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authorPu Lehui <pulehui@huawei.com>2023-02-15 16:52:02 +0300
committerDaniel Borkmann <daniel@iogearbox.net>2023-02-17 23:45:30 +0300
commit5e57fb7b0bd3ea7e994ef1c0ab3562d1fe0676b2 (patch)
tree150dfe4d1f95aec03c11f35144a27cb39bf117e5 /arch/riscv
parent181127fb76e62d06ab17a75fd610129688612343 (diff)
downloadlinux-5e57fb7b0bd3ea7e994ef1c0ab3562d1fe0676b2.tar.xz
riscv: Extend patch_text for multiple instructions
Extend patch_text for multiple instructions. This is the preparaiton for multiple instructions text patching in riscv BPF trampoline, and may be useful for other scenario. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Acked-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/bpf/20230215135205.1411105-2-pulehui@huaweicloud.com
Diffstat (limited to 'arch/riscv')
-rw-r--r--arch/riscv/include/asm/patch.h2
-rw-r--r--arch/riscv/kernel/patch.c19
-rw-r--r--arch/riscv/kernel/probes/kprobes.c15
3 files changed, 21 insertions, 15 deletions
diff --git a/arch/riscv/include/asm/patch.h b/arch/riscv/include/asm/patch.h
index 9a7d7346001e..f433121774c0 100644
--- a/arch/riscv/include/asm/patch.h
+++ b/arch/riscv/include/asm/patch.h
@@ -7,6 +7,6 @@
#define _ASM_RISCV_PATCH_H
int patch_text_nosync(void *addr, const void *insns, size_t len);
-int patch_text(void *addr, u32 insn);
+int patch_text(void *addr, u32 *insns, int ninsns);
#endif /* _ASM_RISCV_PATCH_H */
diff --git a/arch/riscv/kernel/patch.c b/arch/riscv/kernel/patch.c
index 765004b60513..8086d1a281cd 100644
--- a/arch/riscv/kernel/patch.c
+++ b/arch/riscv/kernel/patch.c
@@ -15,7 +15,8 @@
struct patch_insn {
void *addr;
- u32 insn;
+ u32 *insns;
+ int ninsns;
atomic_t cpu_count;
};
@@ -102,12 +103,15 @@ NOKPROBE_SYMBOL(patch_text_nosync);
static int patch_text_cb(void *data)
{
struct patch_insn *patch = data;
- int ret = 0;
+ unsigned long len;
+ int i, ret = 0;
if (atomic_inc_return(&patch->cpu_count) == num_online_cpus()) {
- ret =
- patch_text_nosync(patch->addr, &patch->insn,
- GET_INSN_LENGTH(patch->insn));
+ for (i = 0; ret == 0 && i < patch->ninsns; i++) {
+ len = GET_INSN_LENGTH(patch->insns[i]);
+ ret = patch_text_nosync(patch->addr + i * len,
+ &patch->insns[i], len);
+ }
atomic_inc(&patch->cpu_count);
} else {
while (atomic_read(&patch->cpu_count) <= num_online_cpus())
@@ -119,11 +123,12 @@ static int patch_text_cb(void *data)
}
NOKPROBE_SYMBOL(patch_text_cb);
-int patch_text(void *addr, u32 insn)
+int patch_text(void *addr, u32 *insns, int ninsns)
{
struct patch_insn patch = {
.addr = addr,
- .insn = insn,
+ .insns = insns,
+ .ninsns = ninsns,
.cpu_count = ATOMIC_INIT(0),
};
diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c
index 41c7481afde3..ef6d6e702485 100644
--- a/arch/riscv/kernel/probes/kprobes.c
+++ b/arch/riscv/kernel/probes/kprobes.c
@@ -23,13 +23,14 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
{
+ u32 insn = __BUG_INSN_32;
unsigned long offset = GET_INSN_LENGTH(p->opcode);
p->ainsn.api.restore = (unsigned long)p->addr + offset;
- patch_text(p->ainsn.api.insn, p->opcode);
+ patch_text(p->ainsn.api.insn, &p->opcode, 1);
patch_text((void *)((unsigned long)(p->ainsn.api.insn) + offset),
- __BUG_INSN_32);
+ &insn, 1);
}
static void __kprobes arch_prepare_simulate(struct kprobe *p)
@@ -114,16 +115,16 @@ void *alloc_insn_page(void)
/* install breakpoint in text */
void __kprobes arch_arm_kprobe(struct kprobe *p)
{
- if ((p->opcode & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
- patch_text(p->addr, __BUG_INSN_32);
- else
- patch_text(p->addr, __BUG_INSN_16);
+ u32 insn = (p->opcode & __INSN_LENGTH_MASK) == __INSN_LENGTH_32 ?
+ __BUG_INSN_32 : __BUG_INSN_16;
+
+ patch_text(p->addr, &insn, 1);
}
/* remove breakpoint from text */
void __kprobes arch_disarm_kprobe(struct kprobe *p)
{
- patch_text(p->addr, p->opcode);
+ patch_text(p->addr, &p->opcode, 1);
}
void __kprobes arch_remove_kprobe(struct kprobe *p)