From f7c399cff5bd04ee9dc117fb6b0f39597dc047c6 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 17 Aug 2013 18:37:18 +0930 Subject: [PATCH] PowerPC SIGSTKSZ http://sourceware.org/ml/libc-alpha/2013-08/msg00093.html This copies the sparc version of sigstack.h, which gives powerpc #define MINSIGSTKSZ 4096 #define SIGSTKSZ 16384 Before the VSX changes, struct rt_sigframe size was 1920 plus 128 for __SIGNAL_FRAMESIZE giving ppc64 exactly the default MINSIGSTKSZ of 2048. After VSX, ucontext increased by 256 bytes. Oops, we're over MINSIGSTKSZ, so powerpc has been using the wrong value for quite a while. Add another ucontext for TM and rt_sigframe is now at 3872, giving actual MINSIGSTKSZ of 4000. The glibc testcase that I was looking at was tst-cancel21, which allocates 2*SIGSTKSZ (not because the test is trying to be conservative, but because the test actually has nested signal stack frames). We blew the allocation by 48 bytes when using current mainline gcc to compile glibc (le ppc64). The required stack depth in _dl_lookup_symbol_x from the top of the next signal frame was 10944 bytes. I guess you'd want to add 288 to that, implying an actual SIGSTKSZ of 11232. * sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h: New file. --- ChangeLog | 4 ++ sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h | 54 +++++++++++++++++++++++++ 2 files changed, 58 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h diff --git a/ChangeLog b/ChangeLog index 07aaa25..03c35b1 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2013-10-04 Alan Modra + * sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h: New file. + +2013-10-04 Alan Modra + * sysdeps/unix/sysv/linux/powerpc/powerpc32/makecontext.S: Use conditional form of branch and link when obtaining pc. * sysdeps/unix/sysv/linux/powerpc/powerpc64/makecontext.S: Likewise. diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h b/sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h new file mode 100644 index 0000000..33be9e8 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/bits/sigstack.h @@ -0,0 +1,54 @@ +/* sigstack, sigaltstack definitions. + Copyright (C) 1998-2013 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#ifndef _SIGNAL_H +# error "Never include this file directly. Use instead" +#endif + + +/* Structure describing a signal stack (obsolete). */ +struct sigstack + { + void *ss_sp; /* Signal stack pointer. */ + int ss_onstack; /* Nonzero if executing on this stack. */ + }; + + +/* Possible values for `ss_flags.'. */ +enum +{ + SS_ONSTACK = 1, +#define SS_ONSTACK SS_ONSTACK + SS_DISABLE +#define SS_DISABLE SS_DISABLE +}; + +/* Minimum stack size for a signal handler. */ +#define MINSIGSTKSZ 4096 + +/* System default stack size. */ +#define SIGSTKSZ 16384 + + +/* Alternate, preferred interface. */ +typedef struct sigaltstack + { + void *ss_sp; + int ss_flags; + size_t ss_size; + } stack_t; -- 2.7.4