Commit-ID: 83cd591485e558ab70aed45ce7261ce3f5ee8746
Gitweb: http://git.kernel.org/tip/83cd591485e558ab70aed45ce7261ce3f5ee8746
Author: Oleg Nesterov <oleg@xxxxxxxxxx>
AuthorDate: Fri, 25 Apr 2014 18:53:32 +0200
Committer: Oleg Nesterov <oleg@xxxxxxxxxx>
CommitDate: Wed, 30 Apr 2014 19:10:40 +0200
uprobes/x86: Cleanup the usage of UPROBE_FIX_IP/UPROBE_FIX_CALL
Now that UPROBE_FIX_IP/UPROBE_FIX_CALL are mutually exclusive we can
use a single "fix_ip_or_call" enum instead of 2 fix_* booleans. This
way the logic looks more understandable and clean to me.
While at it, join "case 0xea" with other "ip is correct" ret/lret cases.
Also change default_post_xol_op() to use "else if" for the same reason.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
arch/x86/kernel/uprobes.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 5bcce85..d2792e8 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -424,10 +424,9 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs
long correction = (long)(utask->vaddr - utask->xol_vaddr);
handle_riprel_post_xol(auprobe, regs, &correction);
- if (auprobe->def.fixups & UPROBE_FIX_IP)
+ if (auprobe->def.fixups & UPROBE_FIX_IP) {
regs->ip += correction;
-
- if (auprobe->def.fixups & UPROBE_FIX_CALL) {
+ } else if (auprobe->def.fixups & UPROBE_FIX_CALL) {
regs->sp += sizeof_long();
if (push_ret_address(regs, utask->vaddr + auprobe->def.ilen))
return -ERESTART;
@@ -623,7 +622,7 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn)
int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, unsigned long addr)
{
struct insn insn;
- bool fix_ip = true, fix_call = false;
+ u8 fix_ip_or_call = UPROBE_FIX_IP;
int ret;
ret = uprobe_init_insn(auprobe, &insn, is_64bit_mm(mm));
@@ -647,21 +646,20 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
case 0xcb:
case 0xc2:
case 0xca:
- fix_ip = false;
+ case 0xea: /* jmp absolute -- ip is correct */
+ fix_ip_or_call = 0;
break;
case 0x9a: /* call absolute - Fix return addr, not ip */
- fix_call = true;
- fix_ip = false;
- break;
- case 0xea: /* jmp absolute -- ip is correct */
- fix_ip = false;
+ fix_ip_or_call = UPROBE_FIX_CALL;
break;
case 0xff:
switch (MODRM_REG(&insn)) {
case 2: case 3: /* call or lcall, indirect */
- fix_call = true;
+ fix_ip_or_call = UPROBE_FIX_CALL;
+ break;
case 4: case 5: /* jmp or ljmp, indirect */
- fix_ip = false;
+ fix_ip_or_call = 0;
+ break;
}
/* fall through */
default:
@@ -669,10 +667,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
}
auprobe->def.ilen = insn.length;
- if (fix_ip)
- auprobe->def.fixups |= UPROBE_FIX_IP;
- if (fix_call)
- auprobe->def.fixups |= UPROBE_FIX_CALL;
+ auprobe->def.fixups |= fix_ip_or_call;
auprobe->ops = &default_xol_ops;
return 0;
--
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