From 18a111256a0b4fedfe47101f084441a84d7e357a Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Sun, 20 Jul 2025 13:21:17 +0200 Subject: [PATCH] uprobes: Add do_ref_ctr argument to uprobe_write function Making update_ref_ctr call in uprobe_write conditional based on do_ref_ctr argument. This way we can use uprobe_write for instruction update without doing ref_ctr_offset update. Signed-off-by: Jiri Olsa Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Masami Hiramatsu (Google) Acked-by: Andrii Nakryiko Acked-by: Oleg Nesterov Link: https://lore.kernel.org/r/20250720112133.244369-8-jolsa@kernel.org --- include/linux/uprobes.h | 2 +- kernel/events/uprobes.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 518b267564698..5080619560d42 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -200,7 +200,7 @@ extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs); extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma, unsigned long vaddr, uprobe_opcode_t, bool is_register); extern int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, const unsigned long opcode_vaddr, - uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify, bool is_register); + uprobe_opcode_t *insn, int nbytes, uprobe_write_verify_t verify, bool is_register, bool do_update_ref_ctr); extern struct uprobe *uprobe_register(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc); extern int uprobe_apply(struct uprobe *uprobe, struct uprobe_consumer *uc, bool); extern void uprobe_unregister_nosync(struct uprobe *uprobe, struct uprobe_consumer *uc); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 955e5ed3e383c..da2b3d0deab62 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -491,12 +491,12 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma, bool is_register) { return uprobe_write(auprobe, vma, opcode_vaddr, &opcode, UPROBE_SWBP_INSN_SIZE, - verify_opcode, is_register); + verify_opcode, is_register, true /* do_update_ref_ctr */); } int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, const unsigned long insn_vaddr, uprobe_opcode_t *insn, int nbytes, - uprobe_write_verify_t verify, bool is_register) + uprobe_write_verify_t verify, bool is_register, bool do_update_ref_ctr) { const unsigned long vaddr = insn_vaddr & PAGE_MASK; struct mm_struct *mm = vma->vm_mm; @@ -537,7 +537,7 @@ retry: } /* We are going to replace instruction, update ref_ctr. */ - if (!ref_ctr_updated && uprobe->ref_ctr_offset) { + if (do_update_ref_ctr && !ref_ctr_updated && uprobe->ref_ctr_offset) { ret = update_ref_ctr(uprobe, mm, is_register ? 1 : -1); if (ret) { folio_put(folio); @@ -589,7 +589,7 @@ retry: out: /* Revert back reference counter if instruction update failed. */ - if (ret < 0 && ref_ctr_updated) + if (do_update_ref_ctr && ret < 0 && ref_ctr_updated) update_ref_ctr(uprobe, mm, is_register ? -1 : 1); /* try collapse pmd for compound page */ -- 2.47.3