Re: [PATCH 6/7] powerpc/traps: Print signal name for unhandled signals
Hi, Christophe.
On Wed, Jul 25, 2018 at 05:49:27PM +0200, LEROY Christophe wrote:
> Murilo Opsfelder Araujo a écrit :
>
> > This adds a human-readable name in the unhandled signal message.
> >
> > Before this patch, a page fault looked like:
> >
> > Jul 11 16:04:11 localhost kernel: pandafault[6303]: unhandled signal
> > 11 at 17d0 nip 161c lr 7fff93c55100 code 2
> > in pandafault[1000+1]
> >
> > After this patch, a page fault looks like:
> >
> > Jul 11 18:14:48 localhost kernel: pandafault[6352]: segfault (11) at
> > 00013a2a09f8 nip 00013a2a086c lr 7fffb63e5100 code 2 in
> > pandafault[13a2a+1]
> >
> > Signed-off-by: Murilo Opsfelder Araujo
> > ---
> > arch/powerpc/kernel/traps.c | 43 +
> > 1 file changed, 39 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
> > index e6c43ef9fb50..e55ee639d010 100644
> > --- a/arch/powerpc/kernel/traps.c
> > +++ b/arch/powerpc/kernel/traps.c
> > @@ -96,6 +96,41 @@ EXPORT_SYMBOL(__debugger_fault_handler);
> > #define TM_DEBUG(x...) do { } while(0)
> > #endif
> >
> > +static const char *signames[SIGRTMIN + 1] = {
> > + "UNKNOWN",
> > + "SIGHUP", // 1
> > + "SIGINT", // 2
> > + "SIGQUIT", // 3
> > + "SIGILL", // 4
> > + "unhandled trap", // 5 = SIGTRAP
> > + "SIGABRT", // 6 = SIGIOT
> > + "bus error",// 7 = SIGBUS
> > + "floating point exception", // 8 = SIGFPE
> > + "illegal instruction", // 9 = SIGILL
> > + "SIGUSR1", // 10
> > + "segfault", // 11 = SIGSEGV
> > + "SIGUSR2", // 12
> > + "SIGPIPE", // 13
> > + "SIGALRM", // 14
> > + "SIGTERM", // 15
> > + "SIGSTKFLT",// 16
> > + "SIGCHLD", // 17
> > + "SIGCONT", // 18
> > + "SIGSTOP", // 19
> > + "SIGTSTP", // 20
> > + "SIGTTIN", // 21
> > + "SIGTTOU", // 22
> > + "SIGURG", // 23
> > + "SIGXCPU", // 24
> > + "SIGXFSZ", // 25
> > + "SIGVTALRM",// 26
> > + "SIGPROF", // 27
> > + "SIGWINCH", // 28
> > + "SIGIO",// 29 = SIGPOLL = SIGLOST
> > + "SIGPWR", // 30
> > + "SIGSYS", // 31 = SIGUNUSED
> > +};
> > +
> > /*
> > * Trap & Exception support
> > */
> > @@ -314,10 +349,10 @@ static void show_signal_msg(int signr, struct
> > pt_regs *regs, int code,
> > if (!unhandled_signal(current, signr))
> > return;
> >
> > - pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
> > - " nip "REG_FMT" lr "REG_FMT" code %x",
> > - current->comm, current->pid, signr, addr,
> > - regs->nip, regs->link, code);
> > + pr_info("%s[%d]: %s (%d) at "REG_FMT" nip "REG_FMT \
> > + " lr "REG_FMT" code %x",
> > + current->comm, current->pid, signames[signr],
> > + signr, addr, regs->nip, regs->link, code);
>
> Are we sure that signr is always within the limits of the table ?
Looking at the code, we only pass the following signals:
SIGBUS
SIGFPE
SIGILL
SIGSEGV
SIGTRAP
All of them are within the limits of the table. We've added other
signals for completeness.
Cheers
Murilo
Re: [PATCH 6/7] powerpc/traps: Print signal name for unhandled signals
Hi, Gustavo. On Wed, Jul 25, 2018 at 12:19:00PM -0300, Gustavo Romero wrote: > Hi Murilo, > > LGTM. > > Just a comment: > > On 07/24/2018 04:27 PM, Murilo Opsfelder Araujo wrote: > > This adds a human-readable name in the unhandled signal message. > > > > Before this patch, a page fault looked like: > > > > Jul 11 16:04:11 localhost kernel: pandafault[6303]: unhandled signal > > 11 at 17d0 nip 161c lr 7fff93c55100 code 2 in > > pandafault[1000+1] > > > > After this patch, a page fault looks like: > > > > Jul 11 18:14:48 localhost kernel: pandafault[6352]: segfault (11) at > > 00013a2a09f8 nip 00013a2a086c lr 7fffb63e5100 code 2 in > > pandafault[13a2a+1] > > I _really_ don't want to bikeshed here, but I vouch for keeping the > "unhandled" word before the signal name, like: > > [...] pandafault[6352]: unhandled segfault (11) at 00013a2a09f8 nip [...] > > because the issue reported here is really that we got a segfault _and_ > there was no handler to catch it. Either way works for me. > But feel free to wait for additional comments to decide it. Sure. I intend to wait a couple of weeks to respin the series based on community feedback. Cheers Murilo
Re: [PATCH 6/7] powerpc/traps: Print signal name for unhandled signals
Murilo Opsfelder Araujo a écrit :
This adds a human-readable name in the unhandled signal message.
