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Subject[PATCH v2 1/2] uprobes: Pass probed vaddr to arch_uprobe_analyze_insn()
From: Ananth N Mavinakayanahalli <>

On RISC architectures like powerpc, instructions are fixed size.
Instruction analysis on such platforms is just a matter of (insn % 4).
Pass the vaddr at which the uprobe is to be inserted so that
arch_uprobe_analyze_insn() can flag misaligned registration requests.

Changes in V2:
Pass (unsigned long)addr instead of (loff_t)vaddr to
arch_uprobe_analyze_insn(). We need the loff_t vaddr to take care of
the offset of inode:offset pair for large file sizes on 32bit.

Signed-off-by: Ananth N Mavinakaynahalli <>
arch/x86/include/asm/uprobes.h | 2 +-
arch/x86/kernel/uprobes.c | 3 ++-
kernel/events/uprobes.c | 2 +-
3 files changed, 4 insertions(+), 3 deletions(-)

Index: linux-3.5-rc1/arch/x86/include/asm/uprobes.h
--- linux-3.5-rc1.orig/arch/x86/include/asm/uprobes.h
+++ linux-3.5-rc1/arch/x86/include/asm/uprobes.h
@@ -48,7 +48,7 @@ struct arch_uprobe_task {

-extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm);
+extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr);
extern int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs);
extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs);
extern bool arch_uprobe_xol_was_trapped(struct task_struct *tsk);
Index: linux-3.5-rc1/arch/x86/kernel/uprobes.c
--- linux-3.5-rc1.orig/arch/x86/kernel/uprobes.c
+++ linux-3.5-rc1/arch/x86/kernel/uprobes.c
@@ -409,9 +409,10 @@ static int validate_insn_bits(struct arc
* arch_uprobe_analyze_insn - instruction analysis including validity and fixups.
* @mm: the probed address space.
* @arch_uprobe: the probepoint information.
+ * @addr: virtual address at which to install the probepoint
* Return 0 on success or a -ve number on error.
-int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm)
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long addr)
int ret;
struct insn insn;
Index: linux-3.5-rc1/kernel/events/uprobes.c
--- linux-3.5-rc1.orig/kernel/events/uprobes.c
+++ linux-3.5-rc1/kernel/events/uprobes.c
@@ -697,7 +697,7 @@ install_breakpoint(struct uprobe *uprobe
if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
return -EEXIST;

- ret = arch_uprobe_analyze_insn(&uprobe->arch, mm);
+ ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, addr);
if (ret)
return ret;

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