[RFC perf/core 02/11] uprobes: Make copy_from_page global

From: Jiri Olsa
Date: Tue Nov 05 2024 - 08:34:52 EST


Making copy_from_page global and adding uprobe prefix.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
include/linux/uprobes.h | 1 +
kernel/events/uprobes.c | 10 +++++-----
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 2f500bc97263..28068f9fcdc1 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -213,6 +213,7 @@ extern void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
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);
#else /* !CONFIG_UPROBES */
struct uprobes_state {
};
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 0b04c051d712..e9308649bba3 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -250,7 +250,7 @@ bool __weak is_trap_insn(uprobe_opcode_t *insn)
return is_swbp_insn(insn);
}

-static void copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len)
+void uprobe_copy_from_page(struct page *page, unsigned long vaddr, void *dst, int len)
{
void *kaddr = kmap_atomic(page);
memcpy(dst, kaddr + (vaddr & ~PAGE_MASK), len);
@@ -278,7 +278,7 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
* is a trap variant; uprobes always wins over any other (gdb)
* breakpoint.
*/
- copy_from_page(page, vaddr, &old_opcode, UPROBE_SWBP_INSN_SIZE);
+ uprobe_copy_from_page(page, vaddr, &old_opcode, UPROBE_SWBP_INSN_SIZE);
is_swbp = is_swbp_insn(&old_opcode);

if (is_swbp_insn(new_opcode)) {
@@ -1027,7 +1027,7 @@ static int __copy_insn(struct address_space *mapping, struct file *filp,
if (IS_ERR(page))
return PTR_ERR(page);

- copy_from_page(page, offset, insn, nbytes);
+ uprobe_copy_from_page(page, offset, insn, nbytes);
put_page(page);

return 0;
@@ -1368,7 +1368,7 @@ struct uprobe *uprobe_register(struct inode *inode,
return ERR_PTR(-EINVAL);

/*
- * This ensures that copy_from_page(), copy_to_page() and
+ * This ensures that uprobe_copy_from_page(), copy_to_page() and
* __update_ref_ctr() can't cross page boundary.
*/
if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
@@ -2288,7 +2288,7 @@ static int is_trap_at_addr(struct mm_struct *mm, unsigned long vaddr)
if (result < 0)
return result;

- copy_from_page(page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+ uprobe_copy_from_page(page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
put_page(page);
out:
/* This needs to return true for any variant of the trap insn */
--
2.47.0