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kprobes: Cleanup fix_riprel() using insn decoder on x86

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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@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Przemysław Pawełczyk <przemyslaw@pawelczyk.it>
Cc: Roland McGrath <roland@redhat.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
LKML-Reference: <20090813203436.31965.34374.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
This commit is contained in:
Masami Hiramatsu
2009-08-13 16:34:36 -04:00
committed by Frederic Weisbecker
parent b46b3d70c9
commit 89ae465b0e
1 changed files with 23 additions and 105 deletions
Download Patch File Download Diff File Expand all files Collapse all files

122
arch/x86/kernel/kprobes.c
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@@ -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 */ /* 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 #undef W
struct kretprobe_blackpoint kretprobe_blacklist[] = { 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) static void __kprobes fix_riprel(struct kprobe *p)
{ {
#ifdef CONFIG_X86_64 #ifdef CONFIG_X86_64
u8 *insn = p->ainsn.insn; struct insn insn;
s64 disp; kernel_insn_init(&insn, p->ainsn.insn);
int need_modrm;
/* Skip legacy instruction prefixes. */ if (insn_rip_relative(&insn)) {
while (1) { s64 newdisp;
switch (*insn) { u8 *disp;
case 0x66: insn_get_displacement(&insn);
case 0x67:
case 0x2e:
case 0x3e:
case 0x26:
case 0x64:
case 0x65:
case 0x36:
case 0xf0:
case 0xf3:
case 0xf2:
++insn;
continue;
}
break;
}
/* 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 * The copied instruction uses the %rip-relative addressing
* addressing mode. Adjust the displacement for the * mode. Adjust the displacement for the difference between
* difference between the original location of this * the original location of this instruction and the location
* instruction and the location of the copy that will * of the copy that will actually be run. The tricky bit here
* actually be run. The tricky bit here is making sure * is making sure that the sign extension happens correctly in
* that the sign extension happens correctly in this * this calculation, since we need a signed 32-bit result to
* calculation, since we need a signed 32-bit result to * be sign-extended to 64 bits when it's added to the %rip
* be sign-extended to 64 bits when it's added to the * value and yield the same 64-bit result that the sign-
* %rip value and yield the same 64-bit result that the * extension of the original signed 32-bit displacement would
* sign-extension of the original signed 32-bit * have given.
* displacement would have given.
*/ */
disp = (u8 *) p->addr + *((s32 *) insn) - newdisp = (u8 *) p->addr + (s64) insn.displacement.value -
(u8 *) p->ainsn.insn; (u8 *) p->ainsn.insn;
BUG_ON((s64) (s32) disp != disp); /* Sanity check. */ BUG_ON((s64) (s32) newdisp != newdisp); /* Sanity check. */
*(s32 *)insn = (s32) disp; disp = (u8 *) p->ainsn.insn + insn_offset_displacement(&insn);
} *(s32 *) disp = (s32) newdisp;
} }
#endif #endif
} }