[bpf-next,02/13] uprobes: Make copy_from_page global

Commit Message

Jiri Olsa Dec. 11, 2024, 1:33 p.m. UTC

Making copy_from_page global and adding uprobe prefix.
Adding the uprobe prefix to copy_to_page as well for symmetry.

Signed-off-by: Jiri Olsa <[e-mail]>
---
 include/linux/uprobes.h |  1 +
 kernel/events/uprobes.c | 16 ++++++++--------
 2 files changed, 9 insertions(+), 8 deletions(-)

Comments

Andrii Nakryiko Dec. 13, 2024, 12:43 a.m. UTC | #1

On Wed, Dec 11, 2024 at 5:34 AM Jiri Olsa <[e-mail]> wrote:
>
> Making copy_from_page global and adding uprobe prefix.
> Adding the uprobe prefix to copy_to_page as well for symmetry.
>
> Signed-off-by: Jiri Olsa <[e-mail]>
> ---
>  include/linux/uprobes.h |  1 +
>  kernel/events/uprobes.c | 16 ++++++++--------
>  2 files changed, 9 insertions(+), 8 deletions(-)
>

Acked-by: Andrii Nakryiko <[e-mail]>

> diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
> index 09a298e416a8..e24fbe496efb 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 e0e3ebb4c0a1..61ec91f635dc 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -249,14 +249,14 @@ 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);
>         kunmap_atomic(kaddr);
>  }
>
> -static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
> +static void uprobe_copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
>  {
>         void *kaddr = kmap_atomic(page);
>         memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
> @@ -277,7 +277,7 @@ 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)) {
> @@ -524,7 +524,7 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
>
>         __SetPageUptodate(new_page);
>         copy_highpage(new_page, old_page);
> -       copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
> +       uprobe_copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
>
>         if (!is_register) {
>                 struct page *orig_page;
> @@ -1026,7 +1026,7 @@ 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;
> @@ -1367,7 +1367,7 @@ 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(), uprobe_copy_to_page() and
>          * __update_ref_ctr() can't cross page boundary.
>          */
>         if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
> @@ -1856,7 +1856,7 @@ void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
>                                   void *src, unsigned long len)
>  {
>         /* Initialize the slot */
> -       copy_to_page(page, vaddr, src, len);
> +       uprobe_copy_to_page(page, vaddr, src, len);
>
>         /*
>          * We probably need flush_icache_user_page() but it needs vma.
> @@ -2287,7 +2287,7 @@ 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
>

Patch

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 09a298e416a8..e24fbe496efb 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 e0e3ebb4c0a1..61ec91f635dc 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -249,14 +249,14 @@  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);
 	kunmap_atomic(kaddr);
 }
 
-static void copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
+static void uprobe_copy_to_page(struct page *page, unsigned long vaddr, const void *src, int len)
 {
 	void *kaddr = kmap_atomic(page);
 	memcpy(kaddr + (vaddr & ~PAGE_MASK), src, len);
@@ -277,7 +277,7 @@  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)) {
@@ -524,7 +524,7 @@  int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
 
 	__SetPageUptodate(new_page);
 	copy_highpage(new_page, old_page);
-	copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
+	uprobe_copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE);
 
 	if (!is_register) {
 		struct page *orig_page;
@@ -1026,7 +1026,7 @@  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;
@@ -1367,7 +1367,7 @@  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(), uprobe_copy_to_page() and
 	 * __update_ref_ctr() can't cross page boundary.
 	 */
 	if (!IS_ALIGNED(offset, UPROBE_SWBP_INSN_SIZE))
@@ -1856,7 +1856,7 @@  void __weak arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr,
 				  void *src, unsigned long len)
 {
 	/* Initialize the slot */
-	copy_to_page(page, vaddr, src, len);
+	uprobe_copy_to_page(page, vaddr, src, len);
 
 	/*
 	 * We probably need flush_icache_user_page() but it needs vma.
@@ -2287,7 +2287,7 @@  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 */