* [binutils-gdb] x86: change fetch error handling for get<N>()
@ 2023-04-21 10:11 Jan Beulich
0 siblings, 0 replies; only message in thread
From: Jan Beulich @ 2023-04-21 10:11 UTC (permalink / raw)
To: bfd-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=a82b3c5656d62a47173ddebab52819a2d0788de7
commit a82b3c5656d62a47173ddebab52819a2d0788de7
Author: Jan Beulich <jbeulich@suse.com>
Date: Fri Apr 21 12:09:35 2023 +0200
x86: change fetch error handling for get<N>()
Make them return boolean and convert FETCH_DATA() uses to fetch_code().
With this no further users of FETCH_DATA() remain, so the macro and its
backing function are dropped as well.
Leave value types as they were for the helper functions, even if I don't
think that beyond get64() use of bfd_{,signed_}vma is really necessary.
With type change of "disp" in OP_E_memory(), change the 2nd parameter of
print_displacement() to a signed type as well, though (eliminating the
need for a local variable of signed type). This also eliminates the need
for custom printing of '-' in Intel syntax displacement expressions.
While there drop forward declarations which aren't really needed.
Diff:
---
opcodes/i386-dis.c | 247 +++++++++++++++++++++++++----------------------------
1 file changed, 114 insertions(+), 133 deletions(-)
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index aeb10558ee1..24815389353 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -48,10 +48,8 @@ static void oappend_with_style (instr_info *, const char *,
enum disassembler_style);
static void oappend (instr_info *, const char *);
static void append_seg (instr_info *);
-static bfd_vma get64 (instr_info *);
-static bfd_signed_vma get32 (instr_info *);
-static bfd_signed_vma get32s (instr_info *);
-static int get16 (instr_info *);
+static bool get32s (instr_info *, bfd_signed_vma *);
+static bool get16 (instr_info *, int *);
static void set_op (instr_info *, bfd_vma, bool);
static bool OP_E (instr_info *, int, int);
@@ -295,41 +293,8 @@ struct instr_info
#define PREFIX_FWAIT 0x800
/* Make sure that bytes from INFO->PRIVATE_DATA->BUFFER (inclusive)
- to ADDR (exclusive) are valid. Returns 1 for success, longjmps
+ to ADDR (exclusive) are valid. Returns true for success, false
on error. */
-#define FETCH_DATA(info, addr) \
- ((addr) <= ((struct dis_private *) (info->private_data))->max_fetched \
- ? 1 : fetch_data ((info), (addr)))
-
-static int
-fetch_data (struct disassemble_info *info, bfd_byte *addr)
-{
- int status;
- struct dis_private *priv = (struct dis_private *) info->private_data;
- bfd_vma start = priv->insn_start + (priv->max_fetched - priv->the_buffer);
-
- if (addr <= priv->the_buffer + MAX_MNEM_SIZE)
- status = (*info->read_memory_func) (start,
- priv->max_fetched,
- addr - priv->max_fetched,
- info);
- else
- status = -1;
- if (status != 0)
- {
- /* If we did manage to read at least one byte, then
- print_insn_i386 will do something sensible. Otherwise, print
- an error. We do that here because this is where we know
- STATUS. */
- if (priv->max_fetched == priv->the_buffer)
- (*info->memory_error_func) (status, start, info);
- OPCODES_SIGLONGJMP (priv->bailout, 1);
- }
- else
- priv->max_fetched = addr;
- return 1;
-}
-
static bool
fetch_code (struct disassemble_info *info, bfd_byte *until)
{
@@ -11444,15 +11409,14 @@ oappend_immediate (instr_info *ins, bfd_vma imm)
/* Put DISP in BUF as signed hex number. */
static void
-print_displacement (instr_info *ins, bfd_vma disp)
+print_displacement (instr_info *ins, bfd_signed_vma val)
{
- bfd_signed_vma val = disp;
char tmp[30];
if (val < 0)
{
oappend_char_with_style (ins, '-', dis_style_address_offset);
- val = -disp;
+ val = (bfd_vma) 0 - val;
/* Check for possible overflow. */
if (val < 0)
@@ -11862,7 +11826,6 @@ print_register (instr_info *ins, unsigned int reg, unsigned int rexmask,
static bool
OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
{
- bfd_vma disp = 0;
int add = (ins->rex & REX_B) ? 8 : 0;
int riprel = 0;
int shift;
@@ -11971,6 +11934,7 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
