From 611b1597680dd4a57896bcca1af0484be463c55e Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Mon, 21 Jul 2008 18:49:56 +0300 Subject: 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 Cc: "Vegard Nossum" Cc: "Steven Rostedt" Cc: proski@gnu.org Cc: "Pekka Enberg" Signed-off-by: Ingo Molnar --- arch/x86/mm/pf_in.c | 121 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 84 insertions(+), 37 deletions(-) (limited to 'arch/x86/mm/pf_in.c') 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 *)®s->dx; break; - case arg_AH: - rv = 1 + (unsigned char *)®s->ax; - break; - case arg_BH: - rv = 1 + (unsigned char *)®s->bx; - break; - case arg_CH: - rv = 1 + (unsigned char *)®s->cx; - break; - case arg_DH: - rv = 1 + (unsigned char *)®s->dx; - break; #ifdef __amd64__ case arg_R8: rv = (unsigned char *)®s->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 *)®s->si; + break; + case arg_DI: + rv = (unsigned char *)®s->di; + break; + case arg_BP: + rv = (unsigned char *)®s->bp; + break; + case arg_SP: + rv = (unsigned char *)®s->sp; + break; + default: + break; + } + } else { + switch (no) { + case arg_AH: + rv = 1 + (unsigned char *)®s->ax; + break; + case arg_BH: + rv = 1 + (unsigned char *)®s->bx; + break; + case arg_CH: + rv = 1 + (unsigned char *)®s->cx; + break; + case arg_DH: + rv = 1 + (unsigned char *)®s->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) { -- cgit v1.2.3