3:44 p.m.
Cmd bt will list multi-stacks of one task. After we "set <pid>" switch
context to one task, we first need a bt call to detect the multi-stacks,
however we don't want any console output from it, so a nullfp is used for
output receive. The silent bt call is only triggered once as part of task
context switch by cmd set.
A array of user_regs pointers is reserved for each supported arch. If one
extra stack found, a user_regs structure will be allocated for storing regs
value of the stack.
Co-developed-by: Alexey Makhalov <alexey.makhalov(a)broadcom.com>
Co-developed-by: Tao Liu <ltao(a)redhat.com>
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
arm64.c | 4 ++++
crash_target.c | 7 +++++++
kernel.c | 43 +++++++++++++++++++++++++++++++++++++++++++
ppc64.c | 4 ++++
task.c | 4 ++--
x86_64.c | 3 +++
6 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/arm64.c b/arm64.c
index 1cdde5f..8291301 100644
--- a/arm64.c
+++ b/arm64.c
@@ -126,6 +126,10 @@ struct user_regs_bitmap_struct {
ulong bitmap[32];
};
+#define MAX_EXCEPTION_STACKS 7
+ulong extra_stacks_idx = 0;
+struct user_regs_bitmap_struct *extra_stacks_regs[MAX_EXCEPTION_STACKS] = {0};
+
static inline bool is_mte_kvaddr(ulong addr)
{
/* check for ARM64_MTE enabled */
diff --git a/crash_target.c b/crash_target.c
index 71998ef..ad1480c 100644
--- a/crash_target.c
+++ b/crash_target.c
@@ -31,6 +31,9 @@ extern "C" int crash_get_current_task_reg (int regno, const
char *regname,
extern "C" int gdb_change_thread_context (void);
extern "C" int gdb_add_substack (int);
extern "C" void crash_get_current_task_info(unsigned long *pid, char **comm);
+#if defined (X86_64) || defined (ARM64) || defined (PPC64)
+extern "C" void silent_call_bt(void);
+#endif
/* The crash target. */
@@ -164,6 +167,10 @@ gdb_change_thread_context (void)
/* 3rd, refresh regcache for tid 0 */
target_fetch_registers(get_thread_regcache(inferior_thread()), -1);
reinit_frame_cache();
+#if defined (X86_64) || defined (ARM64) || defined (PPC64)
+ /* 4th, invoke bt silently to refresh the additional stacks */
+ silent_call_bt();
+#endif
return TRUE;
}
diff --git a/kernel.c b/kernel.c
index 612b956..18b125c 100644
--- a/kernel.c
+++ b/kernel.c
@@ -12002,3 +12002,46 @@ int get_linux_banner_from_vmlinux(char *buf, size_t size)
return TRUE;
}
+
+#if defined(X86_64) || defined(ARM64) || defined(PPC64)
+extern ulong extra_stacks_idx;
+extern void *extra_stacks_regs[];
+void silent_call_bt(void)
+{
+ jmp_buf main_loop_env_save;
+ unsigned long long flags_save = pc->flags;
+ FILE *fp_save = fp;
+ FILE *error_fp_save = pc->error_fp;
+ /* Redirect all cmd_bt() outputs into null */
+ fp = pc->nullfp;
+ pc->error_fp = pc->nullfp;
+
+ for (int i = 0; i < extra_stacks_idx; i++) {
+ /* Note: GETBUF/FREEBUF is not applicable for extra_stacks_regs,
+ because we are reserving extra_stacks_regs by cmd_bt()
+ for later use. But GETBUF/FREEBUF is designed for use only
+ within one cmd. See process_command_line() -> restore_sanity()
+ -> free_all_bufs(). So we use malloc/free instead. */
+ free(extra_stacks_regs[i]);
+ extra_stacks_regs[i] = NULL;
+ }
+ /* Prepare args used by cmd_bt() */
+ sprintf(pc->command_line, "bt\n");
+ argcnt = parse_line(pc->command_line, args);
+ optind = 1;
+ pc->flags |= RUNTIME;
+
+ /* Catch error FATAL generated by cmd_bt() if any */
+ memcpy(&main_loop_env_save, &pc->main_loop_env, sizeof(jmp_buf));
+ if (setjmp(pc->main_loop_env)) {
+ goto out;
+ }
+ cmd_bt();
+out:
+ /* Restore all */
+ memcpy(&pc->main_loop_env, &main_loop_env_save, sizeof(jmp_buf));
+ pc->flags = flags_save;
+ fp = fp_save;
+ pc->error_fp = error_fp_save;
+}
+#endif
diff --git a/ppc64.c b/ppc64.c
index 7ac12fe..532eb3f 100644
--- a/ppc64.c
+++ b/ppc64.c
@@ -80,6 +80,10 @@ struct user_regs_bitmap_struct {
ulong bitmap[32];
};
+#define MAX_EXCEPTION_STACKS 7
+ulong extra_stacks_idx = 0;
+struct user_regs_bitmap_struct *extra_stacks_regs[MAX_EXCEPTION_STACKS] = {0};
+
static int is_opal_context(ulong sp, ulong nip)
{
uint64_t opal_start, opal_end;
diff --git a/task.c b/task.c
index 49f771e..869f584 100644
--- a/task.c
+++ b/task.c
@@ -3061,7 +3061,7 @@ sort_context_array(void)
curtask = CURRENT_TASK();
qsort((void *)tt->context_array, (size_t)tt->running_tasks,
sizeof(struct task_context), sort_by_pid);
- set_context(curtask, NO_PID, TRUE);
+ set_context(curtask, NO_PID, FALSE);
sort_context_by_task();
}
@@ -3108,7 +3108,7 @@ sort_context_array_by_last_run(void)
curtask = CURRENT_TASK();
qsort((void *)tt->context_array, (size_t)tt->running_tasks,
sizeof(struct task_context), sort_by_last_run);
- set_context(curtask, NO_PID, TRUE);
+ set_context(curtask, NO_PID, FALSE);
sort_context_by_task();
}
diff --git a/x86_64.c b/x86_64.c
index a46fb9d..ee23d8b 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -160,6 +160,9 @@ struct user_regs_bitmap_struct {
ulong bitmap[32];
};
+ulong extra_stacks_idx = 0;
+struct user_regs_bitmap_struct *extra_stacks_regs[MAX_EXCEPTION_STACKS] = {0};
+
/*
* Do all necessary machine-specific setup here. This is called several
* times during initialization.
--
2.47.0