ubuntu-buildroot/package/diffutils/0005-sigsegv-Add-support-fo...

59 lines
2.4 KiB
Diff

From 6f2f006185cdeeda997d19d651379bfc6887e394 Mon Sep 17 00:00:00 2001
From: Joel Stanley <joel@jms.id.au>
Date: Mon, 6 Jun 2022 17:14:12 +0930
Subject: [PATCH] sigsegv: Add support for Linux/PowerPC (32-bit) with musl
libc. Reported by Khem Raj <raj.khem@gmail.com> in
<https://lists.gnu.org/archive/html/m4-patches/2022-03/msg00000.html>.
* src/sigsegv.c (SIGSEGV_FAULT_STACKPOINTER): In the Linux/PowerPC
32-bit case, handle musl libc differently.
* modules/sigsegv (Files): Add m4/musl.m4.
(configure.ac): Invoke gl_MUSL_LIBC.
Backported from http://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=2d830e4a792fcd9f614ed08a7f18584b8b21d23b
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
lib/sigsegv.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/lib/sigsegv.c b/lib/sigsegv.c
index da70ffa5fda1..da64d7d0b617 100644
--- a/lib/sigsegv.c
+++ b/lib/sigsegv.c
@@ -227,11 +227,28 @@ int libsigsegv_version = LIBSIGSEGV_VERSION;
# if defined __powerpc64__ || defined __powerpc64_elfv2__ /* 64-bit */
# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.gp_regs[1]
# else /* 32-bit */
-/* both should be equivalent */
-# if 0
-# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.regs->gpr[1]
+# if MUSL_LIBC
+/* musl libc has a different structure of ucontext_t in
+ musl/arch/powerpc/bits/signal.h. */
+/* The glibc comments say:
+ "Different versions of the kernel have stored the registers on signal
+ delivery at different offsets from the ucontext struct. Programs should
+ thus use the uc_mcontext.uc_regs pointer to find where the registers are
+ actually stored." */
+# if 0
+# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.gregs[1]
+# else
+# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_regs->gregs[1]
+# endif
# else
-# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.uc_regs->gregs[1]
+/* Assume the structure of ucontext_t in
+ glibc/sysdeps/unix/sysv/linux/powerpc/sys/ucontext.h. */
+/* Because of the union, both definitions should be equivalent. */
+# if 0
+# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.regs->gpr[1]
+# else
+# define SIGSEGV_FAULT_STACKPOINTER ((ucontext_t *) ucp)->uc_mcontext.uc_regs->gregs[1]
+# endif
# endif
# endif
--
2.35.1