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authorPekka Paalanen <pq@iki.fi>2008-07-21 19:49:56 +0400
committerIngo Molnar <mingo@elte.hu>2008-10-14 12:33:50 +0400
commit611b1597680dd4a57896bcca1af0484be463c55e (patch)
tree29356a233cad80a0bcf8c42c966b782726ac9892 /arch/x86/mm/pf_in.c
parent5f87f1121895dc09d2d1c1db5f14af6aa4ce3e94 (diff)
downloadlinux-611b1597680dd4a57896bcca1af0484be463c55e.tar.xz
x86: fix mmiotrace 8-bit register decoding
When SIL, DIL, BPL or SPL registers were used in MMIO, the datum was extracted from AH, BH, CH, or DH, which are incorrect. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: "Vegard Nossum" <vegard.nossum@gmail.com> Cc: "Steven Rostedt" <srostedt@redhat.com> Cc: proski@gnu.org Cc: "Pekka Enberg" <penberg@cs.helsinki.fi> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/pf_in.c')
-rw-r--r--arch/x86/mm/pf_in.c121
1 files changed, 84 insertions, 37 deletions
diff --git a/arch/x86/mm/pf_in.c b/arch/x86/mm/pf_in.c
index efa1911e20ca..df3d5c861cda 100644
--- a/arch/x86/mm/pf_in.c
+++ b/arch/x86/mm/pf_in.c
@@ -79,25 +79,34 @@ static unsigned int mw32[] = { 0xC7 };
static unsigned int mw64[] = { 0x89, 0x8B };
#endif /* not __i386__ */
-static int skip_prefix(unsigned char *addr, int *shorted, int *enlarged,
- int *rexr)
+struct prefix_bits {
+ unsigned shorted:1;
+ unsigned enlarged:1;
+ unsigned rexr:1;
+ unsigned rex:1;
+};
+
+static int skip_prefix(unsigned char *addr, struct prefix_bits *prf)
{
int i;
unsigned char *p = addr;
- *shorted = 0;
- *enlarged = 0;
- *rexr = 0;
+ prf->shorted = 0;
+ prf->enlarged = 0;
+ prf->rexr = 0;
+ prf->rex = 0;
restart:
for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
if (*p == prefix_codes[i]) {
if (*p == 0x66)
- *shorted = 1;
+ prf->shorted = 1;
#ifdef __amd64__
if ((*p & 0xf8) == 0x48)
- *enlarged = 1;
+ prf->enlarged = 1;
if ((*p & 0xf4) == 0x44)
- *rexr = 1;
+ prf->rexr = 1;
+ if ((*p & 0xf0) == 0x40)
+ prf->rex = 1;
#endif
p++;
goto restart;
@@ -135,12 +144,12 @@ enum reason_type get_ins_type(unsigned long ins_addr)
{
unsigned int opcode;
unsigned char *p;
- int shorted, enlarged, rexr;
+ struct prefix_bits prf;
int i;
enum reason_type rv = OTHERS;
p = (unsigned char *)ins_addr;
- p += skip_prefix(p, &shorted, &enlarged, &rexr);
+ p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode);
CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
@@ -156,10 +165,11 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr)
{
unsigned int opcode;
unsigned char *p;
- int i, shorted, enlarged, rexr;
+ struct prefix_bits prf;
+ int i;
p = (unsigned char *)ins_addr;
- p += skip_prefix(p, &shorted, &enlarged, &rexr);
+ p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(rw8); i++)
@@ -168,7 +178,7 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr)
for (i = 0; i < ARRAY_SIZE(rw32); i++)
if (rw32[i] == opcode)
- return (shorted ? 2 : (enlarged ? 8 : 4));
+ return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
return 0;
@@ -178,10 +188,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr)
{
unsigned int opcode;
unsigned char *p;
- int i, shorted, enlarged, rexr;
+ struct prefix_bits prf;
+ int i;
p = (unsigned char *)ins_addr;
- p += skip_prefix(p, &shorted, &enlarged, &rexr);
