Just pass potentially NULL pointers to free() in the error path in
load_debug_frame(). Saved 40 bytes of code in libunwind.so on ARM -O2
thumb build at the expense of slightly slower execution.
Since the dl_iterate_phdr is required for local unwinding only the use of
struct dl_phdr_info can be eliminated in case libunwind gets compiled for
remote unwinding. This enhances libunwinds portability to targets that
don't provide any dl_iterate_phdr functionality.
Signed-off-by: Ken Werner <ken.werner@linaro.org>
Exclude <link.h> because it is only required for local unwinding when
iterating over the program headers.
Have the following DWARF related functions available in case of
UNW_REMOTE_ONLY because they are used by libunwind-ptrace:
dwarf_find_debug_frame
locate_debug_info
find_binary_for_address
load_debug_frame
debug_frame_tab_new
debug_frame_tab_append
debug_frame_tab_shrink
debug_frame_tab_compare
Signed-off-by: Ken Werner <ken.werner@linaro.org>
Rename the dwarf dl_iterate_phdr callback routine and the callback_data
structure to dwarf_callback and dwarf_callback_data. Make it available
within libunwind by declaring the two at the dwarf.h header file.
Signed-off-by: Ken Werner <ken.werner@linaro.org>
Current implementation fails to find separate debug symbols when
.gnu_debuglink is set to the same name of the target ELF basename
(e.g. "libc.so.6" for /lib/libc.so.6). This patch fixes this by ignoring
separate debug files that contain a .gnu_debuglink section.
It also fixes a small typo in a related Debug() line.
Signed-off-by: Andris Zeila <andris.zeila@accenture.com>
Currently, libunwind allocates several PATH_MAX entries on stack, while
trying to find a binary via /proc/.../maps.
However stack space may be at premium (especially when sigaltstack is used),
and PATH_MAX on Linux is 4096, while SIGSTKSZ is only 8192 on x86.
Attached patch eliminates multiple PATH_MAX stack allocations, and simplifies
code in maps_next, at the cost of being unable to do anything if we can't
mmap one page. It appears to me that under such low-memory conditions,
libunwind will fail shortly elsewhere anyway.
This patch also disables more of debug_frame-handling code when
CONFIG_DEBUG_FRAME is undefined.
Tested on Linux/x86_64 with and without CONFIG_DEBUG_FRAME, no regressions.
2004/11/17 02:43:39-08:00 mostang.com!davidm
(struct callback_data): New structure.
(linear_search): New function.
(callback): Convert to getting auxiliary info passed via a pointer to
a callback_data structure, rather than an unw_dyn_info_t
structure.
Keep track of the maximum load address in max_load_addr.
If an object doesn't have a binary search-table, fall back
on a linear search.
(dwarf_find_proc_info): Fill in callback-data structure before calling
dl_iterate_phdr(). Upon returning, check whether
cb_data.single_fde is set and, if so, return directly, without
searching the DWARF unwind-table.
(dwarf_search_unwind_table): Adjust for renaming of
dwarf_parse_fde() to dwarf_extract_proc_info_from_fde().
If IP doesn't fall into the IP-range of the FDE-entry found
by the search, return UNW_ENOINFO.
(Logical change 1.290)
Drop DWARF-parsing debug prints from level 16 to 15.
(struct table_entry): Change member types from unw_word_t to int32_t. The members
need to be of a signed type and forcing them to 32 bits makes the type
work for both 32-bit and 64-bit executables (up to 4GB of text-size).
(callback): Only allow search tables which have 32-bit members.
Fix initialization of di->u.rti.table_len to express table-length as a count
of unw_word_t, as it's defined to be (we get lucky here: even with 32-bit
members, each table-entry contains two members so we're guaranteed that the
table has a size that is an integer-multiple of unw_word_t even on 64-bit
platforms).
(lookup): Change type of "rel_ip" from unw_word_t to int32_t. Simplify the
code a bit.
(remote_read): Delete.
(remote_lookup): Use dwarf_reads32() instead of remote_read() to read out table
members. Simplify code a bit.
(Logical change 1.248)
