| Message ID | 20210419002919.1a0a539d@xhacker (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: kprobes: Remove redundant kprobe_step_ctx | expand |
On Mon, 19 Apr 2021 00:29:19 +0800 Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote: > From: Jisheng Zhang <jszhang@kernel.org> > > Inspired by commit ba090f9cafd5 ("arm64: kprobes: Remove redundant > kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx > are redundant because those can be replaced by KPROBE_HIT_SS and > &cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) > respectively. > > Remove the kprobe_step_ctx to simplify the code. Hi all, This patch can still be applied to 5.13-rc1, could you please review? Let me know if a rebase on 5.13-rc1 is needed. Thanks > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > --- > arch/riscv/include/asm/kprobes.h | 7 ------ > arch/riscv/kernel/probes/kprobes.c | 40 +++++++----------------------- > 2 files changed, 9 insertions(+), 38 deletions(-) > > diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h > index 4647d38018f6..9ea9b5ec3113 100644 > --- a/arch/riscv/include/asm/kprobes.h > +++ b/arch/riscv/include/asm/kprobes.h > @@ -29,18 +29,11 @@ struct prev_kprobe { > unsigned int status; > }; > > -/* Single step context for kprobe */ > -struct kprobe_step_ctx { > - unsigned long ss_pending; > - unsigned long match_addr; > -}; > - > /* per-cpu kprobe control block */ > struct kprobe_ctlblk { > unsigned int kprobe_status; > unsigned long saved_status; > struct prev_kprobe prev_kprobe; > - struct kprobe_step_ctx ss_ctx; > }; > > void arch_remove_kprobe(struct kprobe *p); > diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c > index 8c1f7a30aeed..4c1ad5536748 100644 > --- a/arch/riscv/kernel/probes/kprobes.c > +++ b/arch/riscv/kernel/probes/kprobes.c > @@ -17,7 +17,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; > DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); > > static void __kprobes > -post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); > +post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); > > static void __kprobes arch_prepare_ss_slot(struct kprobe *p) > { > @@ -43,7 +43,7 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) > p->ainsn.api.handler((u32)p->opcode, > (unsigned long)p->addr, regs); > > - post_kprobe_handler(kcb, regs); > + post_kprobe_handler(p, kcb, regs); > } > > int __kprobes arch_prepare_kprobe(struct kprobe *p) > @@ -149,21 +149,6 @@ static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, > regs->status = kcb->saved_status; > } > > -static void __kprobes > -set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p) > -{ > - unsigned long offset = GET_INSN_LENGTH(p->opcode); > - > - kcb->ss_ctx.ss_pending = true; > - kcb->ss_ctx.match_addr = addr + offset; > -} > - > -static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb) > -{ > - kcb->ss_ctx.ss_pending = false; > - kcb->ss_ctx.match_addr = 0; > -} > - > static void __kprobes setup_singlestep(struct kprobe *p, > struct pt_regs *regs, > struct kprobe_ctlblk *kcb, int reenter) > @@ -182,8 +167,6 @@ static void __kprobes setup_singlestep(struct kprobe *p, > /* prepare for single stepping */ > slot = (unsigned long)p->ainsn.api.insn; > > - set_ss_context(kcb, slot, p); /* mark pending ss */ > - > /* IRQs and single stepping do not mix well. */ > kprobes_save_local_irqflag(kcb, regs); > > @@ -219,13 +202,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p, > } > > static void __kprobes > -post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs) > +post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs) > { > - struct kprobe *cur = kprobe_running(); > - > - if (!cur) > - return; > - > /* return addr restore if non-branching insn */ > if (cur->ainsn.api.restore != 0) > regs->epc = cur->ainsn.api.restore; > @@ -355,16 +333,16 @@ bool __kprobes > kprobe_single_step_handler(struct pt_regs *regs) > { > struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); > + unsigned long addr = instruction_pointer(regs); > + struct kprobe *cur = kprobe_running(); > > - if ((kcb->ss_ctx.ss_pending) > - && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) { > - clear_ss_context(kcb); /* clear pending ss */ > - > + if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && > + ((unsigned long)&cur->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) == addr)) { > kprobes_restore_local_irqflag(kcb, regs); > - > - post_kprobe_handler(kcb, regs); > + post_kprobe_handler(cur, kcb, regs); > return true; > } > + /* not ours, kprobes should ignore it */ > return false; > } >
