From a1465d2f396e416a0049332b20fca5977384b9f5 Mon Sep 17 00:00:00 2001 From: Daniel Thompson Date: Tue, 11 Nov 2014 09:31:53 -0600 Subject: kgdb: timeout if secondary CPUs ignore the roundup Currently if an active CPU fails to respond to a roundup request the CPU that requested the roundup will become stuck. This needlessly reduces the robustness of the debugger. This patch introduces a timeout allowing the system state to be examined even when the system contains unresponsive processors. It also modifies kdb's cpu command to make it censor attempts to switch to unresponsive processors and to report their state as (D)ead. Signed-off-by: Daniel Thompson Cc: Jason Wessel Signed-off-by: Andrew Morton Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 1adf62b39b96..acd749736822 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -471,6 +471,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs, int cpu; int trace_on = 0; int online_cpus = num_online_cpus(); + u64 time_left; kgdb_info[ks->cpu].enter_kgdb++; kgdb_info[ks->cpu].exception_state |= exception_state; @@ -595,9 +596,13 @@ return_normal: /* * Wait for the other CPUs to be notified and be waiting for us: */ - while (kgdb_do_roundup && (atomic_read(&masters_in_kgdb) + - atomic_read(&slaves_in_kgdb)) != online_cpus) + time_left = loops_per_jiffy * HZ; + while (kgdb_do_roundup && --time_left && + (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) != + online_cpus) cpu_relax(); + if (!time_left) + pr_crit("KGDB: Timed out waiting for secondary CPUs.\n"); /* * At this point the primary processor is completely -- cgit v1.2.3-71-gd317 From 0f16996cf2ed7c368dd95b4c517ce572b96a10f5 Mon Sep 17 00:00:00 2001 From: Fabian Frederick Date: Thu, 12 Jun 2014 21:30:11 +0200 Subject: kernel/debug/debug_core.c: Logging clean-up -Convert printk( to pr_foo() -Add pr_fmt -Coalesce formats Cc: Jason Wessel Cc: Andrew Morton Cc: Joe Perches Signed-off-by: Fabian Frederick Signed-off-by: Jason Wessel --- kernel/debug/debug_core.c | 43 +++++++++++++++++++++---------------------- 1 file changed, 21 insertions(+), 22 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index acd749736822..07ce18ca71e0 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -27,6 +27,9 @@ * version 2. This program is licensed "as is" without any warranty of any * kind, whether express or implied. */ + +#define pr_fmt(fmt) "KGDB: " fmt + #include #include #include @@ -196,8 +199,8 @@ int __weak kgdb_validate_break_address(unsigned long addr) return err; err = kgdb_arch_remove_breakpoint(&tmp); if (err) - printk(KERN_ERR "KGDB: Critical breakpoint error, kernel " - "memory destroyed at: %lx", addr); + pr_err("Critical breakpoint error, kernel memory destroyed at: %lx\n", + addr); return err; } @@ -256,8 +259,8 @@ int dbg_activate_sw_breakpoints(void) error = kgdb_arch_set_breakpoint(&kgdb_break[i]); if (error) { ret = error; - printk(KERN_INFO "KGDB: BP install failed: %lx", - kgdb_break[i].bpt_addr); + pr_info("BP install failed: %lx\n", + kgdb_break[i].bpt_addr); continue; } @@ -319,8 +322,8 @@ int dbg_deactivate_sw_breakpoints(void) continue; error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) { - printk(KERN_INFO "KGDB: BP remove failed: %lx\n", - kgdb_break[i].bpt_addr); + pr_info("BP remove failed: %lx\n", + kgdb_break[i].bpt_addr); ret = error; } @@ -367,7 +370,7 @@ int dbg_remove_all_break(void) goto setundefined; error = kgdb_arch_remove_breakpoint(&kgdb_break[i]); if (error) - printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", + pr_err("breakpoint remove failed: %lx\n", kgdb_break[i].bpt_addr); setundefined: kgdb_break[i].state = BP_UNDEFINED; @@ -400,9 +403,9 @@ static int kgdb_io_ready(int print_wait) if (print_wait) { #ifdef CONFIG_KGDB_KDB if (!dbg_kdb_mode) - printk(KERN_CRIT "KGDB: waiting... or $3#33 for KDB\n"); + pr_crit("waiting... or $3#33 for KDB\n"); #else - printk(KERN_CRIT "KGDB: Waiting for remote debugger\n"); + pr_crit("Waiting for remote debugger\n"); #endif } return 1; @@ -430,8 +433,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks) exception_level = 0; kgdb_skipexception(ks->ex_vector, ks->linux_regs); dbg_activate_sw_breakpoints(); - printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n", - addr); + pr_crit("re-enter error: breakpoint removed %lx\n", addr); WARN_ON_ONCE(1); return 1; @@ -444,7 +446,7 @@ static int kgdb_reenter_check(struct kgdb_state *ks) panic("Recursive entry to debugger"); } - printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n"); + pr_crit("re-enter exception: ALL breakpoints killed\n"); #ifdef CONFIG_KGDB_KDB /* Allow kdb to debug itself one level */ return 0; @@ -800,15 +802,15 @@ static struct console kgdbcons = { static void sysrq_handle_dbg(int key) { if (!dbg_io_ops) { - printk(KERN_CRIT "ERROR: No KGDB I/O module available\n"); + pr_crit("ERROR: No KGDB I/O module available\n"); return; } if (!kgdb_connected) { #ifdef CONFIG_KGDB_KDB if (!dbg_kdb_mode) - printk(KERN_CRIT "KGDB or $3#33 for KDB\n"); + pr_crit("KGDB or $3#33 for KDB\n"); #else - printk(KERN_CRIT "Entering KGDB\n"); + pr_crit("Entering KGDB\n"); #endif } @@ -950,7 +952,7 @@ static void kgdb_initial_breakpoint(void) { kgdb_break_asap = 0; - printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n"); + pr_crit("Waiting for connection from remote gdb...\n"); kgdb_breakpoint(); } @@ -969,8 +971,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops) if (dbg_io_ops) { spin_unlock(&kgdb_registration_lock); - printk(KERN_ERR "kgdb: Another I/O driver is already " - "registered with KGDB.\n"); + pr_err("Another I/O driver is already registered with KGDB\n"); return -EBUSY; } @@ -986,8 +987,7 @@ int kgdb_register_io_module(struct kgdb_io *new_dbg_io_ops) spin_unlock(&kgdb_registration_lock); - printk(KERN_INFO "kgdb: Registered I/O driver %s.\n", - new_dbg_io_ops->name); + pr_info("Registered I/O driver %s\n", new_dbg_io_ops->name); /* Arm KGDB now. */ kgdb_register_callbacks(); @@ -1022,8 +1022,7 @@ void kgdb_unregister_io_module(struct kgdb_io *old_dbg_io_ops) spin_unlock(&kgdb_registration_lock); - printk(KERN_INFO - "kgdb: Unregistered I/O driver %s, debugger disabled.\n", + pr_info("Unregistered I/O driver %s, debugger disabled\n", old_dbg_io_ops->name); } EXPORT_SYMBOL_GPL(kgdb_unregister_io_module); -- cgit v1.2.3-71-gd317