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hppa: avoid TEXTREL in .eh_frame section (#447)

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Before the change hand-crafted .eh_frame section contained
ABS relocation and caused TEXTREL tag to be emitted:

```
$ ./configure --host=hppa2.0-unknown-linux-gnu LDFLAGS=-Wl,-z,text
$ make
...
/usr/libexec/gcc/hppa2.0-unknown-linux-gnu/ld:
    read-only segment has dynamic relocations.
```

Link failure is caused by absolute address of FDEs
encoded into .eh_frame entries.

Fixed TEXTREL by using pcrel (instead of ABS) encoding
for absolute addresses (__PIC__ code) by adding augmentation
information ("zR" CIE type).

All tests still pass on hppa2.0. The specific tests that still pass
and exercise this code path:
    testsuite/libffi.call/unwindtest.cc
    testsuite/libffi.call/unwindtest_ffi_call.cc

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
This commit is contained in:
Sergei Trofimovich
2019-04-27 15:53:28 -04:00
committed by Anthony Green
parent 06bf1a9dea
commit fadf1eb530
1 changed files with 23 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/pa/linux.S
+23 -2
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@@ -297,10 +297,18 @@ ffi_closure_pa32:
.LSCIE1:
.word 0x0 ;# CIE Identifier Tag
.byte 0x1 ;# CIE Version
#ifdef __PIC__
.ascii "zR\0" ;# CIE Augmentation: 'z' - data, 'R' - DW_EH_PE_... data
#else
.ascii "\0" ;# CIE Augmentation
#endif
.uleb128 0x1 ;# CIE Code Alignment Factor
.sleb128 4 ;# CIE Data Alignment Factor
.byte 0x2 ;# CIE RA Column
#ifdef __PIC__
.uleb128 0x1 ;# Augmentation size
.byte 0x1b ;# FDE Encoding (DW_EH_PE_pcrel|DW_EH_PE_sdata4)
#endif
.byte 0xc ;# DW_CFA_def_cfa
.uleb128 0x1e
.uleb128 0x0
@@ -310,9 +318,15 @@ ffi_closure_pa32:
.word .LEFDE1-.LASFDE1 ;# FDE Length
.LASFDE1:
.word .LASFDE1-.Lframe1 ;# FDE CIE offset
.word .LFB1 ;# FDE initial location
#ifdef __PIC__
.word .LFB1-. ;# FDE initial location
#else
.word .LFB1 ;# FDE initial location
#endif
.word .LFE1-.LFB1 ;# FDE address range
#ifdef __PIC__
.uleb128 0x0 ;# Augmentation size: no data
#endif
.byte 0x4 ;# DW_CFA_advance_loc4
.word .LCFI11-.LFB1
.byte 0x83 ;# DW_CFA_offset, column 0x3
@@ -338,8 +352,15 @@ ffi_closure_pa32:
.word .LEFDE2-.LASFDE2 ;# FDE Length
.LASFDE2:
.word .LASFDE2-.Lframe1 ;# FDE CIE offset
#ifdef __PIC__
.word .LFB2-. ;# FDE initial location
#else
.word .LFB2 ;# FDE initial location
#endif
.word .LFE2-.LFB2 ;# FDE address range
#ifdef __PIC__
.uleb128 0x0 ;# Augmentation size: no data
#endif
.byte 0x4 ;# DW_CFA_advance_loc4
.word .LCFI21-.LFB2
.byte 0x83 ;# DW_CFA_offset, column 0x3