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| author | Vineet Gupta <vgupta@synopsys.com> | 2016-09-16 11:14:36 -0700 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2016-09-30 14:48:21 -0700 |
| commit | 2d0486424791b0d012d060854ce3bd1c6217a82c (patch) | |
| tree | 8b6be81f4d4deba89125e046bd2af265b3b4e503 /arch/arc | |
| parent | 6716dbbdefa9867ba98dea91d89b14168043a48c (diff) | |
| download | linux-2d0486424791b0d012d060854ce3bd1c6217a82c.tar.bz2 | |
ARC: dw2 unwind: don't force dwarf 2
In .debug_frame based unwinding regime, we used to force -gdwarf-2 since
kernel unwinder only claimed to handle dwarf 2. This changed since commit
6d0d506012c93d ("ARC: dw2 unwind: Don't bail for CIE.version != 1")
which added some support beyond dwarf 2, atleast to handle CIE != 1
The ill-effect of -gdwarf-2 is that it forces generation of .debug_*
sections, which bloats loadable modules .ko files. For the curious, this
doesn't affect vmlinx binary since linker script discards .debug_* but
same discard is not yet implemented for modules.
So it seems we can drop the -gdwarf-2 toggle, which should not be needed
anyways given that we now use .eh_frame based unwinding.
I've verified using GNU 2016.09-engo10 that the actual unwind info is
not different with or w/o this toggle - but the debug_* sections are
gone for good.
before
-----
arc-linux-readelf -S q_proc.ko-unwinding-1-eh_frame-switch | grep debug
[15] .debug_info PROGBITS 00000000 000300 00d08d 00 0 0 1
[16] .rela.debug_info RELA 00000000 0162a0 008844 0c I 29 15 4
[17] .debug_abbrev PROGBITS 00000000 00d38d 0005f8 00 0 0 1
[18] .debug_loc PROGBITS 00000000 00d985 000070 00 0 0 1
[19] .rela.debug_loc RELA 00000000 01eae4 0000c0 0c I 29 18 4
[20] .debug_aranges PROGBITS 00000000 00d9f5 000040 00 0 0 1
[21] .rela.debug_arang RELA 00000000 01eba4 000030 0c I 29 20 4
[22] .debug_ranges PROGBITS 00000000 00da35 000018 00 0 0 1
[23] .rela.debug_range RELA 00000000 01ebd4 000030 0c I 29 22 4
[24] .debug_line PROGBITS 00000000 00da4d 000b5b 00 0 0 1
[25] .rela.debug_line RELA 00000000 01ec04 0000cc 0c I 29 24 4
[26] .debug_str PROGBITS 00000000 00e5a8 007831 01 MS 0 0 1
after
----
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
| -rw-r--r-- | arch/arc/Makefile | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/arch/arc/Makefile b/arch/arc/Makefile index fc6ff8f09f23..a2a6a4614241 100644 --- a/arch/arc/Makefile +++ b/arch/arc/Makefile @@ -47,7 +47,6 @@ endif upto_gcc44 := $(call cc-ifversion, -le, 0404, y) atleast_gcc44 := $(call cc-ifversion, -ge, 0404, y) -atleast_gcc48 := $(call cc-ifversion, -ge, 0408, y) cflags-$(atleast_gcc44) += -fsection-anchors @@ -68,11 +67,6 @@ endif cflags-$(CONFIG_ARC_DW2_UNWIND) += -fasynchronous-unwind-tables -# By default gcc 4.8 generates dwarf4 which kernel unwinder can't grok -ifeq ($(atleast_gcc48),y) -cflags-$(CONFIG_ARC_DW2_UNWIND) += -gdwarf-2 -endif - ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE # Generic build system uses -O2, we want -O3 # Note: No need to add to cflags-y as that happens anyways |