[PATCH 5/9] uprobes: add arch write opcode hook
From: David Long <hidden>
Date: 2013-08-01 23:47:13
Also in:
lkml
Subsystem:
performance events subsystem, the rest, uprobes · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds, Masami Hiramatsu, Oleg Nesterov
From: "David A. Long" <redacted> Allow arches to write the opcode with a custom function. ARM needs to customize the swbp instruction depending on the condition code of the instruction it replaces. Signed-off-by: Rabin Vincent <redacted> Signed-off-by: David A. Long <redacted> --- include/linux/uprobes.h | 3 +++ kernel/events/uprobes.c | 20 +++++++++++++++----- 2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 6feae5d..9cd3b25 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h@@ -136,6 +136,9 @@ extern void arch_uprobe_abort_xol(struct arch_uprobe *aup, struct pt_regs *regs) extern bool __weak arch_uprobe_ignore(struct arch_uprobe *aup, struct pt_regs *regs); extern void __weak arch_uprobe_xol_copy(struct arch_uprobe *auprobe, void *vaddr); extern int __weak arch_uprobes_init(void); +extern void __weak arch_uprobe_write_opcode(struct arch_uprobe *auprobe, + void *vaddr, + uprobe_opcode_t opcode); #else /* !CONFIG_UPROBES */ struct uprobes_state { };
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 5004f6f..6a60eec 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c@@ -248,6 +248,12 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t * have fixed length instructions. */ +void __weak arch_uprobe_write_opcode(struct arch_uprobe *auprobe, void *vaddr, + uprobe_opcode_t opcode) +{ + memcpy(vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); +} + /* * write_opcode - write the opcode at a given virtual address. * @mm: the probed process address space.
@@ -260,8 +266,8 @@ static int verify_opcode(struct page *page, unsigned long vaddr, uprobe_opcode_t * For mm @mm, write the opcode at @vaddr. * Return 0 (success) or a negative errno. */ -static int write_opcode(struct mm_struct *mm, unsigned long vaddr, - uprobe_opcode_t opcode) +static int write_opcode(struct arch_uprobe *auprobe, struct mm_struct *mm, + unsigned long vaddr, uprobe_opcode_t opcode) { struct page *old_page, *new_page; struct vm_area_struct *vma;
@@ -285,7 +291,10 @@ retry: __SetPageUptodate(new_page); copy_highpage(new_page, old_page); - copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); + vaddr_new = kmap_atomic(new_page); + arch_uprobe_write_opcode(auprobe, vaddr_new + (vaddr & ~PAGE_MASK), + opcode); + kunmap_atomic(vaddr_new); ret = anon_vma_prepare(vma); if (ret)
@@ -314,7 +323,7 @@ put_old: */ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr) { - return write_opcode(mm, vaddr, UPROBE_SWBP_INSN); + return write_opcode(auprobe, mm, vaddr, UPROBE_SWBP_INSN); } /**
@@ -329,7 +338,8 @@ int __weak set_swbp(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned int __weak set_orig_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long vaddr) { - return write_opcode(mm, vaddr, *(uprobe_opcode_t *)auprobe->insn); + return write_opcode(auprobe, mm, vaddr, + *(uprobe_opcode_t *)auprobe->insn); } static int match_uprobe(struct uprobe *l, struct uprobe *r)
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1.8.1.2