Request 4314 (accepted)

Overview

Request 4314 (accepted)

fix crashes on init (add remove-.rotext.patch)

Created by jirislaby about 6 years ago
In state accepted
Package maintainers: detrei and mantre

Submit xvid

Submit package home:jirislaby:branches:Essentials / xvid to package Essentials / xvid

xvidcore.changes Changed

xvidcore.spec Changed

remove-.rotext.patch Added

@@ -0,0 +1,58 @@
+From: Jiri Slaby <jslaby@suse.cz>
+Subject: remove .rotext section
+Patch-mainline: haven't tried to submit
+
+avidemux and others crash right when the initialization routine of xvid
+(xvid_global) is called:
+> #0  0x00007fffde18d920 in check_cpu_features () from /usr/lib64/libxvidcore.so.4
+> #1  0x00007fffde1070db in detect_cpu_flags () at ../../src/xvid.c:156
+> #2  0x00007fffde1081e5 in xvid_gbl_init (init=0x7fffffffd304, init=0x7fffffffd304) at ../../src/xvid.c:793
+> #3  xvid_global (handle=<optimized out>, opt=<optimized out>, param1=0x7fffffffd304, param2=<optimized out>) at ../../src/xvid.c:816
+...
+
+It is because xvid tries to call a function written in assembly and the
+authors decided to put it in a section called .rotext. The same as other
+assembly functions:
+ 15 .rotext       00022f69  0000000000075140  0000000000075140  00075140  2**5
+                  CONTENTS, ALLOC, LOAD, READONLY, DATA
+
+As can be seen, it is marked as DATA and not CODE, so it ends up in data
+program headers without permissions to execute it:
+  LOAD           0x000000000006a000 0x000000000006a000 0x000000000006a000
+                 0x0000000000035070 0x0000000000035070  R      0x1000
+
+...
+ Section to Segment mapping:
+  Segment Sections...
+   02     .rodata .rotext .eh_frame_hdr .eh_frame 
+
+So kill .rotext which is no "standard" section and use .text as usual.
+Note that .text *is* read-only in any way:
+  LOAD           0x0000000000002000 0x0000000000002000 0x0000000000002000
+                 0x000000000008a1d5 0x000000000008a1d5  R E    0x1000
+
+This could work in the past versions of binutils/nasm, but not with my:
+binutils-2.31
+nasm-2.13.03
+---
+ src/nasm.inc |    8 --------
+ 1 file changed, 8 deletions(-)
+
+--- a/src/nasm.inc
++++ b/src/nasm.inc
+@@ -175,15 +175,7 @@ BITS 32
+ %endmacro
+ 
+ %macro TEXT 0
+-%ifidn __OUTPUT_FORMAT__,macho32
+       SECTION .text align=SECTION_ALIGN
+-%else
+-%ifidn __OUTPUT_FORMAT__,macho64
+-      SECTION .text align=SECTION_ALIGN
+-%else
+-      SECTION .rotext align=SECTION_ALIGN
+-%endif
+-%endif
+ %endmacro
+ 
+ %macro cglobal 1

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Request History

jirislaby created request about 6 years ago

fix crashes on init (add remove-.rotext.patch)

olh accepted request about 6 years ago