Messages in this thread | | | Date | Wed, 11 Feb 2009 11:57:29 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCHSET x86/master] add stack protector support for x86_32 |
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* Tejun Heo <tj@kernel.org> wrote:
> Ingo Molnar wrote: > >>> I'll try other compilers but which version are you using? The > >>> difference is that before the patchset, -fno-stack-protector was > >>> always added whether stackprotector was enabled or not so this problem > >>> wasn't visible (at the cost of bogus stackprotector of course). We'll > >>> probably need to add __stack_chk_guard or disable if gcc generates > >>> such symbol. I'll play with different gccs. > >> Can't reproduce with gcc-4.1 or 4.2. Any chance you're using distcc > >> w/ a build machine w/ glibc < 2.4? __stack_chk_guard is the symbol > >> gcc fetches stack canary from if TLS is not supported, so somehow gcc > >> thought that TLS wasn't available while building head64. > > > > yeah - i also used distcc. Maybe the nostackp makefile magic gets confused > > about that? > > It seems that even with the same gcc versions, gcc built against libc > w/o TLS support generates __stack_chk_guard, so if you mix the two > flavors, the has-stack-protector check can be compiled on machines w/ > TLS while some other files end up being built on machines w/o TLS > support thus circumventing the support check. Can you please see > whether non-distcc build fails too?
That build succeeds:
rhea:~/tip> make -j30 bzImage ARCH=x86_64 CROSS_COMPILE='/opt/crosstool/gcc-4.2.3-glibc-2.3.6/x86_64-unknown-linux-gnu/bin/x86_64-unknown-linux-gnu-' /home/mingo/tip/arch/x86/Makefile:82: stack protector enabled but no compiler support CHK include/linux/version.h [...] BFD: arch/x86/boot/compressed/vmlinux.bin: warning: allocated section `.bss' not in segment [...] Root device is (8, 3) Setup is 11996 bytes (padded to 12288 bytes). System is 5690 kB CRC be1b2e21 Kernel: arch/x86/boot/bzImage is ready (#3)
Some shell variable expansion bug? If CROSS_COMPILE is not a single word we fail to detect the compiler borkage at arch/x86/Makefile line 82?
Ingo
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