From 95878586ec7611791f4001a4ee17abf943fae3c1 Mon Sep 17 00:00:00 2001 From: "https://me.yahoo.com/a/g3Ccalpj0NhN566pHbUl6i9QF0QEkrhlfPM-#b1c14" Date: Mon, 16 Feb 2015 20:08:03 +0100 Subject: rename open_issues.mdwn to service_solahart_jakarta_selatan__082122541663.mdwn --- .../glibc/t/tls.mdwn | 81 ++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 service_solahart_jakarta_selatan__082122541663/glibc/t/tls.mdwn (limited to 'service_solahart_jakarta_selatan__082122541663/glibc/t/tls.mdwn') diff --git a/service_solahart_jakarta_selatan__082122541663/glibc/t/tls.mdwn b/service_solahart_jakarta_selatan__082122541663/glibc/t/tls.mdwn new file mode 100644 index 00000000..b10703fd --- /dev/null +++ b/service_solahart_jakarta_selatan__082122541663/glibc/t/tls.mdwn @@ -0,0 +1,81 @@ +[[!meta copyright="Copyright © 2011, 2012, 2013 Free Software Foundation, +Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +[[!tag open_issue_glibc open_issue_libpthread]] + +# To Do + + * Discuss d2431f633e6139a62e1575ec18830f7e81160cf0 with Samuel. + + * Validate our implementation against + . + + +# Documentation + +[[!taglink open_issue_documentation]] + + * IRC, freenode, #hurd, 2011-11-26 + + In glibc multiarch support (strcasecmp for i686 SSE3, etc.) + there is access to memory via gs: -- this will need to be changed for + us, right? + depends on the access + * `optimized strcasecmp and strncasecmp for x86-32` + (multiarch), + 76e3966e9efc3808a9e7ad09121c5dfc1211c20b + + 6abf346582ba678f4850a88b4a5950593841df1d + + 5583a0862cf94f71cbcde91c4043a20af65facca. `gs` + access. + + movl __libc_tsd_LOCALE@GOTNTPOFF(%ebx), %eax + that's handled by the linker fine + it's only the things held in the tcb_t structure which can pose + problem + tcbhead_t? + I'm looking at this. + So, at gs:0, there is the TCB. + And we have the same layout as NPTL/Linux, just that we + don't have as much data there as they have. + We're missing multiple_threads, sysinfo, sttack_guard, + pointer_guard, gscope_flag, private_futex, __private_tm[5]. + So, if one of these is referenced (be it my name or by + numeric offset), this is invalid for us. + Anything else should work equivalently. + yes + usually the only numeric offset being used is 0 + so it would simply not build + And the other offsers are generated via tcb-offsets.sym. + glibc's elf/stackguard-macros.h is wrong for us (but not + used anywhere apart from elf/tst-stackguard1.c, I think). + +After commit a9538892adfbb9f092e0bb14ff3a1703973968af, it's +`sysdeps/i386/stackguard-macros.h`; problem remains. + + __thread __locale_t __libc_tsd_LOCALE = &_nl_global_locale; + -- this means that a __libc_tsd_LOCALE values will be in the TLS + segment, and this is what is being accessed from the assembler code + with %gs:__libc_tsd_LOCALE@NTPOFF, and the linker will resolve this. + yes + see in the nm output, the libc_tsd symbols + these provide the offsets + youpi: Thank you, I'm now understanding this part of TLS + much better. + have you had a look at the tls.pdf from Uli ? + all the gory details are there :) + +Commit c61b4d41c9647a54a329aa021341c0eb032b793e, [[!sourceware_PR 15754]], adds +`sysdeps/i386/stackguard-macros.h:POINTER_CHK_GUARD`, which is not correct for +us (at the moment), but it also shouldn't cause any harm, as this file is only +used in `elf/tst-ptrguard1.c` and `elf/tst-stackguard1.c`, which now will fail +to build for us, as we don't have a `pointer_guard` member in +`sysdeps/mach/hurd/tls.h:tcbhead_t`. + +We don't define `THREAD_SET_POINTER_GUARD`. -- cgit v1.2.3