[PATCH 4/7] uprobes/x86: Kill the "ia32_compat" check in handle_riprel_insn(), remove "mm" arg

From: Oleg Nesterov
Date: Mon Mar 31 2014 - 16:46:22 EST


Kill the "mm->context.ia32_compat" check in handle_riprel_insn(), if
it is true insn_rip_relative() must return false. validate_insn_bits()
passed "ia32_compat" as !x86_64 to insn_init(), and insn_rip_relative()
checks insn->x86_64.

Also, remove the no longer needed "struct mm_struct *mm" argument and
the unnecessary "return" at the end.

Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
---
arch/x86/kernel/uprobes.c | 10 +++-------
1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index d72dfbf..382a69d 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -253,14 +253,11 @@ static int validate_insn_32bits(struct arch_uprobe *auprobe, struct insn *insn)
* - The displacement is always 4 bytes.
*/
static void
-handle_riprel_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn)
{
u8 *cursor;
u8 reg;

- if (mm->context.ia32_compat)
- return;
-
if (!insn_rip_relative(insn))
return;

@@ -314,7 +311,6 @@ handle_riprel_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, struct ins
cursor++;
memmove(cursor, cursor + insn->displacement.nbytes, insn->immediate.nbytes);
}
- return;
}

static int validate_insn_64bits(struct arch_uprobe *auprobe, struct insn *insn)
@@ -343,7 +339,7 @@ static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm,
return validate_insn_64bits(auprobe, insn);
}
#else /* 32-bit: */
-static void handle_riprel_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn)
+static void handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn)
{
/* No RIP-relative addressing on 32-bit */
}
@@ -406,7 +402,7 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
}
/* fall through */
default:
- handle_riprel_insn(auprobe, mm, &insn);
+ handle_riprel_insn(auprobe, &insn);
}

if (fix_ip)
--
1.5.5.1

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