Before this patch, a page fault looked like:
Jul 11 16:04:11 localhost kernel: pandafault[6303]: unhandled
signal 11 at 17d0 nip 161c lr
7fff93c55100 code 2 in pandafault[1000+1]
After this patch, a page fault looks like:
Jul 11 18:14:48 localhost kernel: pandafault[6352]: segfault
(11) at 00013a2a09f8 nip 00013a2a086c lr 7fffb63e5100
code 2 in pandafault[13a2a+1]
Signed-off-by: Murilo Opsfelder Araujo
---
arch/powerpc/kernel/traps.c | 43 +
1 file changed, 39 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index e6c43ef9fb50..e55ee639d010 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -96,6 +96,41 @@ EXPORT_SYMBOL(__debugger_fault_handler);
#define TM_DEBUG(x...) do { } while(0)
#endif
+static const char *signames[SIGRTMIN + 1] = {
+ "UNKNOWN",
+ "SIGHUP", // 1
+ "SIGINT", // 2
+ "SIGQUIT",// 3
+ "SIGILL", // 4
+ "unhandled trap", // 5 = SIGTRAP
+ "SIGABRT",// 6 = SIGIOT
+ "bus error", // 7 = SIGBUS
+ "floating point exception", // 8 = SIGFPE
+ "illegal instruction",// 9 = SIGILL
+ "SIGUSR1",// 10
+ "segfault", // 11 = SIGSEGV
+ "SIGUSR2",// 12
+ "SIGPIPE",// 13
+ "SIGALRM",// 14
+ "SIGTERM",// 15
+ "SIGSTKFLT", // 16
+ "SIGCHLD",// 17
+ "SIGCONT",// 18
+ "SIGSTOP",// 19
+ "SIGTSTP",// 20
+ "SIGTTIN",// 21
+ "SIGTTOU",// 22
+ "SIGURG", // 23
+ "SIGXCPU",// 24
+ "SIGXFSZ",// 25
+ "SIGVTALRM", // 26
+ "SIGPROF",// 27
+ "SIGWINCH", // 28
+ "SIGIO", // 29 = SIGPOLL = SIGLOST
+ "SIGPWR", // 30
+ "SIGSYS", // 31 = SIGUNUSED
+};
+
/*
* Trap & Exception support
*/
@@ -314,10 +349,10 @@ static void show_signal_msg(int signr, struct
pt_regs *regs, int code,
if (!unhandled_signal(current, signr))
return;
- pr_info("%s[%d]: unhandled signal %d at "REG_FMT \
- " nip "REG_FMT" lr "REG_FMT" code %x",
- current->comm, current->pid, signr, addr,
- regs->nip, regs->link, code);
+ pr_info("%s[%d]: %s (%d) at "REG_FMT" nip "REG_FMT \
+ " lr "REG_FMT" code %x",
+ current->comm, current->pid, signames[signr],
+ signr, addr, regs->nip, regs->link, code);
Are we sure that signr is always within the limits of the table ?
Christophe
print_vma_addr(KERN_CONT " in ", regs->nip);
--
2.17.1
Re: [PATCH 6/7] powerpc/traps: Print signal name for unhandled signals
Hi Murilo, LGTM. Just a comment: On 07/24/2018 04:27 PM, Murilo Opsfelder Araujo wrote: This adds a human-readable name in the unhandled signal message. Before this patch, a page fault looked like: Jul 11 16:04:11 localhost kernel: pandafault[6303]: unhandled signal 11 at 17d0 nip 161c lr 7fff93c55100 code 2 in pandafault[1000+1] After this patch, a page fault looks like: Jul 11 18:14:48 localhost kernel: pandafault[6352]: segfault (11) at 00013a2a09f8 nip 00013a2a086c lr 7fffb63e5100 code 2 in pandafault[13a2a+1] I _really_ don't want to bikeshed here, but I vouch for keeping the "unhandled" word before the signal name, like: [...] pandafault[6352]: unhandled segfault (11) at 00013a2a09f8 nip [...] because the issue reported here is really that we got a segfault _and_ there was no handler to catch it. But feel free to wait for additional comments to decide it. Cheers, Gustavo
