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.
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
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 518b26756469..5080619560d4 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 1e5dc3b30707..6795b8d82b9c 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -492,12 +492,12 @@ 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;
@@ -538,7 +538,7 @@ 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);
@@ -590,7 +590,7 @@ 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 */
--
2.50.0
