Implement _Unwind_FindTableEntry(). This function is part of GCC

for some configurations, but not for FreeBSD (yet?). Have one in
libc in the mean time.

2 files changed, 130 insertions, 0 deletions

diff --git a/lib/libc/ia64/gen/Makefile.inc b/lib/libc/ia64/gen/Makefile.inc
index 4f5dd40..34a96ef 100644
--- a/lib/libc/ia64/gen/Makefile.inc
+++ b/lib/libc/ia64/gen/Makefile.inc
@@ -5,3 +5,7 @@ SRCS+=	sigsetjmp.S fpsetmask.c fpgetmask.c
 SRCS+=	__divdi3.S __divsi3.S __moddi3.S __modsi3.S
 SRCS+=	__udivdi3.S __udivsi3.S __umoddi3.S __umodsi3.S
 SRCS+=	__divdf3.S __divsf3.S
+
+# The following may go away if function _Unwind_FindTableEntry()
+# will be part of GCC.
+SRCS+=	unwind.c
diff --git a/lib/libc/ia64/gen/unwind.c b/lib/libc/ia64/gen/unwind.c
new file mode 100644
index 0000000..566d113
--- /dev/null
+++ b/lib/libc/ia64/gen/unwind.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2002 Marcel Moolenaar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+
+#include <assert.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+
+#include <machine/elf.h>
+
+#ifndef PT_IA_64_UNWIND
+#define PT_IA_64_UNWIND         0x70000001
+#endif
+
+#define	SANITY	0
+
+struct ia64_unwind_entry
+{
+	Elf64_Addr start;
+	Elf64_Addr end;
+	Elf64_Addr descr;
+};
+
+struct ia64_unwind_entry *
+_Unwind_FindTableEntry(const void *pc, unsigned long *pseg, unsigned long *pgp)
+{
+	Dl_info info;
+	Elf_Dyn *dyn;
+	Elf_Ehdr *ehdr;
+	Elf_Phdr *phdr;
+	char *p, *p_top;
+	struct ia64_unwind_entry *unw, *res;
+	register unsigned long gp __asm__("gp");	/* XXX assumes gcc */
+	size_t l, m, r;
+
+	if (!dladdr(pc, &info))
+		return NULL;
+
+	ehdr = (Elf_Ehdr*)info.dli_fbase;
+
+#if SANITY
+	assert(IS_ELF(*ehdr));
+	assert(ehdr->e_ident[EI_CLASS] == ELFCLASS64);
+	assert(ehdr->e_ident[EI_DATA] == ELFDATA2LSB);
+	assert(ehdr->e_machine == EM_IA_64);
+#endif
+
+	*pgp = gp;
+	*pseg = 0UL;
+	res = NULL;
+
+	p = (char*)info.dli_fbase + ehdr->e_phoff;
+	p_top = p + ehdr->e_phnum * ehdr->e_phentsize;
+	while (p < p_top) {
+		phdr = (Elf_Phdr*)p;
+
+		switch (phdr->p_type) {
+		case PT_DYNAMIC:
+			dyn = (Elf_Dyn*)phdr->p_vaddr;
+			while (dyn->d_tag != DT_NULL) {
+				if (dyn->d_tag == DT_PLTGOT) {
+					*pgp = dyn->d_un.d_ptr;
+					break;
+				}
+				dyn++;
+			}
+			break;
+		case PT_LOAD:
+			if (pc >= (void*)phdr->p_vaddr &&
+			    pc < (void*)(phdr->p_vaddr + phdr->p_memsz))
+				*pseg = phdr->p_vaddr;
+			break;
+		case PT_IA_64_UNWIND:
+#if SANITY
+			assert(*pseg != 0UL);
+			assert(res == NULL);
+#endif
+			unw = (struct ia64_unwind_entry*)phdr->p_vaddr;
+			l = 0;
+			r = phdr->p_memsz / sizeof(struct ia64_unwind_entry);
+			while (l < r) {
+				m = (l + r) >> 1;
+				res = unw + m;
+				if (pc < (void*)(res->start + *pseg))
+					r = m;
+				else if (pc >= (void*)(res->end + *pseg))
+					l = m + 1;
+				else
+					break;	/* found */
+			}
+			if (l >= r)
+				res = NULL;
+			break;
+		}
+
+		p += ehdr->e_phentsize;
+	}
+
+	return res;
+}