if ((sizeflag & AFLAG) || ins->address_mode == mode_64bit)
{
/* 32/64 bit address mode */
+ bfd_signed_vma disp = 0;
int havedisp;
int havebase;
int needindex;
@@ -12062,7 +12026,8 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
havebase = 0;
if (ins->address_mode == mode_64bit && !ins->has_sib)
riprel = 1;
- disp = get32s (ins);
+ if (!get32s (ins, &disp))
+ return false;
if (riprel && bytemode == v_bndmk_mode)
{
oappend (ins, "(bad)");
@@ -12080,7 +12045,8 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
disp <<= shift;
break;
case 2:
- disp = get32s (ins);
+ if (!get32s (ins, &disp))
+ return false;
break;
}
@@ -12186,14 +12152,8 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
if (ins->intel_syntax
&& (disp || ins->modrm.mod != 0 || base == 5))
{
- if (!havedisp || (bfd_signed_vma) disp >= 0)
+ if (!havedisp || disp >= 0)
oappend_char (ins, '+');
- else if (ins->modrm.mod != 1 && disp != -disp)
- {
- oappend_char (ins, '-');
- disp = -disp;
- }
-
if (havedisp)
print_displacement (ins, disp);
else
@@ -12241,13 +12201,17 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
else
{
/* 16 bit address mode */
+ int disp = 0;
+
ins->used_prefixes |= ins->prefixes & PREFIX_ADDR;
switch (ins->modrm.mod)
{
case 0:
if (ins->modrm.rm == 6)
{
- disp = get16 (ins);
+ case 2:
+ if (!get16 (ins, &disp))
+ return false;
if ((disp & 0x8000) != 0)
disp -= 0x10000;
}
@@ -12261,11 +12225,6 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
if (ins->vex.evex && shift > 0)
disp <<= shift;
break;
- case 2:
- disp = get16 (ins);
- if ((disp & 0x8000) != 0)
- disp -= 0x10000;
- break;
}
if (!ins->intel_syntax)
@@ -12280,14 +12239,8 @@ OP_E_memory (instr_info *ins, int bytemode, int sizeflag)
if (ins->intel_syntax
&& (disp || ins->modrm.mod != 0 || ins->modrm.rm == 6))
{
- if ((bfd_signed_vma) disp >= 0)
+ if (disp >= 0)
oappend_char (ins, '+');
- else if (ins->modrm.mod != 1)
- {
- oappend_char (ins, '-');
- disp = -disp;
- }
-
print_displacement (ins, disp);
}
@@ -12414,14 +12367,14 @@ OP_G (instr_info *ins, int bytemode, int sizeflag)
}
#ifdef BFD64
-static bfd_vma
-get64 (instr_info *ins)
+static bool
+get64 (instr_info *ins, bfd_vma *res)
{
- bfd_vma x;
unsigned int a;
unsigned int b;
- FETCH_DATA (ins->info, ins->codep + 8);
+ if (!fetch_code (ins->info, ins->codep + 8))
+ return false;
a = *ins->codep++ & 0xff;
a |= (*ins->codep++ & 0xff) << 8;
a |= (*ins->codep++ & 0xff) << 16;
@@ -12430,56 +12383,49 @@ get64 (instr_info *ins)
b |= (*ins->codep++ & 0xff) << 8;
b |= (*ins->codep++ & 0xff) << 16;
b |= (*ins->codep++ & 0xffu) << 24;
- x = a + ((bfd_vma) b << 32);
- return x;
+ *res = a + ((bfd_vma) b << 32);
+ return true;
}
#else
-static bfd_vma
-get64 (instr_info *ins ATTRIBUTE_UNUSED)
+static bool
+get64 (instr_info *ins ATTRIBUTE_UNUSED, bfd_vma *res ATTRIBUTE_UNUSED)
{
abort ();
- return 0;
+ return false;
}
#endif
-static bfd_signed_vma
-get32 (instr_info *ins)
+static bool
+get32 (instr_info *ins, bfd_signed_vma *res)
{
- bfd_vma x = 0;
-
- FETCH_DATA (ins->info, ins->codep + 4);
- x = *ins->codep++ & (bfd_vma) 0xff;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 8;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 16;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 24;
- return x;
+ if (!fetch_code (ins->info, ins->codep + 4))
+ return false;
+ *res = *ins->codep++ & (bfd_vma) 0xff;
+ *res |= (*ins->codep++ & (bfd_vma) 0xff) << 8;
+ *res |= (*ins->codep++ & (bfd_vma) 0xff) << 16;
+ *res |= (*ins->codep++ & (bfd_vma) 0xff) << 24;
+ return true;
}
-static bfd_signed_vma
-get32s (instr_info *ins)
+static bool
+get32s (instr_info *ins, bfd_signed_vma *res)
{
- bfd_vma x = 0;
-
- FETCH_DATA (ins->info, ins->codep + 4);
- x = *ins->codep++ & (bfd_vma) 0xff;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 8;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 16;
- x |= (*ins->codep++ & (bfd_vma) 0xff) << 24;
+ if (!get32 (ins, res))
+ return false;
- x = (x ^ ((bfd_vma) 1 << 31)) - ((bfd_vma) 1 << 31);
+ *res = (*res ^ ((bfd_vma) 1 << 31)) - ((bfd_vma) 1 << 31);
- return x;
+ return true;
