Message ID | 20190110115737.30931-1-mpe@ellerman.id.au (mailing list archive) |
---|---|
State | Accepted |
Commit | 782274434d6f2e8aa8c573cb24fef94a164f2ce0 |
Headers | show |
Series | [v2,1/3] powerpc: Stop using pr_cont() in __die() | expand |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 2 warnings, 0 checks, 32 lines checked |
Le 10/01/2019 à 12:57, Michael Ellerman a écrit : > Using pr_cont() risks having our output interleaved with other output > from other CPUs. Instead print everything in a single printk() call. > > Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > arch/powerpc/kernel/traps.c | 26 ++++++++------------------ > 1 file changed, 8 insertions(+), 18 deletions(-) > > v2: Use a single printk with (mostly) compile time checks rather than > constructing the string with seq_buf. > > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index 64936b60d521..164fc92895be 100644 > --- a/arch/powerpc/kernel/traps.c > +++ b/arch/powerpc/kernel/traps.c > @@ -257,24 +257,14 @@ static int __die(const char *str, struct pt_regs *regs, long err) > { > printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); Maybe this printk() should also be merge with the following to further limit risks of interleaving ? Christophe > > - if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) > - printk("LE "); > - else > - printk("BE "); > - > - if (IS_ENABLED(CONFIG_PREEMPT)) > - pr_cont("PREEMPT "); > - > - if (IS_ENABLED(CONFIG_SMP)) > - pr_cont("SMP NR_CPUS=%d ", NR_CPUS); > - > - if (debug_pagealloc_enabled()) > - pr_cont("DEBUG_PAGEALLOC "); > - > - if (IS_ENABLED(CONFIG_NUMA)) > - pr_cont("NUMA "); > - > - pr_cont("%s\n", ppc_md.name ? ppc_md.name : ""); > + printk("%s %s%s%s%s%s %s\n", > + IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", > + IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", > + IS_ENABLED(CONFIG_SMP) ? " SMP" : "", > + IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", > + debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", > + IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "", > + ppc_md.name ? ppc_md.name : ""); > > if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) > return 1; >
Christophe Leroy <christophe.leroy@c-s.fr> writes: > Le 10/01/2019 à 12:57, Michael Ellerman a écrit : >> Using pr_cont() risks having our output interleaved with other output >> from other CPUs. Instead print everything in a single printk() call. >> >> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> > > Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> > >> --- >> arch/powerpc/kernel/traps.c | 26 ++++++++------------------ >> 1 file changed, 8 insertions(+), 18 deletions(-) >> >> v2: Use a single printk with (mostly) compile time checks rather than >> constructing the string with seq_buf. >> >> diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c >> index 64936b60d521..164fc92895be 100644 >> --- a/arch/powerpc/kernel/traps.c >> +++ b/arch/powerpc/kernel/traps.c >> @@ -257,24 +257,14 @@ static int __die(const char *str, struct pt_regs *regs, long err) >> { >> printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); > > Maybe this printk() should also be merge with the following to further > limit risks of interleaving ? Possibly yeah. Though I was comparing it to other arches and I think we could improve the info on that line. So I'll leave it for now. cheers
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 64936b60d521..164fc92895be 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -257,24 +257,14 @@ static int __die(const char *str, struct pt_regs *regs, long err) { printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter); - if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) - printk("LE "); - else - printk("BE "); - - if (IS_ENABLED(CONFIG_PREEMPT)) - pr_cont("PREEMPT "); - - if (IS_ENABLED(CONFIG_SMP)) - pr_cont("SMP NR_CPUS=%d ", NR_CPUS); - - if (debug_pagealloc_enabled()) - pr_cont("DEBUG_PAGEALLOC "); - - if (IS_ENABLED(CONFIG_NUMA)) - pr_cont("NUMA "); - - pr_cont("%s\n", ppc_md.name ? ppc_md.name : ""); + printk("%s %s%s%s%s%s %s\n", + IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE", + IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "", + IS_ENABLED(CONFIG_SMP) ? " SMP" : "", + IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "", + debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "", + IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "", + ppc_md.name ? ppc_md.name : ""); if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) return 1;
Using pr_cont() risks having our output interleaved with other output from other CPUs. Instead print everything in a single printk() call. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/kernel/traps.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) v2: Use a single printk with (mostly) compile time checks rather than constructing the string with seq_buf.