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-rw-r--r--kernel/events/uprobes.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 94d38a39d72e..c74761004ee5 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -474,14 +474,17 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
struct vm_area_struct *vma;
int ret, is_register, ref_ctr_updated = 0;
bool orig_page_huge = false;
+ unsigned int gup_flags = FOLL_FORCE;
is_register = is_swbp_insn(&opcode);
uprobe = container_of(auprobe, struct uprobe, arch);
retry:
+ if (is_register)
+ gup_flags |= FOLL_SPLIT_PMD;
/* Read the page with vaddr into memory */
- ret = get_user_pages_remote(NULL, mm, vaddr, 1,
- FOLL_FORCE | FOLL_SPLIT_PMD, &old_page, &vma, NULL);
+ ret = get_user_pages_remote(NULL, mm, vaddr, 1, gup_flags,
+ &old_page, &vma, NULL);
if (ret <= 0)
return ret;
@@ -489,6 +492,12 @@ retry:
if (ret <= 0)
goto put_old;
+ if (WARN(!is_register && PageCompound(old_page),
+ "uprobe unregister should never work on compound page\n")) {
+ ret = -EINVAL;
+ goto put_old;
+ }
+
/* We are going to replace instruction, update ref_ctr. */
if (!ref_ctr_updated && uprobe->ref_ctr_offset) {
ret = update_ref_ctr(uprobe, mm, is_register ? 1 : -1);