[PATCH bpf-next 04/13] uprobes: Add arch_uprobe_verify_opcode function

Jiri Olsa
2024-12-11T13:34:52Z

Adding arch_uprobe_verify_opcode function, so we can overload
verification for each architecture in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
include/linux/uprobes.h | 5 +++++
kernel/events/uprobes.c | 19 ++++++++++++++++---
2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index cc723bc48c1d..8843b7f99ed0 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -215,6 +215,11 @@ extern void uprobe_handle_trampoline(struct pt_regs *regs);
extern void *arch_uretprobe_trampoline(unsigned long *psize);
extern unsigned long uprobe_get_trampoline_vaddr(void);
extern void uprobe_copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len);
+extern int uprobe_verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode);
+extern int arch_uprobe_verify_opcode(struct arch_uprobe *auprobe, struct page *page,
+ unsigned long vaddr, uprobe_opcode_t *new_opcode,
+ int nbytes);
+extern bool arch_uprobe_is_register(uprobe_opcode_t *insn, int nbytes);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 7c2ecf11a573..8068f91de9e3 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -263,7 +263,13 @@ static void uprobe_copy_to_page(struct page *page, unsigned long vaddr, const vo
kunmap_atomic(kaddr);
}

-static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t *new_opcode)
+__weak bool arch_uprobe_is_register(uprobe_opcode_t *insn, int nbytes)
+{
+ return is_swbp_insn(insn);
+}
+
+int uprobe_verify_opcode(struct page *page, unsigned long vaddr,
+ uprobe_opcode_t *new_opcode)
{
uprobe_opcode_t old_opcode;
bool is_swbp;
@@ -291,6 +297,13 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
return 1;
}

+__weak int arch_uprobe_verify_opcode(struct arch_uprobe *auprobe, struct page *page,
+ unsigned long vaddr, uprobe_opcode_t *new_opcode,
+ int nbytes)
+{
+ return uprobe_verify_opcode(page, vaddr, new_opcode);
+}
+
static struct delayed_uprobe *
delayed_uprobe_check(struct uprobe *uprobe, struct mm_struct *mm)
{
@@ -479,7 +492,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
bool orig_page_huge = false;
unsigned int gup_flags = FOLL_FORCE;

- is_register = is_swbp_insn(insn);
+ is_register = arch_uprobe_is_register(insn, nbytes);
uprobe = container_of(auprobe, struct uprobe, arch);

retry:
@@ -490,7 +503,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
if (IS_ERR(old_page))
return PTR_ERR(old_page);

- ret = verify_opcode(old_page, vaddr, insn);
+ ret = arch_uprobe_verify_opcode(auprobe, old_page, vaddr, insn, nbytes);
if (ret <= 0)
goto put_old;

--
2.47.0