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Make .debug_frame support optional.

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Because these code paths use malloc and stdio, they could
cause deadlocks when we try to unwind stack from inside malloc.
This commit is contained in:
Arun Sharma 2009-03-16 21:21:58 -07:00
parent 638302ed73
commit a2c27a4ab7
2 changed files with 24 additions and 20 deletions
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4
configure.in
View file

@ -124,6 +124,10 @@ if test x$enable_cxx_exceptions = xyes; then
fi
AM_CONDITIONAL([SUPPORT_CXX_EXCEPTIONS], [test x$enable_cxx_exceptions = xyes])
AC_ARG_ENABLE(debug_frame,
[ --enable-debug-frame Load the ".debug_frame" section if available],
[enable_debug_frame=$enableval], [enable_debug_frame=yes])
AM_CONDITIONAL([CONFIG_DEBUG_FRAME], [test x$enable_debug_frame = xyes])
LIBUNWIND___THREAD
save_LDFLAGS="$LDFLAGS"

40
src/dwarf/Gfind_proc_info-lsb.c
View file

@ -92,6 +92,7 @@ linear_search (unw_addr_space_t as, unw_word_t ip,
return -UNW_ENOINFO;
}
#ifdef CONFIG_DEBUG_FRAME
/* Load .debug_frame section from FILE. Allocates and returns space
in *BUF, and sets *BUFSIZE to its size. IS_LOCAL is 1 if using the
local process, in which case we can search the system debug file
@ -132,7 +133,7 @@ load_debug_frame (const char *file, char **buf, size_t *bufsize, int is_local)
sec_hdrs = calloc (ehdr.e_shnum, sizeof (Elf_W (Shdr)));
fread (sec_hdrs, sizeof (Elf_W (Shdr)), ehdr.e_shnum, f);
Debug (4, "loading string table of size %d\n",
Debug (4, "loading string table of size %zd\n",
sec_hdrs[shstrndx].sh_size);
stringtab = malloc (sec_hdrs[shstrndx].sh_size);
fseek (f, sec_hdrs[shstrndx].sh_offset, SEEK_SET);
@ -150,7 +151,7 @@ load_debug_frame (const char *file, char **buf, size_t *bufsize, int is_local)
fseek (f, sec_hdrs[i].sh_offset, SEEK_SET);
fread (*buf, 1, *bufsize, f);
Debug (4, "read %d bytes of .debug_frame from offset %d\n",
Debug (4, "read %zd bytes of .debug_frame from offset %zd\n",
*bufsize, sec_hdrs[i].sh_offset);
}
else if (is_local >= 0 && strcmp (secname, ".gnu_debuglink") == 0)
@ -161,7 +162,7 @@ load_debug_frame (const char *file, char **buf, size_t *bufsize, int is_local)
fseek (f, sec_hdrs[i].sh_offset, SEEK_SET);
fread (linkbuf, 1, linksize, f);
Debug (4, "read %d bytes of .gnu_debuglink from offset %d\n",
Debug (4, "read %zd bytes of .gnu_debuglink from offset %zd\n",
*bufsize, sec_hdrs[i].sh_offset);
}
}
@ -220,36 +221,37 @@ load_debug_frame (const char *file, char **buf, size_t *bufsize, int is_local)
return 0;
}
#else
static int
load_debug_frame (const char *file, char **buf, size_t *bufsize, int is_local)
{
return 1;
}
#endif /* CONFIG_DEBUG_FRAME */
/* Locate the binary which originated the contents of address ADDR. Return
the name of the binary in *name (which is allocated on the heap, and must
be freed by the caller). Returns 0 if a binary is successfully found, or 1
if an error occurs. */
the name of the binary in *name (space is allocated by the caller)
Returns 0 if a binary is successfully found, or 1 if an error occurs. */
static int
find_binary_for_address (unw_word_t ip, char **name)
find_binary_for_address (unw_word_t ip, char *name, size_t name_size)
{
#ifdef __linux
struct map_iterator mi;
char path[PATH_MAX];
int found = 0;
int pid = getpid ();
unsigned long segbase, mapoff, hi;
maps_init (&mi, pid);
while (maps_next (&mi, &segbase, &hi, &mapoff, path, sizeof (path)))
while (maps_next (&mi, &segbase, &hi, &mapoff, name, name_size))
if (ip >= segbase && ip < hi)
{
found = 1;
break;
}
maps_close (&mi);
if (found)
{
*name = strdup (path);
return 0;
}
return ~found;
#endif
return 1;
@ -263,7 +265,8 @@ locate_debug_info (unw_addr_space_t as, struct dl_phdr_info *info,
unw_word_t addr, const char *dlname)
{
struct unw_debug_frame_list *w, *fdesc = 0;
char *name = 0;
char path[PATH_MAX];
char *name = path;
int err;
uint64_t start = 0, end = 0;
char *buf;
@ -284,7 +287,7 @@ locate_debug_info (unw_addr_space_t as, struct dl_phdr_info *info,
if (strcmp (dlname, "") == 0)
{
err = find_binary_for_address (addr, &name);
err = find_binary_for_address (addr, name, sizeof(path));
if (err)
{
Debug (15, "tried to locate binary for 0x%" PRIx64 ", but no luck\n",
@ -334,9 +337,6 @@ locate_debug_info (unw_addr_space_t as, struct dl_phdr_info *info,
as->debug_frames = fdesc;
}
if (name && name != dlname)
free (name);
return fdesc;
}