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LoongArch: Use larch_insn_gen_break() for kprobes 

For now, we can use larch_insn_gen_break() to define KPROBE_BP_INSN and
KPROBE_SSTEPBP_INSN. Because larch_insn_gen_break() returns instruction
word, define kprobe_opcode_t as u32, then do some small changes related
with type conversion, no functional change intended.

Tested-by: Jeff Xie <xiehuan09@gmail.com>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Tiezhu Yang 2023-06-29 20:58:44 +08:00 committed by Huacai Chen
parent 49ed320da5
commit 6e32036333
2 changed files with 15 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/loongarch/include/asm/kprobes.h
View File

@ -22,7 +22,7 @@ do { \
#define kretprobe_blacklist_size 0
typedef union loongarch_instruction kprobe_opcode_t;
typedef u32 kprobe_opcode_t;
/* Architecture specific copy of original instruction */
struct arch_specific_insn {

33
arch/loongarch/kernel/kprobes.c
View File

@ -4,19 +4,8 @@
#include <linux/preempt.h>
#include <asm/break.h>
static const union loongarch_instruction breakpoint_insn = {
.reg0i15_format = {
.opcode = break_op,
.immediate = BRK_KPROBE_BP,
}
};
static const union loongarch_instruction singlestep_insn = {
.reg0i15_format = {
.opcode = break_op,
.immediate = BRK_KPROBE_SSTEPBP,
}
};
#define KPROBE_BP_INSN larch_insn_gen_break(BRK_KPROBE_BP)
#define KPROBE_SSTEPBP_INSN larch_insn_gen_break(BRK_KPROBE_SSTEPBP)
DEFINE_PER_CPU(struct kprobe *, current_kprobe);
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@ -24,7 +13,7 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
static void arch_prepare_ss_slot(struct kprobe *p)
{
p->ainsn.insn[0] = *p->addr;
p->ainsn.insn[1] = singlestep_insn;
p->ainsn.insn[1] = KPROBE_SSTEPBP_INSN;
p->ainsn.restore = (unsigned long)p->addr + LOONGARCH_INSN_SIZE;
}
NOKPROBE_SYMBOL(arch_prepare_ss_slot);
@ -37,17 +26,20 @@ NOKPROBE_SYMBOL(arch_prepare_simulate);
int arch_prepare_kprobe(struct kprobe *p)
{
union loongarch_instruction insn;
if ((unsigned long)p->addr & 0x3)
return -EILSEQ;
/* copy instruction */
p->opcode = *p->addr;
insn.word = p->opcode;
/* decode instruction */
if (insns_not_supported(p->opcode))
if (insns_not_supported(insn))
return -EINVAL;
if (insns_need_simulation(p->opcode)) {
if (insns_need_simulation(insn)) {
p->ainsn.insn = NULL;
} else {
p->ainsn.insn = get_insn_slot();
@ -68,7 +60,7 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe);
/* Install breakpoint in text */
void arch_arm_kprobe(struct kprobe *p)
{
*p->addr = breakpoint_insn;
*p->addr = KPROBE_BP_INSN;
flush_insn_slot(p);
}
NOKPROBE_SYMBOL(arch_arm_kprobe);
@ -163,6 +155,8 @@ NOKPROBE_SYMBOL(post_kprobe_handler);
static void setup_singlestep(struct kprobe *p, struct pt_regs *regs,
struct kprobe_ctlblk *kcb, int reenter)
{
union loongarch_instruction insn;
if (reenter) {
save_previous_kprobe(kcb);
set_current_kprobe(p);
@ -178,7 +172,8 @@ static void setup_singlestep(struct kprobe *p, struct pt_regs *regs,
regs->csr_era = (unsigned long)p->ainsn.insn;
} else {
/* simulate single steping */
arch_simulate_insn(p->opcode, regs);
insn.word = p->opcode;
arch_simulate_insn(insn, regs);
/* now go for post processing */
post_kprobe_handler(p, kcb, regs);
}
@ -253,7 +248,7 @@ bool kprobe_breakpoint_handler(struct pt_regs *regs)
}
}
if (addr->word != breakpoint_insn.word) {
if (*addr != KPROBE_BP_INSN) {
/*
* The breakpoint instruction was removed right
* after we hit it. Another cpu has removed