From 2da2687b5116b0b791b14e56ff089c549986e48e Mon Sep 17 00:00:00 2001 From: Lukas Bulwahn Date: Mon, 25 Jan 2021 15:48:47 +0100 Subject: kgdb: rectify kernel-doc for kgdb_unregister_io_module() The command 'find ./kernel/debug/ | xargs ./scripts/kernel-doc -none' reported a typo in the kernel-doc of kgdb_unregister_io_module(). Rectify the kernel-doc, such that no issues remain for ./kernel/debug/. Signed-off-by: Lukas Bulwahn Link: https://lore.kernel.org/r/20210125144847.21896-1-lukas.bulwahn@gmail.com Signed-off-by: Daniel Thompson --- kernel/debug/debug_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index af6e8b4fb359..7f22c1c0ffe8 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -1166,7 +1166,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops) EXPORT_SYMBOL_GPL(kgdb_register_io_module); /** - * kkgdb_unregister_io_module - unregister KGDB IO module + * kgdb_unregister_io_module - unregister KGDB IO module * @old_dbg_io_ops: the io ops vector * * Unregister it with the KGDB core. -- cgit v1.2.3-59-g8ed1b From f11e2bc682cc197e33bfd118178cadb61326dc0e Mon Sep 17 00:00:00 2001 From: Daniel Thompson Date: Wed, 10 Feb 2021 14:25:25 +0000 Subject: kgdb: Remove kgdb_schedule_breakpoint() To the very best of my knowledge there has never been any in-tree code that calls this function. It exists largely to support an out-of-tree driver that provides kgdb-over-ethernet using the netpoll API. kgdboe has been out-of-tree for more than 10 years and I don't recall any serious attempt to upstream it at any point in the last five. At this stage it looks better to stop carrying this code in the kernel and integrate the code into the out-of-tree driver instead. The long term trajectory for the kernel looks likely to include effort to remove or reduce the use of tasklets (something that has also been true for the last 10 years). Thus the main real reason for this patch is to make explicit that the in-tree kgdb features do not require tasklets. Signed-off-by: Daniel Thompson Link: https://lore.kernel.org/r/20210210142525.2876648-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson Acked-by: Davidlohr Bueso Acked-by: Jason Wessel --- include/linux/kgdb.h | 1 - kernel/debug/debug_core.c | 26 -------------------------- 2 files changed, 27 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 0d6cf64c8bb1..0444b44bd156 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -325,7 +325,6 @@ extern char *kgdb_mem2hex(char *mem, char *buf, int count); extern int kgdb_hex2mem(char *buf, char *mem, int count); extern int kgdb_isremovedbreak(unsigned long addr); -extern void kgdb_schedule_breakpoint(void); extern int kgdb_has_hit_break(unsigned long addr); extern int diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 7f22c1c0ffe8..b636d517c02c 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -119,7 +119,6 @@ static DEFINE_RAW_SPINLOCK(dbg_slave_lock); */ static atomic_t masters_in_kgdb; static atomic_t slaves_in_kgdb; -static atomic_t kgdb_break_tasklet_var; atomic_t kgdb_setting_breakpoint; struct task_struct *kgdb_usethread; @@ -1084,31 +1083,6 @@ static void kgdb_unregister_callbacks(void) } } -/* - * There are times a tasklet needs to be used vs a compiled in - * break point so as to cause an exception outside a kgdb I/O module, - * such as is the case with kgdboe, where calling a breakpoint in the - * I/O driver itself would be fatal. - */ -static void kgdb_tasklet_bpt(unsigned long ing) -{ - kgdb_breakpoint(); - atomic_set(&kgdb_break_tasklet_var, 0); -} - -static DECLARE_TASKLET_OLD(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt); - -void kgdb_schedule_breakpoint(void) -{ - if (atomic_read(&kgdb_break_tasklet_var) || - atomic_read(&kgdb_active) != -1 || - atomic_read(&kgdb_setting_breakpoint)) - return; - atomic_inc(&kgdb_break_tasklet_var); - tasklet_schedule(&kgdb_tasklet_breakpoint); -} -EXPORT_SYMBOL_GPL(kgdb_schedule_breakpoint); - /** * kgdb_register_io_module - register KGDB IO module * @new_dbg_io_ops: the io ops vector -- cgit v1.2.3-59-g8ed1b From d54ce6158e354f5358a547b96299ecd7f3725393 Mon Sep 17 00:00:00 2001 From: Sumit Garg Date: Thu, 25 Feb 2021 17:22:38 -0800 Subject: kgdb: fix to kill breakpoints on initmem after boot Currently breakpoints in kernel .init.text section are not handled correctly while allowing to remove them even after corresponding pages have been freed. Fix it via killing .init.text section breakpoints just prior to initmem pages being freed. Doug: "HW breakpoints aren't handled by this patch but it's probably not such a big deal". Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org Signed-off-by: Sumit Garg Suggested-by: Doug Anderson Acked-by: Doug Anderson Acked-by: Daniel Thompson Tested-by: Daniel Thompson Cc: Masami Hiramatsu Cc: Steven Rostedt (VMware) Cc: Jason Wessel Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kgdb.h | 2 ++ init/main.c | 1 + kernel/debug/debug_core.c | 11 +++++++++++ 3 files changed, 14 insertions(+) (limited to 'kernel/debug/debug_core.c') diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 0444b44bd156..392a3670944c 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -359,9 +359,11 @@ extern atomic_t kgdb_active; extern bool dbg_is_early; extern void __init dbg_late_init(void); extern void kgdb_panic(const char *msg); +extern void kgdb_free_init_mem(void); #else /* ! CONFIG_KGDB */ #define in_dbg_master() (0) #define dbg_late_init() static inline void kgdb_panic(const char *msg) {} +static inline void kgdb_free_init_mem(void) { } #endif /* ! CONFIG_KGDB */ #endif /* _KGDB_H_ */ diff --git a/init/main.c b/init/main.c index 3648c9f94882..53b278845b88 100644 --- a/init/main.c +++ b/init/main.c @@ -1426,6 +1426,7 @@ static int __ref kernel_init(void *unused) async_synchronize_full(); kprobe_free_init_mem(); ftrace_free_init_mem(); + kgdb_free_init_mem(); free_initmem(); mark_readonly(); diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index b636d517c02c..4708aec492df 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -455,6 +455,17 @@ setundefined: return 0; } +void kgdb_free_init_mem(void) +{ + int i; + + /* Clear init memory breakpoints. */ + for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { + if (init_section_contains((void *)kgdb_break[i].bpt_addr, 0)) + kgdb_break[i].state = BP_UNDEFINED; + } +} + #ifdef CONFIG_KGDB_KDB void kdb_dump_stack_on_cpu(int cpu) { -- cgit v1.2.3-59-g8ed1b