Commit dbce594d33
added unconditional dwarf usage into unw_get_proc_name.
Unfortunately ia64 is the only architecture that
does not support it in libunwind (configure.ac):
```
if test x$target_arch != xia64; then
use_dwarf=yes
else
use_dwarf=no
fi
```
As a result build fails on ia64 as:
```
ia64-unknown-linux-gnu-gcc ... -c mi/Lget_proc_name.c ...
In file included from mi/Lget_proc_name.c:4:0:
mi/Gget_proc_name.c: In function '_ULia64_get_proc_name':
mi/Gget_proc_name.c:107:8: error: 'struct cursor' has no member named 'dwarf'
if (c->dwarf.use_prev_instr)
^~
mi/Gget_proc_name.c:111:8: error: 'struct cursor' has no member named 'dwarf'
if (c->dwarf.use_prev_instr && offp != NULL && error == 0)
^~
```
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
In file included from src/ia64/Ginit_remote.c:26:0:
src/ia64/init.h: In function 'common_init':
src/ia64/init.h:32:12: warning: variable 'natp' set but not used [-Wunused-but-set-variable]
Change the way we generate the cursor header files, so that we do not
need to invoke IA64 binaries, which would fail when cross-compiling
libunwind.
Adopt the strategy used in the Linux kernel build system, and parse our
annotated offset information from the assembler file produced by the
compiler.
- Add tdep macro for {dwarf,ia64}_find_unwind_table so that ia64
doesn't try to use dwarf code.
- Fix extraneous #if.
- Fix mistyped filename in Makefile.am.
- Link ia64-specific tests with correct libraries.
Signed-off-by: Martin Milata <mmilata@redhat.com>
Greetings,
We use libunwind just for stack traces (I suspect many others do as well).
The use pattern is:
GetStackTrace(void** result, int max_depth)
{
...
unw_getcontext(&uc);
unw_init_local(&cursor, &uc);
while (n < max_depth) {
if (unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip) < 0) {
break;
}
result[n++] = ip;
if (unw_step(&cursor) <= 0) {
break;
}
}
Given this usage, it is quite convenient for us to block signals (or
prevent signal handlers from re-entering libunwind by other means) at the
"top level", which makes most of the sigprocmask calls performed by
libunwind itself unneccessary.
The second patch in this series adds a configure option which removes most
of the sigprocmask calls.
Attached patch is a preliminary for it -- consolidating all of the
"sigprocmask; mutex_lock;" sequences into lock_acquire and "mutex_unlock;
sigprocmask;" sequences into lock_release.
Thanks,
--
Paul Pluzhnikov
commit 402d15b123d54a7669db7cf17a76dd315094e472
Author: Paul Pluzhnikov <ppluzhnikov@google.com>
Date: Mon Sep 21 10:18:28 2009 -0700
Replace "sigprocmask + mutext_lock" with a single lock_acquire.
Likewise, replace "mutext_unlock + sigprocmask" with lock_release.
This rule (no IP adjustment on ia64) may be correct for locating the right FDE.
Unfortunately the same adjusted/unadjusted return address is being used also by
__gxx_personality_v0() to locate the right call-site (the try {} block) for
unwinding. And this case is already sensitive for off-by-one PC values.
Unlike the FDE location where the function prologue + epilogue make it immune
against off-by-one PC calculations.
Therefore suggesting to unify it with non-ia64 case.
Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Provide a special implementation for ia64, because the unwind
information is such that an IP adjustment is not necessary before
looking up unwind info.
Bad things happen if libunwind only provides parts of the ABI and
the rest come from libgcc.
Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>
as "weak". Since the elf-support is in the library anyhow, this serves
no purpose and in fact causes problem because the weak reference alone
is not enough to pull in the ELF-code from an archive file, causing to
spurious failures of get_proc_name.
On some systems executable stacks are denied. Since libunwind and the
tests don't actually need executable stacks this patch marks all
assembly files as not needing it.
The original patch comes from frysk:
2007-04-05 Jan Kratochvil <jan.kratochvil@redhat.com>
* src/hppa/getcontext.S, src/hppa/setcontext.S, src/hppa/siglongjmp.S,
src/ia64/Ginstall_cursor.S, src/ia64/Linstall_cursor.S,
src/ia64/dyn_info_list.S, src/ia64/getcontext.S, src/ia64/longjmp.S,
src/ia64/setjmp.S, src/ia64/siglongjmp.S, src/ia64/sigsetjmp.S,
src/ppc64/longjmp.S, src/ppc64/siglongjmp.S, src/x86/longjmp.S,
src/x86/siglongjmp.S, src/x86_64/longjmp.S, src/x86_64/setcontext.S,
src/x86_64/siglongjmp.S: Stack should be non-executable, for SELinux.
I added a couple more markers for new files in current libunwind.
Before this patch you would get the following on selinux enabled
systems without allow_exec_stack: error while loading shared
libraries:
libunwind.so.7: cannot enable executable stack as shared object
requires: Permission denied
After the patch that error disappears and all test results are similar
to the results on systems without executable stack protection.
routine and add address-space argument. This is needed because on
PPC64, a the function-name symbol refers to a function descriptor
(unlike, for example, on ia64, where the @fptr() operator is needed to
refer to a function descriptor). Thus, in order to look up the name
of a function, we need to dereference the function descriptor. To
make matters more "interesting", the function descriptors are normally
resolved by the dynamic linker, so we can't get their values from the
ELF file. Instead, we have to read them from the running image, hence
the need for the address-space argument.
(get_initial_stack_pointers): Likewise.
(unw_init_local): Use new functions to make code more readable and add
Linux kernel support.
(Logical change 1.296)
Include "libunwind_i.h" instead of "internal.h" and "tdep.h".
Define rbs_cover_and_flush() only for the !UNW_REMOTE_ONLY case.
(ia64_is_big_endian): New macro.
(ia64_get_abi): Likewise.
(ia64_set_abi): Likewise.
(ia64_get_abi_marker): Likewise.
(Logical change 1.294)
