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Message-Id: <1251340337-5640-5-git-send-email-fweisbec@gmail.com>
Date: Thu, 27 Aug 2009 04:32:03 +0200
From: Frederic Weisbecker <fweisbec@...il.com>
To: Ingo Molnar <mingo@...e.hu>
Cc: LKML <linux-kernel@...r.kernel.org>,
Masami Hiramatsu <mhiramat@...hat.com>,
Ananth N Mavinakayanahalli <ananth@...ibm.com>,
Avi Kivity <avi@...hat.com>, Andi Kleen <ak@...ux.intel.com>,
Christoph Hellwig <hch@...radead.org>,
"Frank Ch. Eigler" <fche@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...e.hu>,
Jason Baron <jbaron@...hat.com>,
Jim Keniston <jkenisto@...ibm.com>,
"K.Prasad" <prasad@...ux.vnet.ibm.com>,
Lai Jiangshan <laijs@...fujitsu.com>,
Li Zefan <lizf@...fujitsu.com>,
Przemysław Pawełczyk
<przemyslaw@...elczyk.it>, Roland McGrath <roland@...hat.com>,
Sam Ravnborg <sam@...nborg.org>,
Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
Steven Rostedt <rostedt@...dmis.org>,
Tom Zanussi <tzanussi@...il.com>,
Vegard Nossum <vegard.nossum@...il.com>,
Frederic Weisbecker <fweisbec@...il.com>
Subject: [PATCH 04/18] kprobes: Cleanup fix_riprel() using insn decoder on x86
From: Masami Hiramatsu <mhiramat@...hat.com>
Cleanup fix_riprel() in arch/x86/kernel/kprobes.c by using the new x86
instruction decoder instead of using comparisons with raw ad hoc numeric
opcodes.
Signed-off-by: Masami Hiramatsu <mhiramat@...hat.com>
Cc: Ananth N Mavinakayanahalli <ananth@...ibm.com>
Cc: Avi Kivity <avi@...hat.com>
Cc: Andi Kleen <ak@...ux.intel.com>
Cc: Christoph Hellwig <hch@...radead.org>
Cc: Frank Ch. Eigler <fche@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Ingo Molnar <mingo@...e.hu>
Cc: Jason Baron <jbaron@...hat.com>
Cc: Jim Keniston <jkenisto@...ibm.com>
Cc: K.Prasad <prasad@...ux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@...fujitsu.com>
Cc: Li Zefan <lizf@...fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@...elczyk.it>
Cc: Roland McGrath <roland@...hat.com>
Cc: Sam Ravnborg <sam@...nborg.org>
Cc: Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@...dmis.org>
Cc: Tom Zanussi <tzanussi@...il.com>
Cc: Vegard Nossum <vegard.nossum@...il.com>
LKML-Reference: <20090813203436.31965.34374.stgit@...alhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
---
arch/x86/kernel/kprobes.c | 128 ++++++++-------------------------------------
1 files changed, 23 insertions(+), 105 deletions(-)
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index aa15f3e..16ae961 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -108,50 +108,6 @@ static const u32 twobyte_is_boostable[256 / 32] = {
/* ----------------------------------------------- */
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
};
-static const u32 onebyte_has_modrm[256 / 32] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */
- W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */
- W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */
- W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */
- W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */
- W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
- W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */
- W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */
- W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
- W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */
- W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */
- W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */
- W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */
- W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
- W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */
- W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-static const u32 twobyte_has_modrm[256 / 32] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */
- W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */
- W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */
- W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */
- W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */
- W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */
- W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */
- W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */
- W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */
- W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */
- W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */
- W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */
- W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */
- W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */
- W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */
- W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
#undef W
struct kretprobe_blackpoint kretprobe_blacklist[] = {
@@ -348,68 +304,30 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
static void __kprobes fix_riprel(struct kprobe *p)
{
#ifdef CONFIG_X86_64
- u8 *insn = p->ainsn.insn;
- s64 disp;
- int need_modrm;
-
- /* Skip legacy instruction prefixes. */
- while (1) {
- switch (*insn) {
- case 0x66:
- case 0x67:
- case 0x2e:
- case 0x3e:
- case 0x26:
- case 0x64:
- case 0x65:
- case 0x36:
- case 0xf0:
- case 0xf3:
- case 0xf2:
- ++insn;
- continue;
- }
- break;
- }
+ struct insn insn;
+ kernel_insn_init(&insn, p->ainsn.insn);
- /* Skip REX instruction prefix. */
- if (is_REX_prefix(insn))
- ++insn;
-
- if (*insn == 0x0f) {
- /* Two-byte opcode. */
- ++insn;
- need_modrm = test_bit(*insn,
- (unsigned long *)twobyte_has_modrm);
- } else
- /* One-byte opcode. */
- need_modrm = test_bit(*insn,
- (unsigned long *)onebyte_has_modrm);
-
- if (need_modrm) {
- u8 modrm = *++insn;
- if ((modrm & 0xc7) == 0x05) {
- /* %rip+disp32 addressing mode */
- /* Displacement follows ModRM byte. */
- ++insn;
- /*
- * The copied instruction uses the %rip-relative
- * addressing mode. Adjust the displacement for the
- * difference between the original location of this
- * instruction and the location of the copy that will
- * actually be run. The tricky bit here is making sure
- * that the sign extension happens correctly in this
- * calculation, since we need a signed 32-bit result to
- * be sign-extended to 64 bits when it's added to the
- * %rip value and yield the same 64-bit result that the
- * sign-extension of the original signed 32-bit
- * displacement would have given.
- */
- disp = (u8 *) p->addr + *((s32 *) insn) -
- (u8 *) p->ainsn.insn;
- BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
- *(s32 *)insn = (s32) disp;
- }
+ if (insn_rip_relative(&insn)) {
+ s64 newdisp;
+ u8 *disp;
+ insn_get_displacement(&insn);
+ /*
+ * The copied instruction uses the %rip-relative addressing
+ * mode. Adjust the displacement for the difference between
+ * the original location of this instruction and the location
+ * of the copy that will actually be run. The tricky bit here
+ * is making sure that the sign extension happens correctly in
+ * this calculation, since we need a signed 32-bit result to
+ * be sign-extended to 64 bits when it's added to the %rip
+ * value and yield the same 64-bit result that the sign-
+ * extension of the original signed 32-bit displacement would
+ * have given.
+ */
+ newdisp = (u8 *) p->addr + (s64) insn.displacement.value -
+ (u8 *) p->ainsn.insn;
+ BUG_ON((s64) (s32) newdisp != newdisp); /* Sanity check. */
+ disp = (u8 *) p->ainsn.insn + insn_offset_displacement(&insn);
+ *(s32 *) disp = (s32) newdisp;
}
#endif
}
--
1.6.2.3
--
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