glibc -fstack-protector-strong


Paul Eggleton
 

Hi folks

I'm looking at how -fstack-protector-strong might be enabled in the glibc
recipe. It looks like it should already be enabled by default via
--enable-stack-protector=strong in EXTRA_OECONF, however looking at the
compile logs it is passing -fno-stack-protector instead. Examining the
configure log:

checking for -fstack-protector... (cached) no
checking for -fstack-protector-strong... (cached) no
checking for -fstack-protector-all... (cached) no

This in turn comes from libc_cv_ssp_strong=no in CACHED_CONFIGUREVARS in
glibc.inc. Searching back through the git history I can't find much by way of
explanation as to why the stack protector options are disabled. Setting
libc_cv_ssp_strong=yes however results in the following:

| x86_64-poky-linux-gcc -m64 -march=core2 -mtune=core2 -msse3 -mfpmath=sse --sysroot=/media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/recipe-sysroot -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -Wl,-z,relro,-z,now -fuse-ld=bfd -nostdlib -nostartfiles -r -o /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.os \
| -Wl,-d -Wl,--whole-archive /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.a -o /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.os
| x86_64-poky-linux-gcc -m64 -march=core2 -mtune=core2 -msse3 -mfpmath=sse --sysroot=/media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/recipe-sysroot -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -Wl,-z,relro,-z,now -fuse-ld=bfd -nostdlib -nostartfiles -r -o /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/librtld.map.o \
| '-Wl,-(' /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/dl-allobjs.os /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.a -lgcc '-Wl,-)' -Wl,-Map,/media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/librtld.mapT
| /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/recipe-sysroot-native/usr/bin/x86_64-poky-linux/../../libexec/x86_64-poky-linux/gcc/x86_64-poky-linux/9.3.0/ld.bfd: /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.a(libc_fatal.os): in function `__GI___libc_fatal':
| /usr/src/debug/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git/libio/../sysdeps/posix/libc_fatal.c:161: multiple definition of `__GI___libc_fatal'; /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/dl-allobjs.os:/usr/src/debug/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git/elf/dl-minimal.c:188: first defined here
| /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/recipe-sysroot-native/usr/bin/x86_64-poky-linux/../../libexec/x86_64-poky-linux/gcc/x86_64-poky-linux/9.3.0/ld.bfd: /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/libc_pic.a(libc_fatal.os): in function `__GI___libc_fatal':
| /usr/src/debug/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git/libio/../sysdeps/posix/libc_fatal.c:161: multiple definition of `__libc_fatal'; /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/dl-allobjs.os:/usr/src/debug/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git/elf/dl-minimal.c:188: first defined here
| collect2: error: ld returned 1 exit status
| make[2]: *** [Makefile:499: /media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/build-x86_64-poky-linux/elf/librtld.map] Error 1
| make[2]: *** Waiting for unfinished jobs....
| make[2]: Leaving directory '/media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git/elf'
| make[1]: *** [Makefile:490: elf/subdir_lib] Error 2
| make[1]: Leaving directory '/media/large/oe/poky/tmp/work/core2-64-poky-linux/glibc/2.31+gitAUTOINC+4f0a61f753-r0/git'
| make: *** [Makefile:9: all] Error 2
| ERROR: oe_runmake failed

This is not an area I have looked much into before; does anyone have any insights?

Thanks
Paul

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