From 162bc7f5afd75b72acbe3c5f3488ef7e64a3fe36 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 4 Dec 2018 19:38:28 -0800 Subject: kdb: Don't back trace on a cpu that didn't round up If you have a CPU that fails to round up and then run 'btc' you'll end up crashing in kdb becaue we dereferenced NULL. Let's add a check. It's wise to also set the task to NULL when leaving the debugger so that if we fail to round up on a later entry into the debugger we won't backtrace a stale task. Signed-off-by: Douglas Anderson Acked-by: Daniel Thompson Signed-off-by: Daniel Thompson --- kernel/debug/kdb/kdb_bt.c | 11 ++++++++++- kernel/debug/kdb/kdb_debugger.c | 7 ------- 2 files changed, 10 insertions(+), 8 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c index 7921ae4fca8d..7e2379aa0a1e 100644 --- a/kernel/debug/kdb/kdb_bt.c +++ b/kernel/debug/kdb/kdb_bt.c @@ -186,7 +186,16 @@ kdb_bt(int argc, const char **argv) kdb_printf("btc: cpu status: "); kdb_parse("cpu\n"); for_each_online_cpu(cpu) { - sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu)); + void *kdb_tsk = KDB_TSK(cpu); + + /* If a CPU failed to round up we could be here */ + if (!kdb_tsk) { + kdb_printf("WARNING: no task for cpu %ld\n", + cpu); + continue; + } + + sprintf(buf, "btt 0x%px\n", kdb_tsk); kdb_parse(buf); touch_nmi_watchdog(); } diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c index 15e1a7af5dd0..53a0df6e4d92 100644 --- a/kernel/debug/kdb/kdb_debugger.c +++ b/kernel/debug/kdb/kdb_debugger.c @@ -118,13 +118,6 @@ int kdb_stub(struct kgdb_state *ks) kdb_bp_remove(); KDB_STATE_CLEAR(DOING_SS); KDB_STATE_SET(PAGER); - /* zero out any offline cpu data */ - for_each_present_cpu(i) { - if (!cpu_online(i)) { - kgdb_info[i].debuggerinfo = NULL; - kgdb_info[i].task = NULL; - } - } if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) { ks->pass_exception = 1; KDB_FLAG_SET(CATASTROPHIC); -- cgit v1.2.3 From 7faedcd4de4356dfcda30841a5ffef3bf35fa06c Mon Sep 17 00:00:00 2001 From: Nicholas Mc Guire Date: Fri, 20 Jul 2018 11:23:37 +0200 Subject: kdb: use bool for binary state indicators defcmd_in_progress is the state trace for command group processing - within a command group or not - usable is an indicator if a command set is valid (allocated/non-empty) - so use a bool for those binary indication here. Signed-off-by: Nicholas Mc Guire Reviewed-by: Daniel Thompson Signed-off-by: Daniel Thompson --- kernel/debug/kdb/kdb_main.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel/debug/kdb') diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index d72b32c66f7d..82a3b32a7cfc 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -658,7 +658,7 @@ static void kdb_cmderror(int diag) */ struct defcmd_set { int count; - int usable; + bool usable; char *name; char *usage; char *help; @@ -666,7 +666,7 @@ struct defcmd_set { }; static struct defcmd_set *defcmd_set; static int defcmd_set_count; -static int defcmd_in_progress; +static bool defcmd_in_progress; /* Forward references */ static int kdb_exec_defcmd(int argc, const char **argv); @@ -676,9 +676,9 @@ static int kdb_defcmd2(const char *cmdstr, const char *argv0) struct defcmd_set *s = defcmd_set + defcmd_set_count - 1; char **save_command = s->command; if (strcmp(argv0, "endefcmd") == 0) { - defcmd_in_progress = 0; + defcmd_in_progress = false; if (!s->count) - s->usable = 0; + s->usable = false; if (s->usable) /* macros are always safe because when executed each * internal command re-enters kdb_parse() and is @@ -695,7 +695,7 @@ static int kdb_defcmd2(const char *cmdstr, const char *argv0) if (!s->command) { kdb_printf("Could not allocate new kdb_defcmd table for %s\n", cmdstr); - s->usable = 0; + s->usable = false; return KDB_NOTIMP; } memcpy(s->command, save_command, s->count * sizeof(*(s->command))); @@ -737,7 +737,7 @@ static int kdb_defcmd(int argc, const char **argv) defcmd_set_count * sizeof(*defcmd_set)); s = defcmd_set + defcmd_set_count; memset(s, 0, sizeof(*s)); - s->usable = 1; + s->usable = true; s->name = kdb_strdup(argv[1], GFP_KDB); if (!s->name) goto fail_name; @@ -756,7 +756,7 @@ static int kdb_defcmd(int argc, const char **argv) s->help[strlen(s->help)-1] = '\0'; } ++defcmd_set_count; - defcmd_in_progress = 1; + defcmd_in_progress = true; kfree(save_defcmd_set); return 0; fail_help: -- cgit v1.2.3