diff options
| author | Anton Vorontsov <anton.vorontsov@linaro.org> | 2012-09-24 14:27:50 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-26 13:42:25 -0700 |
| commit | 5a14fead07bcf4e0acc877a8d9e1d1f40a441153 (patch) | |
| tree | 7fd90cf9cdd0b734f013df6bb86f34fdd80c5732 /kernel/debug | |
| parent | c5dd553b9fd069892c9e2de734f4f604e280fa7a (diff) | |
| download | lwn-5a14fead07bcf4e0acc877a8d9e1d1f40a441153.tar.gz lwn-5a14fead07bcf4e0acc877a8d9e1d1f40a441153.zip | |
kernel/debug: Mask KGDB NMI upon entry
The new arch callback should manage NMIs that usually cause KGDB to
enter. That is, not all NMIs should be enabled/disabled, but only
those that issue kgdb_handle_exception().
We must mask it as serial-line interrupt can be used as an NMI, so
if the original KGDB-entry cause was say a breakpoint, then every
input to KDB console will cause KGDB to reenter, which we don't want.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/debug')
| -rw-r--r-- | kernel/debug/debug_core.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 0557f24c6bca..17e073c309e6 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -672,6 +672,10 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) { struct kgdb_state kgdb_var; struct kgdb_state *ks = &kgdb_var; + int ret = 0; + + if (arch_kgdb_ops.enable_nmi) + arch_kgdb_ops.enable_nmi(0); ks->cpu = raw_smp_processor_id(); ks->ex_vector = evector; @@ -681,11 +685,15 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs) ks->linux_regs = regs; if (kgdb_reenter_check(ks)) - return 0; /* Ouch, double exception ! */ + goto out; /* Ouch, double exception ! */ if (kgdb_info[ks->cpu].enter_kgdb != 0) - return 0; + goto out; - return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); + ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER); +out: + if (arch_kgdb_ops.enable_nmi) + arch_kgdb_ops.enable_nmi(1); + return ret; } int kgdb_nmicallback(int cpu, void *regs) |