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| author |   Matt Fleming <matt@console-pimps.org> | 2009-08-16 01:44:33 +0100 |
|---|---|---|
| committer | Matt Fleming <matt@console-pimps.org> | 2009-08-16 12:48:53 +0100 |
| commit | cd7246f0e2747bd2b43d25d0f63f05db182a62c0 (patch) | |
| tree | 729c855c6e17a35b8467161baeeb6431765cf372 /arch/sh | |
| parent | sh: Try again at getting the initial return address for an unwind (diff) | |
| download | linux-dev-cd7246f0e2747bd2b43d25d0f63f05db182a62c0.tar.xz linux-dev-cd7246f0e2747bd2b43d25d0f63f05db182a62c0.zip | |
sh: Add support for DWARF GNU extensions
Also, remove the "fix" to DW_CFA_def_cfa_register where we reset the
frame's cfa_offset to 0. This action is incorrect when handling
DW_CFA_def_cfa_register as the DWARF spec specifically states that the
previous contents of cfa_offset should be used with the new
register. The reason that I thought cfa_offset should be reset to 0 was
because it was being assigned a bogus value prior to executing the
DW_CFA_def_cfa_register op. It turns out that the bogus cfa_offset value
came from interpreting .cfi_escape pseudo-ops (those used by the GNU
extensions) as CFA_DW_def_cfa ops.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Diffstat (limited to 'arch/sh')
| -rw-r--r-- | arch/sh/include/asm/dwarf.h | 4 | ||||
| -rw-r--r-- | arch/sh/kernel/dwarf.c | 14 |
2 files changed, 17 insertions, 1 deletions
diff --git a/arch/sh/include/asm/dwarf.h b/arch/sh/include/asm/dwarf.h index 60b180728d8d..d3d3837c5e1b 100644 --- a/arch/sh/include/asm/dwarf.h +++ b/arch/sh/include/asm/dwarf.h @@ -340,6 +340,10 @@ struct dwarf_stack { #define DW_CFA_lo_user 0x1c #define DW_CFA_hi_user 0x3f +/* GNU extension opcodes */ +#define DW_CFA_GNU_args_size 0x2e +#define DW_CFA_GNU_negative_offset_extended 0x2f + /* * Some call frame instructions encode their operands in the opcode. We * need some helper functions to extract both the opcode and operands diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c index 44e674ed2871..5fd6e604816d 100644 --- a/arch/sh/kernel/dwarf.c +++ b/arch/sh/kernel/dwarf.c @@ -429,7 +429,6 @@ static int dwarf_cfa_execute_insns(unsigned char *insn_start, count = dwarf_read_uleb128(current_insn, &frame->cfa_register); current_insn += count; - frame->cfa_offset = 0; frame->flags |= DWARF_FRAME_CFA_REG_OFFSET; break; case DW_CFA_def_cfa_offset: @@ -465,6 +464,19 @@ static int dwarf_cfa_execute_insns(unsigned char *insn_start, frame->regs[reg].flags |= DWARF_REG_OFFSET; frame->regs[reg].addr = offset; break; + case DW_CFA_GNU_args_size: + count = dwarf_read_uleb128(current_insn, &offset); + current_insn += count; + break; + case DW_CFA_GNU_negative_offset_extended: + count = dwarf_read_uleb128(current_insn, ®); + current_insn += count; + count = dwarf_read_uleb128(current_insn, &offset); + offset *= cie->data_alignment_factor; + dwarf_frame_alloc_regs(frame, reg); + frame->regs[reg].flags |= DWARF_REG_OFFSET; + frame->regs[reg].addr = -offset; + break; default: pr_debug("unhandled DWARF instruction 0x%x\n", insn); break; |