Commit 18a11125 authored by Jiri Olsa's avatar Jiri Olsa Committed by Peter Zijlstra
Browse files

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: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250720112133.244369-8-jolsa@kernel.org
parent ec46350f

include/linux/uprobes.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

kernel/events/uprobes.c

+4 −4
Original line number Diff line number Diff line
@@ -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 @@ int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, 
	}



	/* 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 @@ int uprobe_write(struct arch_uprobe *auprobe, struct vm_area_struct *vma, 


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 */