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re PR target/49146 (segv from libgcc_s when raising an exception, or unwinding stack with backtrace with ms_abi)

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PR target/49146

	* unwind-dw2.c (UNWIND_COLUMN_IN_RANGE): New macro.
	(execute_cfa_program): Use it when storing to fs->regs.

From-SVN: r199019
This commit is contained in:
Richard Henderson 2013-05-17 08:27:37 -07:00 • committed by Richard Henderson
parent 38c821cf31
commit 0ec3322408
2 changed files with 101 additions and 30 deletions
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6
libgcc/ChangeLog
View file

@ -1,3 +1,9 @@
2013-05-17 Richard Henderson <rth@redhat.com>
PR target/49146
* unwind-dw2.c (UNWIND_COLUMN_IN_RANGE): New macro.
(execute_cfa_program): Use it when storing to fs->regs.
2013-05-08 Kai Tietz <ktietz@redhat.com>
* config/i386/cygming-crtbegin.c (__register_frame_info): Make weak.

125
libgcc/unwind-dw2.c
View file

@ -59,6 +59,35 @@
#define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO)
#endif
/* ??? For the public function interfaces, we tend to gcc_assert that the
column numbers are in range. For the dwarf2 unwind info this does happen,
although so far in a case that doesn't actually matter.
See PR49146, in which a call from x86_64 ms abi to x86_64 unix abi stores
the call-saved xmm registers and annotates them. We havn't bothered
providing support for the xmm registers for the x86_64 port primarily
because the 64-bit windows targets don't use dwarf2 unwind, using sjlj or
SEH instead. Adding the support for unix targets would generally be a
waste. However, some runtime libraries supplied with ICC do contain such
an unorthodox transition, as well as the unwind info to match. This loss
of register restoration doesn't matter in practice, because the exception
is caught in the native unix abi, where all of the xmm registers are
call clobbered.
Ideally, we'd record some bit to notice when we're failing to restore some
register recorded in the unwind info, but to do that we need annotation on
the unix->ms abi edge, so that we know when the register data may be
discarded. And since this edge is also within the ICC library, we're
unlikely to be able to get the new annotation.
Barring a magic solution to restore the ms abi defined 128-bit xmm registers
(as distictly opposed to the full runtime width) without causing extra
overhead for normal unix abis, the best solution seems to be to simply
ignore unwind data for unknown columns. */
#define UNWIND_COLUMN_IN_RANGE(x) \
__builtin_expect((x) <= DWARF_FRAME_REGISTERS, 1)
#ifdef REG_VALUE_IN_UNWIND_CONTEXT
typedef _Unwind_Word _Unwind_Context_Reg_Val;
@ -939,14 +968,19 @@ execute_cfa_program (const unsigned char *insn_ptr,
reg = insn & 0x3f;
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Sword) utmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
}
else if ((insn & 0xc0) == DW_CFA_restore)
{
reg = insn & 0x3f;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_UNSAVED;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
fs->regs.reg[reg].how = REG_UNSAVED;
}
else switch (insn)
{
@ -977,26 +1011,35 @@ execute_cfa_program (const unsigned char *insn_ptr,
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Sword) utmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
break;
case DW_CFA_restore_extended:
insn_ptr = read_uleb128 (insn_ptr, &reg);
/* FIXME, this is wrong; the CIE might have said that the
register was saved somewhere. */
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
fs->regs.reg[reg].how = REG_UNSAVED;
break;
case DW_CFA_same_value:
insn_ptr = read_uleb128 (insn_ptr, &reg);
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
fs->regs.reg[reg].how = REG_UNSAVED;
break;
case DW_CFA_undefined:
insn_ptr = read_uleb128 (insn_ptr, &reg);
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNDEFINED;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
fs->regs.reg[reg].how = REG_UNDEFINED;
break;
case DW_CFA_nop:
@ -1007,9 +1050,12 @@ execute_cfa_program (const unsigned char *insn_ptr,
_uleb128_t reg2;
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_uleb128 (insn_ptr, &reg2);
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_REG;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.reg =
(_Unwind_Word)reg2;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_REG;
fs->regs.reg[reg].loc.reg = (_Unwind_Word)reg2;
}
}
break;
@ -1067,8 +1113,12 @@ execute_cfa_program (const unsigned char *insn_ptr,
case DW_CFA_expression:
insn_ptr = read_uleb128 (insn_ptr, &reg);
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_EXP;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.exp = insn_ptr;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_EXP;
fs->regs.reg[reg].loc.exp = insn_ptr;
}
insn_ptr = read_uleb128 (insn_ptr, &utmp);
insn_ptr += utmp;
break;
@ -1078,9 +1128,12 @@ execute_cfa_program (const unsigned char *insn_ptr,
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_sleb128 (insn_ptr, &stmp);
offset = stmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
break;
case DW_CFA_def_cfa_sf:
@ -1103,25 +1156,34 @@ execute_cfa_program (const unsigned char *insn_ptr,
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Sword) utmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_VAL_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
break;
case DW_CFA_val_offset_sf:
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_sleb128 (insn_ptr, &stmp);
offset = stmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_VAL_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
break;
case DW_CFA_val_expression:
insn_ptr = read_uleb128 (insn_ptr, &reg);
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_VAL_EXP;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.exp = insn_ptr;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_VAL_EXP;
fs->regs.reg[reg].loc.exp = insn_ptr;
}
insn_ptr = read_uleb128 (insn_ptr, &utmp);
insn_ptr += utmp;
break;
@ -1147,9 +1209,12 @@ execute_cfa_program (const unsigned char *insn_ptr,
insn_ptr = read_uleb128 (insn_ptr, &reg);
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Word) utmp * fs->data_align;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
= REG_SAVED_OFFSET;
fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = -offset;
reg = DWARF_REG_TO_UNWIND_COLUMN (reg);
if (UNWIND_COLUMN_IN_RANGE (reg))
{
fs->regs.reg[reg].how = REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = -offset;
}
break;
default: