From 737a460f21febe551ff1d2299b63bae9b154078f Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Fri, 7 Mar 2008 16:34:16 -0600 Subject: [PATCH] kgdb: fix several kgdb regressions kgdb core fixes: - Check to see that mm->mmap_cache is not null before calling flush_cache_range(), else on arch=ARM it will cause a fatal fault. - Breakpoints should only be restored if they are in the BP_ACTIVE state. - Fix a typo in comments to "kgdb_register_io_module" x86 kgdb fixes: - Fix the x86 arch handler such that on a kill or detach that the appropriate cleanup on the single stepping flags gets run. - Add in the DIE_NMIWATCHDOG call for x86_64 - Touch the nmi watchdog before returning the system to normal operation after performing any kind of kgdb operation, else the possibility exists to trigger the watchdog. Signed-off-by: Jason Wessel Signed-off-by: Ingo Molnar --- arch/x86/kernel/kgdb.c | 4 ++++ arch/x86/kernel/traps_64.c | 7 ++++++- kernel/kgdb.c | 14 ++++++++------ 3 files changed, 18 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index 7d651adcb2..8c7e555f6d 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -370,6 +370,8 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, ptr = &remcomInBuffer[1]; if (kgdb_hex2long(&ptr, &addr)) linux_regs->ip = addr; + case 'D': + case 'k': newPC = linux_regs->ip; /* clear the trace bit */ @@ -480,6 +482,8 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd) if (kgdb_handle_exception(args->trapnr, args->signr, args->err, regs)) return NOTIFY_DONE; + /* Must touch watchdog before return to normal operation */ + touch_nmi_watchdog(); return NOTIFY_STOP; } diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c index 055b1650c6..4e073320e7 100644 --- a/arch/x86/kernel/traps_64.c +++ b/arch/x86/kernel/traps_64.c @@ -600,8 +600,13 @@ void die(const char * str, struct pt_regs * regs, long err) void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic) { - unsigned long flags = oops_begin(); + unsigned long flags; + + if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == + NOTIFY_STOP) + return; + flags = oops_begin(); /* * We are in trouble anyway, lets at least try * to get a message out. diff --git a/kernel/kgdb.c b/kernel/kgdb.c index 31425e0fbf..85b7e5b934 100644 --- a/kernel/kgdb.c +++ b/kernel/kgdb.c @@ -600,7 +600,7 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) if (!CACHE_FLUSH_IS_SAFE) return; - if (current->mm) { + if (current->mm && current->mm->mmap_cache) { flush_cache_range(current->mm->mmap_cache, addr, addr + BREAK_INSTR_SIZE); } else { @@ -729,14 +729,16 @@ int remove_all_break(void) /* Clear memory breakpoints. */ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) { - if (kgdb_break[i].state != BP_SET) - continue; + if (kgdb_break[i].state != BP_ACTIVE) + goto setundefined; addr = kgdb_break[i].bpt_addr; error = kgdb_arch_remove_breakpoint(addr, kgdb_break[i].saved_instr); if (error) - return error; - kgdb_break[i].state = BP_REMOVED; + printk(KERN_ERR "KGDB: breakpoint remove failed: %lx\n", + addr); +setundefined: + kgdb_break[i].state = BP_UNDEFINED; } /* Clear hardware breakpoints. */ @@ -1605,7 +1607,7 @@ static void kgdb_initial_breakpoint(void) } /** - * kkgdb_register_io_module - register KGDB IO module + * kgdb_register_io_module - register KGDB IO module * @new_kgdb_io_ops: the io ops vector * * Register it with the KGDB core. -- 2.39.5