Date: Mon, 24 Sep 2018 21:36:38 +0200 From: Andreas Tobler <andreast@FreeBSD.org> To: Brooks Davis <brooks@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r338486 - in head/libexec/rtld-elf: . aarch64 arm mips powerpc powerpc64 riscv Message-ID: <7c8b106f-0b3c-f54c-3823-cadb0bb7a3ba@FreeBSD.org> In-Reply-To: <2ecbc67d-cf5c-8b8f-fcb3-08c6148ee297@FreeBSD.org> References: <201809052323.w85NNGMZ044128@repo.freebsd.org> <2ecbc67d-cf5c-8b8f-fcb3-08c6148ee297@FreeBSD.org>
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On 23.09.18 22:41, Andreas Tobler wrote: > Hi Brooks, > > On 06.09.18 01:23, Brooks Davis wrote: >> Author: brooks >> Date: Wed Sep 5 23:23:16 2018 >> New Revision: 338486 >> URL: https://svnweb.freebsd.org/changeset/base/338486 >> >> Log: >> Rework rtld's TLS Variant I implementation to match r326794 >> >> The above commit fixed handling overaligned TLS segments in libc's >> TLS Variant I implementation, but rtld provides its own implementation >> for dynamically-linked executables which lacks these fixes. Thus, >> port these changes to rtld. >> >> This was previously commited as r337978 and reverted in r338149 due to >> exposing a bug the ARM rtld. This bug was fixed in r338317 by mmel. >> >> Submitted by: James Clarke >> Approved by: re (kib) >> Reviewed by: kbowling >> Testing by: kbowling (powerpc64), br (riscv), kevans (armv7) > > And no testing on powerpc? > > This patch breaks ppc-32. It makes the system unusable, one can not even > login. Neither on the console nor via ssh. After entering the user I get > flooded with backslashes and the login shell dumps core. (Only visible > if I netboot) > > I'm testing now a fix and see if it survives world and kernel build. > >> Modified: head/libexec/rtld-elf/powerpc/rtld_machdep.h >> ============================================================================== >> --- head/libexec/rtld-elf/powerpc/rtld_machdep.h Wed Sep 5 21:47:22 2018 (r338485) >> +++ head/libexec/rtld-elf/powerpc/rtld_machdep.h Wed Sep 5 23:23:16 2018 (r338486) >> @@ -74,10 +74,11 @@ void _rtld_powerpc_pltcall(void); >> #define round(size, align) \ >> (((size) + (align) - 1) & ~((align) - 1)) >> #define calculate_first_tls_offset(size, align) \ >> - round(8, align) >> + TLS_TCB_SIZE > > Here, if I revert to 'round(8, align)', I can login again. But the fix > I'm testing now, is to increase the TLS_TCB_SIZE to 16 as suggested by > Justin. > > I'll let you know how it goes. So, here the feedback. Additional testing showed that increasing the TLS_TCB_SIZE is not enough. I have the below snippet which lets me build world/kernel and do some portmaster updates. If I use TLS_TCB_SIZE in calculate_first_tls_offset I get a system where I can login, but when I try to run 'portmaster' with arguments I get 'operator expected' on a option which works on other archs. Putting in round(8, align) instead of TLS_TCB_SIZE makes portmaster work again. And if I leave TLS_TCB_SIZE with 8, and only bring back round(8, align) is also not sufficient. I rebuild a few things again and then I propose the below for -CURRENT to re@. Unless someone else has a better idea. Regards, Andreas Index: libexec/rtld-elf/powerpc/rtld_machdep.h =================================================================== --- libexec/rtld-elf/powerpc/rtld_machdep.h (revision 338919) +++ libexec/rtld-elf/powerpc/rtld_machdep.h (working copy) @@ -69,12 +69,12 @@ #define TLS_TP_OFFSET 0x7000 #define TLS_DTV_OFFSET 0x8000 -#define TLS_TCB_SIZE 8 +#define TLS_TCB_SIZE 16 #define round(size, align) \ (((size) + (align) - 1) & ~((align) - 1)) #define calculate_first_tls_offset(size, align) \ - TLS_TCB_SIZE + round(8, align) #define calculate_tls_offset(prev_offset, prev_size, size, align) \ round(prev_offset + prev_size, align) #define calculate_tls_end(off, size) ((off) + (size))
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