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Subject[RFC PATCH tip/master V3 5/8] kprobes/x86: Make boostable flag boolean
Date
Make arch_specific_insn.boostable to boolean, since it has
only 2 states, boostable or not. So it is better to use
boolean from the viewpoint of code readability.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
arch/x86/include/asm/kprobes.h | 7 +++----
arch/x86/kernel/kprobes/core.c | 12 ++++++------
arch/x86/kernel/kprobes/ftrace.c | 2 +-
3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/kprobes.h b/arch/x86/include/asm/kprobes.h
index 2005816..34b984c 100644
--- a/arch/x86/include/asm/kprobes.h
+++ b/arch/x86/include/asm/kprobes.h
@@ -72,14 +72,13 @@ struct arch_specific_insn {
/* copy of the original instruction */
kprobe_opcode_t *insn;
/*
- * boostable = -1: This instruction type is not boostable.
- * boostable = 0: This instruction type is boostable.
- * boostable = 1: This instruction has been boosted: we have
+ * boostable = false: This instruction type is not boostable.
+ * boostable = true: This instruction has been boosted: we have
* added a relative jump after the instruction copy in insn,
* so no single-step and fixup are needed (unless there's
* a post_handler or break_handler).
*/
- int boostable;
+ bool boostable;
bool if_modifier;
};

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index a654054..3f084a0 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -409,9 +409,9 @@ static void prepare_boost(struct kprobe *p, int length)
* jumps back to correct address.
*/
synthesize_reljump(p->ainsn.insn + length, p->addr + length);
- p->ainsn.boostable = 1;
+ p->ainsn.boostable = true;
} else {
- p->ainsn.boostable = -1;
+ p->ainsn.boostable = false;
}
}

@@ -467,7 +467,7 @@ void arch_disarm_kprobe(struct kprobe *p)
void arch_remove_kprobe(struct kprobe *p)
{
if (p->ainsn.insn) {
- free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
+ free_insn_slot(p->ainsn.insn, p->ainsn.boostable);
p->ainsn.insn = NULL;
}
}
@@ -539,7 +539,7 @@ static void setup_singlestep(struct kprobe *p, struct pt_regs *regs,
return;

#if !defined(CONFIG_PREEMPT)
- if (p->ainsn.boostable == 1 && !p->post_handler) {
+ if (p->ainsn.boostable && !p->post_handler) {
/* Boost up -- we can execute copied instructions directly */
if (!reenter)
reset_current_kprobe();
@@ -859,7 +859,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs,
case 0xcf:
case 0xea: /* jmp absolute -- ip is correct */
/* ip is already adjusted, no more changes required */
- p->ainsn.boostable = 1;
+ p->ainsn.boostable = true;
goto no_change;
case 0xe8: /* call relative - Fix return addr */
*tos = orig_ip + (*tos - copy_ip);
@@ -884,7 +884,7 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs,
* jmp near and far, absolute indirect
* ip is correct. And this is boostable
*/
- p->ainsn.boostable = 1;
+ p->ainsn.boostable = true;
goto no_change;
}
default:
diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c
index 5f8f0b3..041f7b6 100644
--- a/arch/x86/kernel/kprobes/ftrace.c
+++ b/arch/x86/kernel/kprobes/ftrace.c
@@ -94,6 +94,6 @@ NOKPROBE_SYMBOL(kprobe_ftrace_handler);
int arch_prepare_kprobe_ftrace(struct kprobe *p)
{
p->ainsn.insn = NULL;
- p->ainsn.boostable = -1;
+ p->ainsn.boostable = false;
return 0;
}
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