From 5a9504831f3fa1ef3be334036c93da30150fde55 Mon Sep 17 00:00:00 2001 From: Fabrice Fontaine Date: Sun, 18 Apr 2021 13:42:53 +0200 Subject: [PATCH] package/m4: fix build with glibc 2.34 m4 fails to build with glibc 2.34 because SIGSTKSZ is now a run-time variable since https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=6c57d320484988e87e446e2e60ce42816bf51d53 So backport an upstream patch from gnulib, see: https://lists.gnu.org/archive/html/bug-m4/2021-03/msg00015.html An other option would have been to apply patch from https://lists.gnu.org/archive/html/bug-m4/2021-03/msg00024.html but no feedback was received on this patch Fixes: - https://bugs.buildroot.org/show_bug.cgi?id=13721 Signed-off-by: Fabrice Fontaine Signed-off-by: Thomas Petazzoni --- .../m4/0003-c-stack-stop-using-SIGSTKSZ.patch | 106 ++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 package/m4/0003-c-stack-stop-using-SIGSTKSZ.patch diff --git a/package/m4/0003-c-stack-stop-using-SIGSTKSZ.patch b/package/m4/0003-c-stack-stop-using-SIGSTKSZ.patch new file mode 100644 index 0000000000..f262fc818e --- /dev/null +++ b/package/m4/0003-c-stack-stop-using-SIGSTKSZ.patch @@ -0,0 +1,106 @@ +c-stack: stop using SIGSTKSZ + +It’s been proposed to stop making SIGSTKSZ an integer constant: +https://sourceware.org/pipermail/libc-alpha/2020-September/118028.html +Also, using SIGSTKSZ in #if did not conform to current POSIX. +Also, avoiding SIGSTKSZ makes the code simpler and easier to grok. +* lib/c-stack.c (SIGSTKSZ): Remove. +(alternate_signal_stack): Now a 64 KiB array, for simplicity. +All uses changed. + +[Retrieved (and backported) from: +https://git.savannah.gnu.org/cgit/gnulib.git/patch/?id=f9e2b20a12a230efa30f1d479563ae07d276a94b] +Signed-off-by: Fabrice Fontaine + +diff -Nura m4-1.4.18.orig/lib/c-stack.c m4-1.4.18/lib/c-stack.c +--- m4-1.4.18.orig/lib/c-stack.c 2021-04-11 19:12:14.086494029 +0200 ++++ m4-1.4.18/lib/c-stack.c 2021-04-11 19:48:46.316862760 +0200 +@@ -50,15 +50,16 @@ + #if ! HAVE_STACK_T && ! defined stack_t + typedef struct sigaltstack stack_t; + #endif +-#ifndef SIGSTKSZ +-# define SIGSTKSZ 16384 +-#elif HAVE_LIBSIGSEGV && SIGSTKSZ < 16384 +-/* libsigsegv 2.6 through 2.8 have a bug where some architectures use +- more than the Linux default of an 8k alternate stack when deciding +- if a fault was caused by stack overflow. */ +-# undef SIGSTKSZ +-# define SIGSTKSZ 16384 +-#endif ++ ++/* Storage for the alternate signal stack. ++ 64 KiB is not too large for Gnulib-using apps, and is large enough ++ for all known platforms. Smaller sizes may run into trouble. ++ For example, libsigsegv 2.6 through 2.8 have a bug where some ++ architectures use more than the Linux default of an 8 KiB alternate ++ stack when deciding if a fault was caused by stack overflow. */ ++static max_align_t alternate_signal_stack[(64 * 1024 ++ + sizeof (max_align_t) - 1) ++ / sizeof (max_align_t)]; + + #include + #include +@@ -128,19 +129,6 @@ + #if (HAVE_SIGALTSTACK && HAVE_DECL_SIGALTSTACK \ + && HAVE_STACK_OVERFLOW_HANDLING) || HAVE_LIBSIGSEGV + +-/* Storage for the alternate signal stack. */ +-static union +-{ +- char buffer[SIGSTKSZ]; +- +- /* These other members are for proper alignment. There's no +- standard way to guarantee stack alignment, but this seems enough +- in practice. */ +- long double ld; +- long l; +- void *p; +-} alternate_signal_stack; +- + static void + null_action (int signo __attribute__ ((unused))) + { +@@ -205,8 +193,8 @@ + + /* Always install the overflow handler. */ + if (stackoverflow_install_handler (overflow_handler, +- alternate_signal_stack.buffer, +- sizeof alternate_signal_stack.buffer)) ++ alternate_signal_stack, ++ sizeof alternate_signal_stack)) + { + errno = ENOTSUP; + return -1; +@@ -279,14 +267,14 @@ + stack_t st; + struct sigaction act; + st.ss_flags = 0; ++ st.ss_sp = alternate_signal_stack; ++ st.ss_size = sizeof alternate_signal_stack; + # if SIGALTSTACK_SS_REVERSED + /* Irix mistakenly treats ss_sp as the upper bound, rather than + lower bound, of the alternate stack. */ +- st.ss_sp = alternate_signal_stack.buffer + SIGSTKSZ - sizeof (void *); +- st.ss_size = sizeof alternate_signal_stack.buffer - sizeof (void *); +-# else +- st.ss_sp = alternate_signal_stack.buffer; +- st.ss_size = sizeof alternate_signal_stack.buffer; ++ st.ss_size -= sizeof (void *); ++ char *ss_sp = st.ss_sp; ++ st.ss_sp = ss_sp + st.ss_size; + # endif + r = sigaltstack (&st, NULL); + if (r != 0) +diff -Nura m4-1.4.18.orig/lib/c-stack.h m4-1.4.18/lib/c-stack.h +--- m4-1.4.18.orig/lib/c-stack.h 2021-04-11 19:12:14.098494042 +0200 ++++ m4-1.4.18/lib/c-stack.h 2021-04-11 19:17:42.138848378 +0200 +@@ -34,7 +34,7 @@ + A null ACTION acts like an action that does nothing. + + ACTION must be async-signal-safe. ACTION together with its callees +- must not require more than SIGSTKSZ bytes of stack space. Also, ++ must not require more than 64 KiB bytes of stack space. Also, + ACTION should not call longjmp, because this implementation does + not guarantee that it is safe to return to the original stack. + -- 2.30.2