From: Jan Beulich Date: Mon, 13 Jun 2022 07:53:23 +0000 (+0200) Subject: x86: replace global scratch buffer X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=95ff67183492ef847b181346a83485b38d0906c4;p=binutils-gdb.git x86: replace global scratch buffer With its movement to the stack, and with the subsequent desire to initialize the entire instr_info instances, this has become doubly inefficient. Individual users have better knowledge of how big a buffer they need, and in a number of cases going through an intermediate buffer can be avoided altogether. Having got confirmation that it wasn't intentional to print memory operand displacements with inconsistent style, print_displacement() is now using dis_style_address_offset consistently (eliminating the need for callers to pass in a style). While touching print_operand_value() also convert its "hex" parameter to bool. And while altering (and moving) oappend_immediate(), fold oappend_maybe_intel_with_style() into its only remaining caller. Finally where doing adjustments, use snprintf() in favor of sprintf(). --- diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c index d087b355103..5d851a269dc 100644 --- a/opcodes/i386-dis.c +++ b/opcodes/i386-dis.c @@ -51,9 +51,7 @@ static void oappend_with_style (instr_info *, const char *, static void oappend (instr_info *, const char *); static void append_seg (instr_info *); static void OP_indirE (instr_info *, int, int); -static void print_operand_value (instr_info *, char *, int, bfd_vma); static void OP_E_memory (instr_info *, int, int); -static void print_displacement (instr_info *, char *, bfd_vma); static void OP_E (instr_info *, int, int); static void OP_G (instr_info *, int, int); static bfd_vma get64 (instr_info *); @@ -170,7 +168,6 @@ struct instr_info char obuf[100]; char *obufp; char *mnemonicendp; - char scratchbuf[100]; unsigned char *start_codep; unsigned char *insn_codep; unsigned char *codep; @@ -9254,37 +9251,13 @@ get_sib (instr_info *ins, int sizeflag) ins->has_sib = false; } -/* Like oappend (below), but S is a string starting with '%' or '$'. In - Intel syntax, the '%' or '$' is elided. STYLE is used when displaying - this part of the output in the disassembler. - - This function should not be used directly from the general disassembler - code, instead the helpers oappend_register and oappend_immediate should - be called as appropriate. */ - -static void -oappend_maybe_intel_with_style (instr_info *ins, const char *s, - enum disassembler_style style) -{ - oappend_with_style (ins, s + ins->intel_syntax, style); -} - -/* Like oappend_maybe_intel_with_style above, but called when S is the - name of a register. */ +/* Like oappend (below), but S is a string starting with '%'. In + Intel syntax, the '%' is elided. */ static void oappend_register (instr_info *ins, const char *s) { - oappend_maybe_intel_with_style (ins, s, dis_style_register); -} - -/* Like oappend_maybe_intel_with_style above, but called when S represents - an immediate. */ - -static void -oappend_immediate (instr_info *ins, const char *s) -{ - oappend_maybe_intel_with_style (ins, s, dis_style_immediate); + oappend_with_style (ins, s + ins->intel_syntax, dis_style_register); } /* Wrap around a call to INS->info->fprintf_styled_func, printing FMT. @@ -10334,8 +10307,12 @@ static void OP_STi (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED) { - sprintf (ins->scratchbuf, "%%st(%d)", ins->modrm.rm); - oappend_register (ins, ins->scratchbuf); + char scratch[8]; + int res = snprintf (scratch, ARRAY_SIZE (scratch), "%%st(%d)", ins->modrm.rm); + + if (res < 0 || (size_t) res >= ARRAY_SIZE (scratch)) + abort (); + oappend_register (ins, scratch); } /* Capital letters in template are macros. */ @@ -10992,39 +10969,39 @@ OP_indirE (instr_info *ins, int bytemode, int sizeflag) } static void -print_operand_value (instr_info *ins, char *buf, int hex, bfd_vma disp) +print_operand_value (instr_info *ins, bool hex, bfd_vma disp, + enum disassembler_style style) { + char tmp[30]; + if (ins->address_mode == mode_64bit) { if (hex) { - char tmp[30]; int i; - buf[0] = '0'; - buf[1] = 'x'; + oappend_with_style (ins, "0x", style); sprintf_vma (tmp, disp); for (i = 0; tmp[i] == '0' && tmp[i + 1]; i++); - strcpy (buf + 2, tmp + i); + oappend_with_style (ins, tmp + i, style); } else { bfd_signed_vma v = disp; - char tmp[30]; int i; if (v < 0) { - *(buf++) = '-'; + oappend_char_with_style (ins, '-', style); v = -disp; /* Check for possible overflow on 0x8000000000000000. */ if (v < 0) { - strcpy (buf, "9223372036854775808"); + oappend_with_style (ins, "9223372036854775808", style); return; } } if (!v) { - strcpy (buf, "0"); + oappend_char_with_style (ins, '0', style); return; } @@ -11036,30 +11013,41 @@ print_operand_value (instr_info *ins, char *buf, int hex, bfd_vma disp) v /= 10; i++; } - strcpy (buf, tmp + 29 - i); + oappend_with_style (ins, tmp + 29 - i, style); } } else { if (hex) - sprintf (buf, "0x%x", (unsigned int) disp); + sprintf (tmp, "0x%x", (unsigned int) disp); else - sprintf (buf, "%d", (int) disp); + sprintf (tmp, "%d", (int) disp); + oappend_with_style (ins, tmp, style); } } +/* Like oappend, but called for immediate operands. */ + +static void +oappend_immediate (instr_info *ins, bfd_vma imm) +{ + if (!ins->intel_syntax) + oappend_char_with_style (ins, '$', dis_style_immediate); + print_operand_value (ins, true, imm, dis_style_immediate); +} + /* Put DISP in BUF as signed hex number. */ static void -print_displacement (instr_info *ins, char *buf, bfd_vma disp) +print_displacement (instr_info *ins, bfd_vma disp) { bfd_signed_vma val = disp; char tmp[30]; - int i, j = 0; + unsigned int i; if (val < 0) { - buf[j++] = '-'; + oappend_char_with_style (ins, '-', dis_style_address_offset); val = -disp; /* Check for possible overflow. */ @@ -11068,28 +11056,30 @@ print_displacement (instr_info *ins, char *buf, bfd_vma disp) switch (ins->address_mode) { case mode_64bit: - strcpy (buf + j, "0x8000000000000000"); + oappend_with_style (ins, "0x8000000000000000", + dis_style_address_offset); break; case mode_32bit: - strcpy (buf + j, "0x80000000"); + oappend_with_style (ins, "0x80000000", + dis_style_address_offset); break; case mode_16bit: - strcpy (buf + j, "0x8000"); + oappend_with_style (ins, "0x8000", + dis_style_address_offset); break; } return; } } - buf[j++] = '0'; - buf[j++] = 'x'; + oappend_with_style (ins, "0x", dis_style_address_offset); sprintf_vma (tmp, (bfd_vma) val); for (i = 0; tmp[i] == '0'; i++) continue; if (tmp[i] == '\0') i--; - strcpy (buf + j, tmp + i); + oappend_with_style (ins, tmp + i, dis_style_address_offset); } static void @@ -11729,11 +11719,9 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) if (ins->modrm.mod != 0 || base == 5) { if (havedisp || riprel) - print_displacement (ins, ins->scratchbuf, disp); + print_displacement (ins, disp); else - print_operand_value (ins, ins->scratchbuf, 1, disp); - oappend_with_style (ins, ins->scratchbuf, - dis_style_address_offset); + print_operand_value (ins, true, disp, dis_style_address_offset); if (riprel) { set_op (ins, disp, true); @@ -11792,9 +11780,8 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) : att_index32); oappend_char (ins, ins->scale_char); - sprintf (ins->scratchbuf, "%d", 1 << scale); - oappend_with_style (ins, ins->scratchbuf, - dis_style_immediate); + oappend_char_with_style (ins, '0' + (1 << scale), + dis_style_immediate); } } if (ins->intel_syntax @@ -11809,10 +11796,9 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) } if (havedisp) - print_displacement (ins, ins->scratchbuf, disp); + print_displacement (ins, disp); else - print_operand_value (ins, ins->scratchbuf, 1, disp); - oappend (ins, ins->scratchbuf); + print_operand_value (ins, true, disp, dis_style_address_offset); } oappend_char (ins, ins->close_char); @@ -11839,8 +11825,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) oappend_register (ins, att_names_seg[ds_reg - es_reg]); oappend (ins, ":"); } - print_operand_value (ins, ins->scratchbuf, 1, disp); - oappend (ins, ins->scratchbuf); + print_operand_value (ins, true, disp, dis_style_text); } } } @@ -11885,10 +11870,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) if (!ins->intel_syntax) if (ins->modrm.mod != 0 || ins->modrm.rm == 6) - { - print_displacement (ins, ins->scratchbuf, disp); - oappend (ins, ins->scratchbuf); - } + print_displacement (ins, disp); if (ins->modrm.mod != 0 || ins->modrm.rm != 6) { @@ -11906,8 +11888,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) disp = -disp; } - print_displacement (ins, ins->scratchbuf, disp); - oappend (ins, ins->scratchbuf); + print_displacement (ins, disp); } oappend_char (ins, ins->close_char); @@ -11919,8 +11900,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag) oappend_register (ins, att_names_seg[ds_reg - es_reg]); oappend (ins, ":"); } - print_operand_value (ins, ins->scratchbuf, 1, disp & 0xffff); - oappend (ins, ins->scratchbuf); + print_operand_value (ins, true, disp & 0xffff, dis_style_text); } } if (ins->vex.b) @@ -12274,10 +12254,7 @@ OP_I (instr_info *ins, int bytemode, int sizeflag) } op &= mask; - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, op); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, op); } static void @@ -12292,10 +12269,7 @@ OP_I64 (instr_info *ins, int bytemode, int sizeflag) USED_REX (REX_W); - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, get64 (ins)); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, get64 (ins)); } static void @@ -12346,9 +12320,7 @@ OP_sI (instr_info *ins, int bytemode, int sizeflag) return; } - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, op); - oappend_immediate (ins, ins->scratchbuf); + oappend_immediate (ins, op); } static void @@ -12398,8 +12370,7 @@ OP_J (instr_info *ins, int bytemode, int sizeflag) disp = ((ins->start_pc + (ins->codep - ins->start_codep) + disp) & mask) | segment; set_op (ins, disp, false); - print_operand_value (ins, ins->scratchbuf, 1, disp); - oappend (ins, ins->scratchbuf); + print_operand_value (ins, true, disp, dis_style_text); } static void @@ -12414,7 +12385,8 @@ OP_SEG (instr_info *ins, int bytemode, int sizeflag) static void OP_DIR (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag) { - int seg, offset; + int seg, offset, res; + char scratch[24]; if (sizeflag & DFLAG) { @@ -12427,11 +12399,13 @@ OP_DIR (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag) seg = get16 (ins); } ins->used_prefixes |= (ins->prefixes & PREFIX_DATA); - if (ins->intel_syntax) - sprintf (ins->scratchbuf, "0x%x:0x%x", seg, offset); - else - sprintf (ins->scratchbuf, "$0x%x,$0x%x", seg, offset); - oappend (ins, ins->scratchbuf); + + res = snprintf (scratch, ARRAY_SIZE (scratch), + ins->intel_syntax ? "0x%x:0x%x" : "$0x%x,$0x%x", + seg, offset); + if (res < 0 || (size_t) res >= ARRAY_SIZE (scratch)) + abort (); + oappend (ins, scratch); } static void @@ -12456,8 +12430,7 @@ OP_OFF (instr_info *ins, int bytemode, int sizeflag) oappend (ins, ":"); } } - print_operand_value (ins, ins->scratchbuf, 1, off); - oappend_with_style (ins, ins->scratchbuf, dis_style_address_offset); + print_operand_value (ins, true, off, dis_style_address_offset); } static void @@ -12486,8 +12459,7 @@ OP_OFF64 (instr_info *ins, int bytemode, int sizeflag) oappend (ins, ":"); } } - print_operand_value (ins, ins->scratchbuf, 1, off); - oappend_with_style (ins, ins->scratchbuf, dis_style_address_offset); + print_operand_value (ins, true, off, dis_style_address_offset); } static void @@ -12568,7 +12540,9 @@ static void OP_C (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED) { - int add; + int add, res; + char scratch[8]; + if (ins->rex & REX_R) { USED_REX (REX_R); @@ -12582,33 +12556,44 @@ OP_C (instr_info *ins, int dummy ATTRIBUTE_UNUSED, } else add = 0; - sprintf (ins->scratchbuf, "%%cr%d", ins->modrm.reg + add); - oappend_register (ins, ins->scratchbuf); + res = snprintf (scratch, ARRAY_SIZE (scratch), "%%cr%d", + ins->modrm.reg + add); + if (res < 0 || (size_t) res >= ARRAY_SIZE (scratch)) + abort (); + oappend_register (ins, scratch); } static void OP_D (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED) { - int add; + int add, res; + char scratch[8]; + USED_REX (REX_R); if (ins->rex & REX_R) add = 8; else add = 0; - if (ins->intel_syntax) - sprintf (ins->scratchbuf, "dr%d", ins->modrm.reg + add); - else - sprintf (ins->scratchbuf, "%%db%d", ins->modrm.reg + add); - oappend (ins, ins->scratchbuf); + res = snprintf (scratch, ARRAY_SIZE (scratch), + ins->intel_syntax ? "dr%d" : "%%db%d", + ins->modrm.reg + add); + if (res < 0 || (size_t) res >= ARRAY_SIZE (scratch)) + abort (); + oappend (ins, scratch); } static void OP_T (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED) { - sprintf (ins->scratchbuf, "%%tr%d", ins->modrm.reg); - oappend_register (ins, ins->scratchbuf); + int res; + char scratch[8]; + + res = snprintf (scratch, ARRAY_SIZE (scratch), "%%tr%d", ins->modrm.reg); + if (res < 0 || (size_t) res >= ARRAY_SIZE (scratch)) + abort (); + oappend_register (ins, scratch); } static void @@ -13060,10 +13045,7 @@ CMP_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, else { /* We have a reserved extension byte. Output it directly. */ - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, cmp_type); } } @@ -13515,9 +13497,7 @@ static void OP_VexI4 (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, int sizeflag ATTRIBUTE_UNUSED) { - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, ins->codep[-1] & 0xf); - oappend_immediate (ins, ins->scratchbuf); + oappend_immediate (ins, ins->codep[-1] & 0xf); } static void @@ -13560,10 +13540,7 @@ VPCMP_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, else { /* We have a reserved extension byte. Output it directly. */ - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, cmp_type); } } @@ -13612,10 +13589,7 @@ VPCOM_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, else { /* We have a reserved extension byte. Output it directly. */ - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, cmp_type); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, cmp_type); } } @@ -13660,10 +13634,7 @@ PCLMUL_Fixup (instr_info *ins, int bytemode ATTRIBUTE_UNUSED, else { /* We have a reserved extension byte. Output it directly. */ - ins->scratchbuf[0] = '$'; - print_operand_value (ins, ins->scratchbuf + 1, 1, pclmul_type); - oappend_immediate (ins, ins->scratchbuf); - ins->scratchbuf[0] = '\0'; + oappend_immediate (ins, pclmul_type); } }