Re: [PATCHv6 perf/core 10/22] uprobes/x86: Add support to optimize uprobes
From: Jiri Olsa <hidden>
Date: 2025-09-03 06:48:51
Also in:
bpf, lkml
Subsystem:
the rest, uprobes, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Masami Hiramatsu, Oleg Nesterov, Peter Zijlstra, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
On Tue, Aug 19, 2025 at 09:15:15PM +0200, Peter Zijlstra wrote:
On Sun, Jul 20, 2025 at 01:21:20PM +0200, Jiri Olsa wrote:quoted
+static bool __is_optimized(uprobe_opcode_t *insn, unsigned long vaddr) +{ + struct __packed __arch_relative_insn { + u8 op; + s32 raddr; + } *call = (struct __arch_relative_insn *) insn;Not something you need to clean up now I suppose, but we could do with unifying this thing. we have a bunch of instances around.
found two below, maybe we could use 'union text_poke_insn' instead like below? jirka ---
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 6079d15dab8c..7fd03897d776 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c@@ -109,14 +109,10 @@ const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist); static nokprobe_inline void __synthesize_relative_insn(void *dest, void *from, void *to, u8 op) { - struct __arch_relative_insn { - u8 op; - s32 raddr; - } __packed *insn; - - insn = (struct __arch_relative_insn *)dest; - insn->raddr = (s32)((long)(to) - ((long)(from) + 5)); - insn->op = op; + union text_poke_insn *insn = dest; + + insn->disp = (s32)((long)(to) - ((long)(from) + 5)); + insn->opcode = op; } /* Insert a jump instruction at address 'from', which jumps to address 'to'.*/
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 0a8c0a4a5423..bac14f3165c3 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c@@ -1046,14 +1046,11 @@ static int copy_from_vaddr(struct mm_struct *mm, unsigned long vaddr, void *dst, static bool __is_optimized(uprobe_opcode_t *insn, unsigned long vaddr) { - struct __packed __arch_relative_insn { - u8 op; - s32 raddr; - } *call = (struct __arch_relative_insn *) insn; + union text_poke_insn *call = (union text_poke_insn *) insn; if (!is_call_insn(insn)) return false; - return __in_uprobe_trampoline(vaddr + 5 + call->raddr); + return __in_uprobe_trampoline(vaddr + 5 + call->disp); } static int is_optimized(struct mm_struct *mm, unsigned long vaddr)