}
-static int
-get16 (instr_info *ins)
+static bool
+get16 (instr_info *ins, int *res)
{
- int x = 0;
-
- FETCH_DATA (ins->info, ins->codep + 2);
- x = *ins->codep++ & 0xff;
- x |= (*ins->codep++ & 0xff) << 8;
- return x;
+ if (!fetch_code (ins->info, ins->codep + 2))
+ return false;
+ *res = *ins->codep++ & 0xff;
+ *res |= (*ins->codep++ & 0xff) << 8;
+ return true;
}
static void
@@ -12619,30 +12565,32 @@ OP_I (instr_info *ins, int bytemode, int sizeflag)
case v_mode:
USED_REX (REX_W);
if (ins->rex & REX_W)
- op = get32s (ins);
+ {
+ if (!get32s (ins, &op))
+ return false;
+ }
else
{
+ ins->used_prefixes |= (ins->prefixes & PREFIX_DATA);
if (sizeflag & DFLAG)
{
- op = get32 (ins);
+ case d_mode:
+ if (!get32 (ins, &op))
+ return false;
mask = 0xffffffff;
}
else
{
- op = get16 (ins);
+ int num;
+
+ case w_mode:
+ if (!get16 (ins, &num))
+ return false;
+ op = num;
mask = 0xfffff;
}
- ins->used_prefixes |= (ins->prefixes & PREFIX_DATA);
}
break;
- case d_mode:
- mask = 0xffffffff;
- op = get32 (ins);
- break;
- case w_mode:
- mask = 0xfffff;
- op = get16 (ins);
- break;
case const_1_mode:
if (ins->intel_syntax)
oappend (ins, "1");
@@ -12660,13 +12608,18 @@ OP_I (instr_info *ins, int bytemode, int sizeflag)
static bool
OP_I64 (instr_info *ins, int bytemode, int sizeflag)
{
+ bfd_vma op;
+
if (bytemode != v_mode || ins->address_mode != mode_64bit
|| !(ins->rex & REX_W))
return OP_I (ins, bytemode, sizeflag);
USED_REX (REX_W);
- oappend_immediate (ins, get64 (ins));
+ if (!get64 (ins, &op))
+ return false;
+
+ oappend_immediate (ins, op);
return true;
}
@@ -12709,10 +12662,16 @@ OP_sI (instr_info *ins, int bytemode, int sizeflag)
break;
case v_mode:
/* The operand-size prefix is overridden by a REX prefix. */
- if ((sizeflag & DFLAG) || (ins->rex & REX_W))
- op = get32s (ins);
- else
- op = get16 (ins);
+ if (!(sizeflag & DFLAG) && !(ins->rex & REX_W))
+ {
+ int val;
+
+ if (!get16 (ins, &val))
+ return false;
+ op = val;
+ }
+ else if (!get32s (ins, &op))
+ return false;
break;
default:
oappend (ins, INTERNAL_DISASSEMBLER_ERROR);
@@ -12745,12 +12704,19 @@ OP_J (instr_info *ins, int bytemode, int sizeflag)
|| (ins->address_mode == mode_64bit
&& ((ins->isa64 == intel64 && bytemode != dqw_mode)
|| (ins->rex & REX_W))))
- disp = get32s (ins);
+ {
+ bfd_signed_vma val;
+
+ if (!get32s (ins, &val))
+ return false;
+ disp = val;
+ }
else
{
- disp = get16 (ins);
- if ((disp & 0x8000) != 0)
- disp -= 0x10000;
+ int val;
+
+ get16 (ins, &val);
+ disp = val & 0x8000 ? val - 0x10000 : val;
/* In 16bit mode, address is wrapped around at 64k within
the same segment. Otherwise, a data16 prefix on a jump
instruction means that the pc is masked to 16 bits after
@@ -12794,14 +12760,16 @@ OP_DIR (instr_info *ins, int dummy ATTRIBUTE_UNUSED, int sizeflag)
if (sizeflag & DFLAG)
{
- offset = get32 (ins);
- seg = get16 (ins);
- }
- else
- {
- offset = get16 (ins);
- seg = get16 (ins);
+ bfd_signed_vma val;
+
+ if (!get32 (ins, &val))
+ return false;;
+ offset = val;
}
+ else if (!get16 (ins, &offset))
+ return false;
+ if (!get16 (ins, &seg))
+ return false;;
ins->used_prefixes |= (ins->prefixes & PREFIX_DATA);
res = snprintf (scratch, ARRAY_SIZE (scratch),
@@ -12823,9 +12791,21 @@ OP_OFF (instr_info *ins, int bytemode, int sizeflag)
append_seg (ins);
if ((sizeflag & AFLAG) || ins->address_mode == mode_64bit)
- off = get32 (ins);
+ {
+ bfd_signed_vma val;
+
+ if (!get32 (ins, &val))
+ return false;
+ off = val;
+ }
else
- off = get16 (ins);
+ {
+ int val;
+
+ if (!get16 (ins, &val))
+ return false;
+ off = val;
+ }
if (ins->intel_syntax)
{
@@ -12852,7 +12832,8 @@ OP_OFF64 (instr_info *ins, int bytemode, int sizeflag)
intel_operand_size (ins, bytemode, sizeflag);
append_seg (ins);
- off = get64 (ins);
+ if (!get64 (ins, &off))
+ return false;
if (ins->intel_syntax)
{
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2023-04-21 10:11 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-04-21 10:11 [binutils-gdb] x86: change fetch error handling for get<N>() Jan Beulich
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).