Message ID | 20161118113926.31350-1-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
On Fri, 18 Nov 2016 17:09:26 +0530 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote: > ... rather than through notify_die(), to reduce path taken for handling > kprobes. Similar to commit 6f6343f53d13 ("kprobes/x86: Call exception > handlers directly from do_int3/do_debug"). > > While at it, rename post_kprobe_handler() to kprobe_post_handler() for > more uniform naming. Looks good to me. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Thanks! > > Reported-by: Masami Hiramatsu <mhiramat@kernel.org> > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/kprobes.h | 2 ++ > arch/powerpc/kernel/kprobes.c | 29 +++++++---------------------- > arch/powerpc/kernel/traps.c | 20 ++++++++++++++++++++ > 3 files changed, 29 insertions(+), 22 deletions(-) > > diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h > index 2c9759bd..47c60d0 100644 > --- a/arch/powerpc/include/asm/kprobes.h > +++ b/arch/powerpc/include/asm/kprobes.h > @@ -126,6 +126,8 @@ struct kprobe_ctlblk { > > extern int kprobe_exceptions_notify(struct notifier_block *self, > unsigned long val, void *data); > +extern int kprobe_handler(struct pt_regs *regs); > +extern int kprobe_post_handler(struct pt_regs *regs); > extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); > #endif /* __KERNEL__ */ > #endif /* _ASM_POWERPC_KPROBES_H */ > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > index 9479d8e..ad108b8 100644 > --- a/arch/powerpc/kernel/kprobes.c > +++ b/arch/powerpc/kernel/kprobes.c > @@ -140,13 +140,16 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, > regs->link = (unsigned long)kretprobe_trampoline; > } > > -static int __kprobes kprobe_handler(struct pt_regs *regs) > +int __kprobes kprobe_handler(struct pt_regs *regs) > { > struct kprobe *p; > int ret = 0; > unsigned int *addr = (unsigned int *)regs->nip; > struct kprobe_ctlblk *kcb; > > + if (user_mode(regs)) > + return 0; > + > /* > * We don't want to be preempted for the entire > * duration of kprobe processing > @@ -359,12 +362,12 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, > * single-stepped a copy of the instruction. The address of this > * copy is p->ainsn.insn. > */ > -static int __kprobes post_kprobe_handler(struct pt_regs *regs) > +int __kprobes kprobe_post_handler(struct pt_regs *regs) > { > struct kprobe *cur = kprobe_running(); > struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); > > - if (!cur) > + if (!cur || user_mode(regs)) > return 0; > > /* make sure we got here for instruction we have a kprobe on */ > @@ -470,25 +473,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) > int __kprobes kprobe_exceptions_notify(struct notifier_block *self, > unsigned long val, void *data) > { > - struct die_args *args = (struct die_args *)data; > - int ret = NOTIFY_DONE; > - > - if (args->regs && user_mode(args->regs)) > - return ret; > - > - switch (val) { > - case DIE_BPT: > - if (kprobe_handler(args->regs)) > - ret = NOTIFY_STOP; > - break; > - case DIE_SSTEP: > - if (post_kprobe_handler(args->regs)) > - ret = NOTIFY_STOP; > - break; > - default: > - break; > - } > - return ret; > + return NOTIFY_DONE; > } > > unsigned long arch_deref_entry_point(void *entry) > diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c > index 91d278c..dbcdf48 100644 > --- a/arch/powerpc/kernel/traps.c > +++ b/arch/powerpc/kernel/traps.c > @@ -824,6 +824,11 @@ void single_step_exception(struct pt_regs *regs) > > clear_single_step(regs); > > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif > + > if (notify_die(DIE_SSTEP, "single_step", regs, 5, > 5, SIGTRAP) == NOTIFY_STOP) > goto bail; > @@ -1177,6 +1182,11 @@ void program_check_exception(struct pt_regs *regs) > if (debugger_bpt(regs)) > goto bail; > > +#ifdef CONFIG_KPROBES > + if (kprobe_handler(regs)) > + goto bail; > +#endif > + > /* trap exception */ > if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) > == NOTIFY_STOP) > @@ -1745,6 +1755,11 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status) > return; > } > > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif > + > if (notify_die(DIE_SSTEP, "block_step", regs, 5, > 5, SIGTRAP) == NOTIFY_STOP) { > return; > @@ -1759,6 +1774,11 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status) > /* Clear the instruction completion event */ > mtspr(SPRN_DBSR, DBSR_IC); > > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif > + > if (notify_die(DIE_SSTEP, "single_step", regs, 5, > 5, SIGTRAP) == NOTIFY_STOP) { > return; > -- > 2.10.2 >