Hi Jisheng, On Wed, 12 May 2021 22:58:19 +0800 Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote: > On Mon, 19 Apr 2021 00:29:19 +0800 > Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote: > > > From: Jisheng Zhang <jszhang@kernel.org> > > > > Inspired by commit ba090f9cafd5 ("arm64: kprobes: Remove redundant > > kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx > > are redundant because those can be replaced by KPROBE_HIT_SS and > > &cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) > > respectively. > > > > Remove the kprobe_step_ctx to simplify the code. > > Hi all, > > This patch can still be applied to 5.13-rc1, could you please review? Let me > know if a rebase on 5.13-rc1 is needed. As far as I compared with arm64 code, this looks good to me. Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Thanks, > > Thanks > > > > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > --- > > arch/riscv/include/asm/kprobes.h | 7 ------ > > arch/riscv/kernel/probes/kprobes.c | 40 +++++++----------------------- > > 2 files changed, 9 insertions(+), 38 deletions(-) > > > > diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h > > index 4647d38018f6..9ea9b5ec3113 100644 > > --- a/arch/riscv/include/asm/kprobes.h > > +++ b/arch/riscv/include/asm/kprobes.h > > @@ -29,18 +29,11 @@ struct prev_kprobe { > > unsigned int status; > > }; > > > > -/* Single step context for kprobe */ > > -struct kprobe_step_ctx { > > - unsigned long ss_pending; > > - unsigned long match_addr; > > -}; > > - > > /* per-cpu kprobe control block */ > > struct kprobe_ctlblk { > > unsigned int kprobe_status; > > unsigned long saved_status; > > struct prev_kprobe prev_kprobe; > > - struct kprobe_step_ctx ss_ctx; > > }; > > > > void arch_remove_kprobe(struct kprobe *p); > > diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c > > index 8c1f7a30aeed..4c1ad5536748 100644 > > --- a/arch/riscv/kernel/probes/kprobes.c > > +++ b/arch/riscv/kernel/probes/kprobes.c > > @@ -17,7 +17,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; > > DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); > > > > static void __kprobes > > -post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); > > +post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); > > > > static void __kprobes arch_prepare_ss_slot(struct kprobe *p) > > { > > @@ -43,7 +43,7 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) > > p->ainsn.api.handler((u32)p->opcode, > > (unsigned long)p->addr, regs); > > > > - post_kprobe_handler(kcb, regs); > > + post_kprobe_handler(p, kcb, regs); > > } > > > > int __kprobes arch_prepare_kprobe(struct kprobe *p) > > @@ -149,21 +149,6 @@ static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, > > regs->status = kcb->saved_status; > > } > > > > -static void __kprobes > > -set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p) > > -{ > > - unsigned long offset = GET_INSN_LENGTH(p->opcode); > > - > > - kcb->ss_ctx.ss_pending = true; > > - kcb->ss_ctx.match_addr = addr + offset; > > -} > > - > > -static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb) > > -{ > > - kcb->ss_ctx.ss_pending = false; > > - kcb->ss_ctx.match_addr = 0; > > -} > > - > > static void __kprobes setup_singlestep(struct kprobe *p, > > struct pt_regs *regs, > > struct kprobe_ctlblk *kcb, int reenter) > > @@ -182,8 +167,6 @@ static void __kprobes setup_singlestep(struct kprobe *p, > > /* prepare for single stepping */ > > slot = (unsigned long)p->ainsn.api.insn; > > > > - set_ss_context(kcb, slot, p); /* mark pending ss */ > > - > > /* IRQs and single stepping do not mix well. */ > > kprobes_save_local_irqflag(kcb, regs); > > > > @@ -219,13 +202,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p, > > } > > > > static void __kprobes > > -post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs) > > +post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs) > > { > > - struct kprobe *cur = kprobe_running(); > > - > > - if (!cur) > > - return; > > - > > /* return addr restore if non-branching insn */ > > if (cur->ainsn.api.restore != 0) > > regs->epc = cur->ainsn.api.restore; > > @@ -355,16 +333,16 @@ bool __kprobes > > kprobe_single_step_handler(struct pt_regs *regs) > > { > > struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); > > + unsigned long addr = instruction_pointer(regs); > > + struct kprobe *cur = kprobe_running(); > > > > - if ((kcb->ss_ctx.ss_pending) > > - && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) { > > - clear_ss_context(kcb); /* clear pending ss */ > > - > > + if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && > > + ((unsigned long)&cur->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) == addr)) { > > kprobes_restore_local_irqflag(kcb, regs); > > - > > - post_kprobe_handler(kcb, regs); > > + post_kprobe_handler(cur, kcb, regs); > > return true; > > } > > + /* not ours, kprobes should ignore it */ > > return false; > > } > > > >
On Wed, 12 May 2021 07:58:19 PDT (-0700), jszhang3@mail.ustc.edu.cn wrote: > On Mon, 19 Apr 2021 00:29:19 +0800 > Jisheng Zhang <jszhang3@mail.ustc.edu.cn> wrote: > >> From: Jisheng Zhang <jszhang@kernel.org> >> >> Inspired by commit ba090f9cafd5 ("arm64: kprobes: Remove redundant >> kprobe_step_ctx"), the ss_pending and match_addr of kprobe_step_ctx >> are redundant because those can be replaced by KPROBE_HIT_SS and >> &cur_kprobe->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) >> respectively. >> >> Remove the kprobe_step_ctx to simplify the code. > > Hi all, > > This patch can still be applied to 5.13-rc1, could you please review? Let me > know if a rebase on 5.13-rc1 is needed. Sorry, I missed this one. This is on for-next. > > Thanks > >> >> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> >> --- >> arch/riscv/include/asm/kprobes.h | 7 ------ >> arch/riscv/kernel/probes/kprobes.c | 40 +++++++----------------------- >> 2 files changed, 9 insertions(+), 38 deletions(-) >> >> diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h >> index 4647d38018f6..9ea9b5ec3113 100644 >> --- a/arch/riscv/include/asm/kprobes.h >> +++ b/arch/riscv/include/asm/kprobes.h >> @@ -29,18 +29,11 @@ struct prev_kprobe { >> unsigned int status; >> }; >> >> -/* Single step context for kprobe */ >> -struct kprobe_step_ctx { >> - unsigned long ss_pending; >> - unsigned long match_addr; >> -}; >> - >> /* per-cpu kprobe control block */ >> struct kprobe_ctlblk { >> unsigned int kprobe_status; >> unsigned long saved_status; >> struct prev_kprobe prev_kprobe; >> - struct kprobe_step_ctx ss_ctx; >> }; >> >> void arch_remove_kprobe(struct kprobe *p); >> diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c >> index 8c1f7a30aeed..4c1ad5536748 100644 >> --- a/arch/riscv/kernel/probes/kprobes.c >> +++ b/arch/riscv/kernel/probes/kprobes.c >> @@ -17,7 +17,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; >> DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); >> >> static void __kprobes >> -post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); >> +post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); >> >> static void __kprobes arch_prepare_ss_slot(struct kprobe *p) >> { >> @@ -43,7 +43,7 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) >> p->ainsn.api.handler((u32)p->opcode, >> (unsigned long)p->addr, regs); >> >> - post_kprobe_handler(kcb, regs); >> + post_kprobe_handler(p, kcb, regs); >> } >> >> int __kprobes arch_prepare_kprobe(struct kprobe *p) >> @@ -149,21 +149,6 @@ static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, >> regs->status = kcb->saved_status; >> } >> >> -static void __kprobes >> -set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p) >> -{ >> - unsigned long offset = GET_INSN_LENGTH(p->opcode); >> - >> - kcb->ss_ctx.ss_pending = true; >> - kcb->ss_ctx.match_addr = addr + offset; >> -} >> - >> -static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb) >> -{ >> - kcb->ss_ctx.ss_pending = false; >> - kcb->ss_ctx.match_addr = 0; >> -} >> - >> static void __kprobes setup_singlestep(struct kprobe *p, >> struct pt_regs *regs, >> struct kprobe_ctlblk *kcb, int reenter) >> @@ -182,8 +167,6 @@ static void __kprobes setup_singlestep(struct kprobe *p, >> /* prepare for single stepping */ >> slot = (unsigned long)p->ainsn.api.insn; >> >> - set_ss_context(kcb, slot, p); /* mark pending ss */ >> - >> /* IRQs and single stepping do not mix well. */ >> kprobes_save_local_irqflag(kcb, regs); >> >> @@ -219,13 +202,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p, >> } >> >> static void __kprobes >> -post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs) >> +post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs) >> { >> - struct kprobe *cur = kprobe_running(); >> - >> - if (!cur) >> - return; >> - >> /* return addr restore if non-branching insn */ >> if (cur->ainsn.api.restore != 0) >> regs->epc = cur->ainsn.api.restore; >> @@ -355,16 +333,16 @@ bool __kprobes >> kprobe_single_step_handler(struct pt_regs *regs) >> { >> struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); >> + unsigned long addr = instruction_pointer(regs); >> + struct kprobe *cur = kprobe_running(); >> >> - if ((kcb->ss_ctx.ss_pending) >> - && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) { >> - clear_ss_context(kcb); /* clear pending ss */ >> - >> + if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && >> + ((unsigned long)&cur->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) == addr)) { >> kprobes_restore_local_irqflag(kcb, regs); >> - >> - post_kprobe_handler(kcb, regs); >> + post_kprobe_handler(cur, kcb, regs); >> return true; >> } >> + /* not ours, kprobes should ignore it */ >> return false; >> } >>
diff --git a/arch/riscv/include/asm/kprobes.h b/arch/riscv/include/asm/kprobes.h index 4647d38018f6..9ea9b5ec3113 100644 --- a/arch/riscv/include/asm/kprobes.h +++ b/arch/riscv/include/asm/kprobes.h @@ -29,18 +29,11 @@ struct prev_kprobe { unsigned int status; }; -/* Single step context for kprobe */ -struct kprobe_step_ctx { - unsigned long ss_pending; - unsigned long match_addr; -}; - /* per-cpu kprobe control block */ struct kprobe_ctlblk { unsigned int kprobe_status; unsigned long saved_status; struct prev_kprobe prev_kprobe; - struct kprobe_step_ctx ss_ctx; }; void arch_remove_kprobe(struct kprobe *p); diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 8c1f7a30aeed..4c1ad5536748 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -17,7 +17,7 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); static void __kprobes -post_kprobe_handler(struct kprobe_ctlblk *, struct pt_regs *); +post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { @@ -43,7 +43,7 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs) p->ainsn.api.handler((u32)p->opcode, (unsigned long)p->addr, regs); - post_kprobe_handler(kcb, regs); + post_kprobe_handler(p, kcb, regs); } int __kprobes arch_prepare_kprobe(struct kprobe *p) @@ -149,21 +149,6 @@ static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, regs->status = kcb->saved_status; } -static void __kprobes -set_ss_context(struct kprobe_ctlblk *kcb, unsigned long addr, struct kprobe *p) -{ - unsigned long offset = GET_INSN_LENGTH(p->opcode); - - kcb->ss_ctx.ss_pending = true; - kcb->ss_ctx.match_addr = addr + offset; -} - -static void __kprobes clear_ss_context(struct kprobe_ctlblk *kcb) -{ - kcb->ss_ctx.ss_pending = false; - kcb->ss_ctx.match_addr = 0; -} - static void __kprobes setup_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb, int reenter) @@ -182,8 +167,6 @@ static void __kprobes setup_singlestep(struct kprobe *p, /* prepare for single stepping */ slot = (unsigned long)p->ainsn.api.insn; - set_ss_context(kcb, slot, p); /* mark pending ss */ - /* IRQs and single stepping do not mix well. */ kprobes_save_local_irqflag(kcb, regs); @@ -219,13 +202,8 @@ static int __kprobes reenter_kprobe(struct kprobe *p, } static void __kprobes -post_kprobe_handler(struct kprobe_ctlblk *kcb, struct pt_regs *regs) +post_kprobe_handler(struct kprobe *cur, struct kprobe_ctlblk *kcb, struct pt_regs *regs) { - struct kprobe *cur = kprobe_running(); - - if (!cur) - return; - /* return addr restore if non-branching insn */ if (cur->ainsn.api.restore != 0) regs->epc = cur->ainsn.api.restore; @@ -355,16 +333,16 @@ bool __kprobes kprobe_single_step_handler(struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + unsigned long addr = instruction_pointer(regs); + struct kprobe *cur = kprobe_running(); - if ((kcb->ss_ctx.ss_pending) - && (kcb->ss_ctx.match_addr == instruction_pointer(regs))) { - clear_ss_context(kcb); /* clear pending ss */ - + if (cur && (kcb->kprobe_status & (KPROBE_HIT_SS | KPROBE_REENTER)) && + ((unsigned long)&cur->ainsn.api.insn[0] + GET_INSN_LENGTH(cur->opcode) == addr)) { kprobes_restore_local_irqflag(kcb, regs); - - post_kprobe_handler(kcb, regs); + post_kprobe_handler(cur, kcb, regs); return true; } + /* not ours, kprobes should ignore it */ return false; }