+ p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(mw8); i++)
@@ -194,11 +205,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr)
for (i = 0; i < ARRAY_SIZE(mw32); i++)
if (mw32[i] == opcode)
- return shorted ? 2 : 4;
+ return prf.shorted ? 2 : 4;
for (i = 0; i < ARRAY_SIZE(mw64); i++)
if (mw64[i] == opcode)
- return shorted ? 2 : (enlarged ? 8 : 4);
+ return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
return 0;
@@ -238,7 +249,7 @@ enum {
#endif
};
-static unsigned char *get_reg_w8(int no, struct pt_regs *regs)
+static unsigned char *get_reg_w8(int no, int rex, struct pt_regs *regs)
{
unsigned char *rv = NULL;
@@ -255,18 +266,6 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs)
case arg_DL:
rv = (unsigned char *)&regs->dx;
break;
- case arg_AH:
- rv = 1 + (unsigned char *)&regs->ax;
- break;
- case arg_BH:
- rv = 1 + (unsigned char *)&regs->bx;
- break;
- case arg_CH:
- rv = 1 + (unsigned char *)&regs->cx;
- break;
- case arg_DH:
- rv = 1 + (unsigned char *)&regs->dx;
- break;
#ifdef __amd64__
case arg_R8:
rv = (unsigned char *)&regs->r8;
@@ -294,9 +293,55 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs)
break;
#endif
default:
- printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
break;
}
+
+ if (rv)
+ return rv;
+
+ if (rex) {
+ /*
+ * If REX prefix exists, access low bytes of SI etc.
+ * instead of AH etc.
+ */
+ switch (no) {
+ case arg_SI:
+ rv = (unsigned char *)&regs->si;
+ break;
+ case arg_DI:
+ rv = (unsigned char *)&regs->di;
+ break;
+ case arg_BP:
+ rv = (unsigned char *)&regs->bp;
+ break;
+ case arg_SP:
+ rv = (unsigned char *)&regs->sp;
+ break;
+ default:
+ break;
+ }
+ } else {
+ switch (no) {
+ case arg_AH:
+ rv = 1 + (unsigned char *)&regs->ax;
+ break;
+ case arg_BH:
+ rv = 1 + (unsigned char *)&regs->bx;
+ break;
+ case arg_CH:
+ rv = 1 + (unsigned char *)&regs->cx;
+ break;
+ case arg_DH:
+ rv = 1 + (unsigned char *)&regs->dx;
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (!rv)
+ printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
+
return rv;
}
@@ -368,11 +413,12 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
unsigned char mod_rm;
int reg;
unsigned char *p;
- int i, shorted, enlarged, rexr;
+ struct prefix_bits prf;
+ int i;
unsigned long rv;
p = (unsigned char *)ins_addr;
- p += skip_prefix(p, &shorted, &enlarged, &rexr);
+ p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
if (reg_rop[i] == opcode) {
@@ -392,10 +438,10 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
do_work:
mod_rm = *p;
- reg = ((mod_rm >> 3) & 0x7) | (rexr << 3);
+ reg = ((mod_rm >> 3) & 0x7) | (prf.rexr << 3);
switch (get_ins_reg_width(ins_addr)) {
case 1:
- return *get_reg_w8(reg, regs);
+ return *get_reg_w8(reg, prf.rex, regs);
case 2:
return *(unsigned short *)get_reg_w32(reg, regs);
@@ -422,11 +468,12 @@ unsigned long get_ins_imm_val(unsigned long ins_addr)
unsigned char mod_rm;
unsigned char mod;
unsigned char *p;
- int i, shorted, enlarged, rexr;
+ struct prefix_bits prf;
+ int i;
unsigned long rv;
p = (unsigned char *)ins_addr;
- p += skip_prefix(p, &shorted, &enlarged, &rexr);
+ p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
if (imm_wop[i] == opcode) {