On Fri, Nov 18, 2016 at 05:09:26PM +0530, Naveen N. Rao wrote: > ... rather than through notify_die(), to reduce path taken for handling > kprobes. Similar to commit 6f6343f53d13 ("kprobes/x86: Call exception > handlers directly from do_int3/do_debug"). > > While at it, rename post_kprobe_handler() to kprobe_post_handler() for > more uniform naming. > > Reported-by: Masami Hiramatsu <mhiramat@kernel.org> > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> writes: > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif ... > +#ifdef CONFIG_KPROBES > + if (kprobe_handler(regs)) > + goto bail; > +#endif ... > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif ... > +#ifdef CONFIG_KPROBES > + if (kprobe_post_handler(regs)) > + return; > +#endif > + Sorry too many ifdefs. Can you please add empty static inline versions for CONFIG_KPROBES=n that always return false. The compiler will be smart enough to elide them entirely. cheers
diff --git a/arch/powerpc/include/asm/kprobes.h b/arch/powerpc/include/asm/kprobes.h index 2c9759bd..47c60d0 100644 --- a/arch/powerpc/include/asm/kprobes.h +++ b/arch/powerpc/include/asm/kprobes.h @@ -126,6 +126,8 @@ struct kprobe_ctlblk { extern int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); +extern int kprobe_handler(struct pt_regs *regs); +extern int kprobe_post_handler(struct pt_regs *regs); extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr); #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_KPROBES_H */ diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 9479d8e..ad108b8 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -140,13 +140,16 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, regs->link = (unsigned long)kretprobe_trampoline; } -static int __kprobes kprobe_handler(struct pt_regs *regs) +int __kprobes kprobe_handler(struct pt_regs *regs) { struct kprobe *p; int ret = 0; unsigned int *addr = (unsigned int *)regs->nip; struct kprobe_ctlblk *kcb; + if (user_mode(regs)) + return 0; + /* * We don't want to be preempted for the entire * duration of kprobe processing @@ -359,12 +362,12 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, * single-stepped a copy of the instruction. The address of this * copy is p->ainsn.insn. */ -static int __kprobes post_kprobe_handler(struct pt_regs *regs) +int __kprobes kprobe_post_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (!cur) + if (!cur || user_mode(regs)) return 0; /* make sure we got here for instruction we have a kprobe on */ @@ -470,25 +473,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) int __kprobes kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { - struct die_args *args = (struct die_args *)data; - int ret = NOTIFY_DONE; - - if (args->regs && user_mode(args->regs)) - return ret; - - switch (val) { - case DIE_BPT: - if (kprobe_handler(args->regs)) - ret = NOTIFY_STOP; - break; - case DIE_SSTEP: - if (post_kprobe_handler(args->regs)) - ret = NOTIFY_STOP; - break; - default: - break; - } - return ret; + return NOTIFY_DONE; } unsigned long arch_deref_entry_point(void *entry) diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 91d278c..dbcdf48 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -824,6 +824,11 @@ void single_step_exception(struct pt_regs *regs) clear_single_step(regs); +#ifdef CONFIG_KPROBES + if (kprobe_post_handler(regs)) + return; +#endif + if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) goto bail; @@ -1177,6 +1182,11 @@ void program_check_exception(struct pt_regs *regs) if (debugger_bpt(regs)) goto bail; +#ifdef CONFIG_KPROBES + if (kprobe_handler(regs)) + goto bail; +#endif + /* trap exception */ if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) @@ -1745,6 +1755,11 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status) return; } +#ifdef CONFIG_KPROBES + if (kprobe_post_handler(regs)) + return; +#endif + if (notify_die(DIE_SSTEP, "block_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return; @@ -1759,6 +1774,11 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status) /* Clear the instruction completion event */ mtspr(SPRN_DBSR, DBSR_IC); +#ifdef CONFIG_KPROBES + if (kprobe_post_handler(regs)) + return; +#endif + if (notify_die(DIE_SSTEP, "single_step", regs, 5, 5, SIGTRAP) == NOTIFY_STOP) { return;
... rather than through notify_die(), to reduce path taken for handling kprobes. Similar to commit 6f6343f53d13 ("kprobes/x86: Call exception handlers directly from do_int3/do_debug"). While at it, rename post_kprobe_handler() to kprobe_post_handler() for more uniform naming. Reported-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/include/asm/kprobes.h | 2 ++ arch/powerpc/kernel/kprobes.c | 29 +++++++---------------------- arch/powerpc/kernel/traps.c | 20 ++++++++++++++++++++ 3 files changed, 29 insertions(+), 22 deletions(-)