From 8c9f4940c27dd72ee68ca5af2922e4d83ca9121b Mon Sep 17 00:00:00 2001 From: Jisheng Zhang Date: Mon, 19 Apr 2021 00:29:19 +0800 Subject: riscv: kprobes: Remove redundant kprobe_step_ctx 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. Signed-off-by: Jisheng Zhang Reviewed-by: Masami Hiramatsu Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/probes/kprobes.c | 40 +++++++++----------------------------- 1 file changed, 9 insertions(+), 31 deletions(-) (limited to 'arch/riscv/kernel/probes') diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index 10b965c34536..fbd127d5dc04 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; @@ -357,16 +335,16 @@ 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; } -- cgit v1.2.3