[PATCH RFC 2/3] kernel/events/uprobes: pass VMA to set_swbp(), set_orig_insn() and uprobe_write_opcode()

[David Hildenbrand]

We already have the VMA, no need to look it up using
get_user_page_vma_remote(). We can now switch to
get_user_pages_remote().

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
 arch/arm/probes/uprobes/core.c |  4 ++--
 include/linux/uprobes.h        |  6 +++---
 kernel/events/uprobes.c        | 33 +++++++++++++++++----------------
 3 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/arch/arm/probes/uprobes/core.c b/arch/arm/probes/uprobes/core.c
index f5f790c6e5f89..885e0c5e8c20d 100644
--- a/arch/arm/probes/uprobes/core.c
+++ b/arch/arm/probes/uprobes/core.c
@@ -26,10 +26,10 @@ bool is_swbp_insn(uprobe_opcode_t *insn)
 		(UPROBE_SWBP_ARM_INSN & 0x0fffffff);
 }
 
-int set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm,
+int set_swbp(struct arch_uprobe *auprobe, struct vm_area_struct *vma,
 	     unsigned long vaddr)
 {
-	return uprobe_write_opcode(auprobe, mm, vaddr,
+	return uprobe_write_opcode(auprobe, vma, vaddr,
 		   __opcode_to_mem_arm(auprobe->bpinsn));
 }
 
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index f46e0ca0169c7..77580dba6f8de 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -103,13 +103,13 @@ struct uprobes_state {
 };
 
 extern void __init uprobes_init(void);
-extern int set_swbp(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
-extern int set_orig_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long vaddr);
+extern int set_swbp(struct arch_uprobe *aup, struct vm_area_struct *vma, unsigned long vaddr);
+extern int set_orig_insn(struct arch_uprobe *aup, struct vm_area_struct *vma, unsigned long vaddr);
 extern bool is_swbp_insn(uprobe_opcode_t *insn);
 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);
+extern int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma, unsigned long vaddr, uprobe_opcode_t);
 extern int uprobe_register(struct inode *inode, loff_t offset, struct uprobe_consumer *uc);
 extern int uprobe_register_refctr(struct inode *inode, loff_t offset, loff_t ref_ctr_offset, struct uprobe_consumer *uc);
 extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_consumer *uc, bool);
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c6d6b7a8e4410..f2b1fef7f1d62 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -449,19 +449,19 @@ static int update_ref_ctr(struct uprobe *uprobe, struct mm_struct *mm,
  *
  * uprobe_write_opcode - write the opcode at a given virtual address.
  * @auprobe: arch specific probepoint information.
- * @mm: the probed process address space.
+ * @vma: the probed virtual memory area.
  * @vaddr: the virtual address to store the opcode.
  * @opcode: opcode to be written at @vaddr.
  *
  * Called with mm->mmap_lock held for write.
  * 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 opcode)
+int uprobe_write_opcode(struct arch_uprobe *auprobe, struct vm_area_struct *vma,
+		unsigned long vaddr, uprobe_opcode_t opcode)
 {
+	struct mm_struct *mm = vma->vm_mm;
 	struct uprobe *uprobe;
 	struct page *old_page, *new_page;
-	struct vm_area_struct *vma;
 	int ret, is_register, ref_ctr_updated = 0;
 	bool orig_page_huge = false;
 	unsigned int gup_flags = FOLL_FORCE;
@@ -473,9 +473,9 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
 	if (is_register)
 		gup_flags |= FOLL_SPLIT_PMD;
 	/* Read the page with vaddr into memory */
-	old_page = get_user_page_vma_remote(mm, vaddr, gup_flags, &vma);
-	if (IS_ERR(old_page))
-		return PTR_ERR(old_page);
+	ret = get_user_pages_remote(mm, vaddr, 1, gup_flags, &old_page, NULL);
+	if (ret != 1)
+		return ret;
 
 	ret = verify_opcode(old_page, vaddr, &opcode);
 	if (ret <= 0)
@@ -560,30 +560,31 @@ int uprobe_write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm,
 /**
  * set_swbp - store breakpoint at a given address.
  * @auprobe: arch specific probepoint information.
- * @mm: the probed process address space.
+ * @vma: the probed virtual memory area.
  * @vaddr: the virtual address to insert the opcode.
  *
  * For mm @mm, store the breakpoint instruction at @vaddr.
  * Return 0 (success) or a negative errno.
  */
-int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
+int __weak set_swbp(struct arch_uprobe *auprobe, struct vm_area_struct *vma,
+		unsigned long vaddr)
 {
-	return uprobe_write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN);
+	return uprobe_write_opcode(auprobe, vma, vaddr, UPROBE_SWBP_INSN);
 }
 
 /**
  * set_orig_insn - Restore the original instruction.
- * @mm: the probed process address space.
+ * @vma: the probed virtual memory area.
  * @auprobe: arch specific probepoint information.
  * @vaddr: the virtual address to insert the opcode.
  *
  * For mm @mm, restore the original opcode (opcode) at @vaddr.
  * Return 0 (success) or a negative errno.
  */
-int __weak
-set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr)
+int __weak set_orig_insn(struct arch_uprobe *auprobe,
+		struct vm_area_struct *vma, unsigned long vaddr)
 {
-	return uprobe_write_opcode(auprobe, mm, vaddr,
+	return uprobe_write_opcode(auprobe, vma, vaddr,
 			*(uprobe_opcode_t *)&auprobe->insn);
 }
 
@@ -905,7 +906,7 @@ static int install_breakpoint(struct uprobe *uprobe, struct vm_area_struct *vma,
 	if (first_uprobe)
 		set_bit(MMF_HAS_UPROBES, &mm->flags);
 
-	ret = set_swbp(&uprobe->arch, mm, vaddr);
+	ret = set_swbp(&uprobe->arch, vma, vaddr);
 	if (!ret)
 		clear_bit(MMF_RECALC_UPROBES, &mm->flags);
 	else if (first_uprobe)
@@ -920,7 +921,7 @@ static int remove_breakpoint(struct uprobe *uprobe, struct vm_area_struct *vma,
 	struct mm_struct *mm = vma->vm_mm;
 
 	set_bit(MMF_RECALC_UPROBES, &mm->flags);
-	return set_orig_insn(&uprobe->arch, mm, vaddr);
+	return set_orig_insn(&uprobe->arch, vma, vaddr);
 }
 
 static inline bool uprobe_is_active(struct uprobe *uprobe)
-- 
2.45.1