[RFC perf/core 04/11] uprobes: Add data argument to uprobe_write_opcode function

[Jiri Olsa <jolsa@kernel.org>]

Adding data argument to uprobe_write_opcode function and passing
it to newly added arch overloaded functions:

  arch_uprobe_verify_opcode
  arch_uprobe_is_register

This way each architecture can provide custmized verification.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 include/linux/uprobes.h |  6 +++++-
 kernel/events/uprobes.c | 25 +++++++++++++++++++------
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 7d23a4fee6f4..be306028ed59 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -182,7 +182,7 @@ extern bool is_trap_insn(uprobe_opcode_t *insn);
 extern unsigned long uprobe_get_swbp_addr(struct pt_regs *regs);
 extern unsigned long uprobe_get_trap_addr(struct pt_regs *regs);
 extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
-			       unsigned long vaddr, uprobe_opcode_t *insn, int len);
+			       unsigned long vaddr, uprobe_opcode_t *insn, int len, void *data);
 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);
@@ -215,6 +215,10 @@ 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 page *page, unsigned long vaddr,
+				     uprobe_opcode_t *new_opcode, void *data);
+extern bool arch_uprobe_is_register(uprobe_opcode_t *insn, int len, void *data);
 #else /* !CONFIG_UPROBES */
 struct uprobes_state {
 };
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 3e275717789b..944d9df1f081 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -264,7 +264,13 @@ static void copy_to_page(struct page *page, unsigned long vaddr, const void *src
 	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 len, void *data)
+{
+	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;
@@ -292,6 +298,12 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t
 	return 1;
 }
 
+__weak int arch_uprobe_verify_opcode(struct page *page, unsigned long vaddr,
+				     uprobe_opcode_t *new_opcode, void *data)
+{
+	return uprobe_verify_opcode(page, vaddr, new_opcode);
+}
+
 static struct delayed_uprobe *
 delayed_uprobe_check(struct uprobe *uprobe, struct mm_struct *mm)
 {
@@ -471,7 +483,8 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm,
  * Return 0 (success) or a negative errno.
  */
 int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
-			unsigned long vaddr, uprobe_opcode_t *insn, int len)
+			unsigned long vaddr, uprobe_opcode_t *insn, int len,
+			void *data)
 {
 	struct uprobe *uprobe;
 	struct page *old_page, *new_page;
@@ -480,7 +493,7 @@ 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, len, data);
 	uprobe = container_of(auprobe, struct uprobe, arch);
 
 retry:
@@ -491,7 +504,7 @@ 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(old_page, vaddr, insn, data);
 	if (ret <= 0)
 		goto put_old;
 
@@ -584,7 +597,7 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned
 {
 	uprobe_opcode_t insn = UPROBE_SWBP_INSN;
 
-	return uprobe_write_opcode(auprobe, mm, vaddr, &insn, UPROBE_SWBP_INSN_SIZE);
+	return uprobe_write_opcode(auprobe, mm, vaddr, &insn, UPROBE_SWBP_INSN_SIZE, NULL);
 }
 
 /**
@@ -600,7 +613,7 @@ int __weak
 set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
 {
 	return uprobe_write_opcode(auprobe, mm, vaddr,
-			(uprobe_opcode_t *)&auprobe->insn, UPROBE_SWBP_INSN_SIZE);
+			(uprobe_opcode_t *)&auprobe->insn, UPROBE_SWBP_INSN_SIZE, NULL);
 }
 
 /* uprobe should have guaranteed positive refcount */
-- 
2.47.0