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author | Richard Henderson <rth@redhat.com> | 2013-05-17 08:27:37 -0700 |
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committer | Richard Henderson <rth@gcc.gnu.org> | 2013-05-17 08:27:37 -0700 |
commit | 0ec3322408800c96e750e9ee28f64dfbb259cfb3 (patch) | |
tree | 545aebc5456658d87774829e39cd3651a5e27df8 /libgcc/unwind-dw2.c | |
parent | 38c821cf31574eb73cf27eec4573fd7e51217fcb (diff) | |
download | gcc-0ec3322408800c96e750e9ee28f64dfbb259cfb3.zip gcc-0ec3322408800c96e750e9ee28f64dfbb259cfb3.tar.gz gcc-0ec3322408800c96e750e9ee28f64dfbb259cfb3.tar.bz2 |
re PR target/49146 (segv from libgcc_s when raising an exception, or unwinding stack with backtrace with ms_abi)
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
Diffstat (limited to 'libgcc/unwind-dw2.c')
-rw-r--r-- | libgcc/unwind-dw2.c | 125 |
1 files changed, 95 insertions, 30 deletions
diff --git a/libgcc/unwind-dw2.c b/libgcc/unwind-dw2.c index 80de5ab..041f9d5 100644 --- a/libgcc/unwind-dw2.c +++ b/libgcc/unwind-dw2.c @@ -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, ®); 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, ®); /* 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, ®); - 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, ®); - 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, ®); insn_ptr = read_uleb128 (insn_ptr, ®2); - 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, ®); - 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, ®); 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, ®); 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, ®); 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, ®); - 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, ®); 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: |