Skip to content

L
linux
Commit 611b1597 authored by Pekka Paalanen's avatar Pekka Paalanen Committed by Ingo Molnar
Browse files
Options

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: default avatarPekka 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: default avatarIngo Molnar <mingo@elte.hu>
parent 5f87f112
Show whitespace changes
Inline Side-by-side
Showing with 84 additions and 37 deletions
arch/x86/mm/pf_in.c
View file @ 611b1597
...@@ -79,25 +79,34 @@ static unsigned int mw32[] = { 0xC7 }; ...@@ -79,25 +79,34 @@ static unsigned int mw32[] = { 0xC7 };
static unsigned int mw64[] = { 0x89, 0x8B }; static unsigned int mw64[] = { 0x89, 0x8B };
#endif /* not __i386__ */ #endif /* not __i386__ */
static int skip_prefix(unsigned char *addr, int *shorted, int *enlarged, struct prefix_bits {
int *rexr) 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; int i;
unsigned char *p = addr; unsigned char *p = addr;
*shorted = 0; prf->shorted = 0;
*enlarged = 0; prf->enlarged = 0;
*rexr = 0; prf->rexr = 0;
prf->rex = 0;
restart: restart:
for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) { for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
if (*p == prefix_codes[i]) { if (*p == prefix_codes[i]) {
if (*p == 0x66) if (*p == 0x66)
*shorted = 1; prf->shorted = 1;
#ifdef __amd64__ #ifdef __amd64__
if ((*p & 0xf8) == 0x48) if ((*p & 0xf8) == 0x48)
*enlarged = 1; prf->enlarged = 1;
if ((*p & 0xf4) == 0x44) if ((*p & 0xf4) == 0x44)
*rexr = 1; prf->rexr = 1;
if ((*p & 0xf0) == 0x40)
prf->rex = 1;
#endif #endif
p++; p++;
goto restart; goto restart;
...@@ -135,12 +144,12 @@ enum reason_type get_ins_type(unsigned long ins_addr) ...@@ -135,12 +144,12 @@ enum reason_type get_ins_type(unsigned long ins_addr)
{ {
unsigned int opcode; unsigned int opcode;
unsigned char *p; unsigned char *p;
int shorted, enlarged, rexr; struct prefix_bits prf;
int i; int i;
enum reason_type rv = OTHERS; enum reason_type rv = OTHERS;
p = (unsigned char *)ins_addr; p = (unsigned char *)ins_addr;
p += skip_prefix(p, &shorted, &enlarged, &rexr); p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode); p += get_opcode(p, &opcode);
CHECK_OP_TYPE(opcode, reg_rop, REG_READ); CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
...@@ -156,10 +165,11 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr) ...@@ -156,10 +165,11 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr)
{ {
unsigned int opcode; unsigned int opcode;
unsigned char *p; unsigned char *p;
int i, shorted, enlarged, rexr; struct prefix_bits prf;
int i;
p = (unsigned char *)ins_addr; p = (unsigned char *)ins_addr;
p += skip_prefix(p, &shorted, &enlarged, &rexr); p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode); p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(rw8); i++) for (i = 0; i < ARRAY_SIZE(rw8); i++)
...@@ -168,7 +178,7 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr) ...@@ -168,7 +178,7 @@ static unsigned int get_ins_reg_width(unsigned long ins_addr)
for (i = 0; i < ARRAY_SIZE(rw32); i++) for (i = 0; i < ARRAY_SIZE(rw32); i++)
if (rw32[i] == opcode) 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); printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
return 0; return 0;
...@@ -178,10 +188,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr) ...@@ -178,10 +188,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr)
{ {
unsigned int opcode; unsigned int opcode;
unsigned char *p; unsigned char *p;
int i, shorted, enlarged, rexr; struct prefix_bits prf;
int i;
p = (unsigned char *)ins_addr; p = (unsigned char *)ins_addr;
p += skip_prefix(p, &shorted, &enlarged, &rexr); p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode); p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(mw8); i++) for (i = 0; i < ARRAY_SIZE(mw8); i++)
...@@ -194,11 +205,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr) ...@@ -194,11 +205,11 @@ unsigned int get_ins_mem_width(unsigned long ins_addr)
for (i = 0; i < ARRAY_SIZE(mw32); i++) for (i = 0; i < ARRAY_SIZE(mw32); i++)
if (mw32[i] == opcode) if (mw32[i] == opcode)
return shorted ? 2 : 4; return prf.shorted ? 2 : 4;
for (i = 0; i < ARRAY_SIZE(mw64); i++) for (i = 0; i < ARRAY_SIZE(mw64); i++)
if (mw64[i] == opcode) 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); printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
return 0; return 0;
...@@ -238,7 +249,7 @@ enum { ...@@ -238,7 +249,7 @@ enum {
#endif #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; unsigned char *rv = NULL;
...@@ -255,18 +266,6 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs) ...@@ -255,18 +266,6 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs)
case arg_DL: case arg_DL:
rv = (unsigned char *)&regs->dx; rv = (unsigned char *)&regs->dx;
break; 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__ #ifdef __amd64__
case arg_R8: case arg_R8:
rv = (unsigned char *)&regs->r8; rv = (unsigned char *)&regs->r8;
...@@ -294,9 +293,55 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs) ...@@ -294,9 +293,55 @@ static unsigned char *get_reg_w8(int no, struct pt_regs *regs)
break; break;
#endif #endif
default: default:
printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
break; 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; return rv;
} }
...@@ -368,11 +413,12 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs) ...@@ -368,11 +413,12 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
unsigned char mod_rm; unsigned char mod_rm;
int reg; int reg;
unsigned char *p; unsigned char *p;
int i, shorted, enlarged, rexr; struct prefix_bits prf;
int i;
unsigned long rv; unsigned long rv;
p = (unsigned char *)ins_addr; p = (unsigned char *)ins_addr;
p += skip_prefix(p, &shorted, &enlarged, &rexr); p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode); p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(reg_rop); i++) for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
if (reg_rop[i] == opcode) { if (reg_rop[i] == opcode) {
...@@ -392,10 +438,10 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs) ...@@ -392,10 +438,10 @@ unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
do_work: do_work:
mod_rm = *p; 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)) { switch (get_ins_reg_width(ins_addr)) {
case 1: case 1:
return *get_reg_w8(reg, regs); return *get_reg_w8(reg, prf.rex, regs);
case 2: case 2:
return *(unsigned short *)get_reg_w32(reg, regs); return *(unsigned short *)get_reg_w32(reg, regs);
...@@ -422,11 +468,12 @@ unsigned long get_ins_imm_val(unsigned long ins_addr) ...@@ -422,11 +468,12 @@ unsigned long get_ins_imm_val(unsigned long ins_addr)
unsigned char mod_rm; unsigned char mod_rm;
unsigned char mod; unsigned char mod;
unsigned char *p; unsigned char *p;
int i, shorted, enlarged, rexr; struct prefix_bits prf;
int i;
unsigned long rv; unsigned long rv;
p = (unsigned char *)ins_addr; p = (unsigned char *)ins_addr;
p += skip_prefix(p, &shorted, &enlarged, &rexr); p += skip_prefix(p, &prf);
p += get_opcode(p, &opcode); p += get_opcode(p, &opcode);
for (i = 0; i < ARRAY_SIZE(imm_wop); i++) for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
if (imm_wop[i] == opcode) { if (imm_wop[i] == opcode) {
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7