(sp, task, info)) goto recursion_check; @@ -128,8 +126,6 @@ void show_stack(struct task_struct *task, unsigned long *stack) struct unwind_state state; printk("Call Trace:\n"); - if (!task) - task = current; unwind_for_each_frame(&state, task, NULL, (unsigned long) stack) printk(state.reliable ? " [<%016lx>] %pSR \n" : "([<%016lx>] %pSR)\n", -- cgit From 0610154650f161d56a0bef0d9678ae1de7360019 Mon Sep 17 00:00:00 2001 From: Vasily Gorbik Date: Fri, 22 Nov 2019 18:52:40 +0100 Subject: s390/test_unwind: print verbose unwinding results Add stack name, sp and reliable information into test unwinding results. Also consider ip outside of kernel text as failure if the state is reported reliable. Acked-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dumpstack.c | 1 + arch/s390/lib/test_unwind.c | 12 ++++++++++-- 2 files changed, 11 insertions(+), 2 deletions(-) (limited to 'arch/s390/kernel/dumpstack.c') diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index fc442aec0d96..d74e21a23703 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -38,6 +38,7 @@ const char *stack_type_name(enum stack_type type) return "unknown"; } } +EXPORT_SYMBOL_GPL(stack_type_name); static inline bool in_stack(unsigned long sp, struct stack_info *info, enum stack_type type, unsigned long low, diff --git a/arch/s390/lib/test_unwind.c b/arch/s390/lib/test_unwind.c index 687a6922beda..db94e657c056 100644 --- a/arch/s390/lib/test_unwind.c +++ b/arch/s390/lib/test_unwind.c @@ -56,11 +56,19 @@ static noinline int test_unwind(struct task_struct *task, struct pt_regs *regs, unsigned long addr = unwind_get_return_address(&state); char sym[KSYM_SYMBOL_LEN]; - if (!addr || frame_count == max_frames) + if (frame_count++ == max_frames) break; + if (state.reliable && !addr) { + pr_err("unwind state reliable but addr is 0\n"); + return -EINVAL; + } sprint_symbol(sym, addr); if (bt_pos < BT_BUF_SIZE) { - bt_pos += snprintf(bt + bt_pos, BT_BUF_SIZE - bt_pos, "%s\n", sym); + bt_pos += snprintf(bt + bt_pos, BT_BUF_SIZE - bt_pos, + state.reliable ? " [%-7s%px] %pSR\n" : + "([%-7s%px] %pSR)\n", + stack_type_name(state.stack_info.type), + (void *)state.sp, (void *)state.ip); if (bt_pos >= BT_BUF_SIZE) pr_err("backtrace buffer is too small\n"); } -- cgit From be2d11b2a1e86586ace9f6839a159b170b00f2b3 Mon Sep 17 00:00:00 2001 From: Miroslav Benes Date: Wed, 27 Nov 2019 19:35:19 +0100 Subject: s390/unwind: add stack pointer alignment sanity checks ABI requires SP to be aligned 8 bytes, report unwinding error otherwise. Link: https://lkml.kernel.org/r/20191106095601.29986-5-mbenes@suse.cz Reviewed-by: Heiko Carstens Tested-by: Miroslav Benes Signed-off-by: Miroslav Benes Signed-off-by: Vasily Gorbik --- arch/s390/kernel/dumpstack.c | 4 ++++ arch/s390/kernel/unwind_bc.c | 4 ++++ 2 files changed, 8 insertions(+) (limited to 'arch/s390/kernel/dumpstack.c') diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c index d74e21a23703..d306fe04489a 100644 --- a/arch/s390/kernel/dumpstack.c +++ b/arch/s390/kernel/dumpstack.c @@ -94,6 +94,10 @@ int get_stack_info(unsigned long sp, struct task_struct *task, if (!sp) goto unknown; + /* Sanity check: ABI requires SP to be aligned 8 bytes. */ + if (sp & 0x7) + goto unknown; + /* Check per-task stack */ if (in_task_stack(sp, task, info)) goto recursion_check; diff --git a/arch/s390/kernel/unwind_bc.c b/arch/s390/kernel/unwind_bc.c index ef42d5f77ce7..da2d4d4c5b0e 100644 --- a/arch/s390/kernel/unwind_bc.c +++ b/arch/s390/kernel/unwind_bc.c @@ -92,6 +92,10 @@ bool unwind_next_frame(struct unwind_state *state) } } + /* Sanity check: ABI requires SP to be aligned 8 bytes. */ + if (sp & 0x7) + goto out_err; + ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *) sp); /* Update unwind state */ -- cgit