Modifying inline-frame-cycle-unwind.exp to use `bt -no-filters` produces
the following incorrect backtrace:
#0 inline_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:49
#1 normal_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:32
#2 0x000055555555517f in inline_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:50
#3 normal_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:32
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) FAIL: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 1: backtrace when the unwind is broken at frame 1
The expected output, which we get with `bt`, is:
#0 inline_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:49
#1 normal_func () at .../gdb/gdb/testsuite/gdb.base/inline-frame-cycle-unwind.c:32
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb) PASS: gdb.base/inline-frame-cycle-unwind.exp: cycle at level 1: backtrace when the unwind is broken at frame 1
The cycle checking in `get_prev_frame_maybe_check_cycle` relies on newer
frame ids having already been computed and stashed. Unlike other
frames, frame #0's id does not get computed immediately.
The test passes with `bt` because when applying python frame filters,
the call to `bootstrap_python_frame_filters` happens to compute the id
of frame #0. When `get_prev_frame_maybe_check_cycle` later tries to
stash frame #2's id, the cycle is detected.
The test fails with `bt -no-filters` because frame #0's id has not been
stashed by the time `get_prev_frame_maybe_check_cycle` tries to stash
frame #2's id which succeeds and the cycle is only detected later when
trying to stash frame #4's id. Doing `stepi` after the incorrect
backtrace would then trigger an assertion failure when trying to stash
frame #0's id because it is a duplicate of #2's already stashed id.
In `get_prev_frame_always_1`, if this_frame is inline frame 0, then
compute and stash its frame id before returning the previous frame.
This ensures that the id of inline frame 0 has been stashed before
`get_prev_frame_maybe_check_cycle` is called on older frames.
The test case has been updated to run both `bt` and `bt -no-filters`.
Co-authored-by: Andrew Burgess <aburgess@redhat.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32757
On openSUSE Tumbleweed x86_64, with target board unix/-m32 and test-case
gdb.reverse/recvmsg-reverse.exp, I run into:
...
(gdb) continue^M
Continuing.^M
Process record and replay target doesn't support syscall number 360^M
Process record: failed to record execution log.^M
^M
Program stopped.^M
0xf7fc5575 in __kernel_vsyscall ()^M
(gdb) FAIL: $exp: continue to breakpoint: marker2
...
The syscall number 360 in i386 is for syscall socketpair, as we can see in
arch/x86/entry/syscalls/syscall_32.tbl:
...
<number> <abi> <name> <entry point>
360 i386 socketpair sys_socketpair
...
Function i386_canonicalize_syscall assumes that any syscall below 500 maps to
an identically valued enum in enum gdb_syscall:
...
static enum gdb_syscall
i386_canonicalize_syscall (int syscall)
{
enum { i386_syscall_max = 499 };
if (syscall <= i386_syscall_max)
return (enum gdb_syscall) syscall;
else
return gdb_sys_no_syscall;
}
...
However, that's not the case. The value of gdb_sys_socketpair is not 360,
but 512:
...
enum gdb_syscall {
...
gdb_sys_getrandom = 355,
gdb_sys_statx = 383,
...
gdb_sys_socketpair = 512,
...
Consequently, when record_linux_system_call is called with
syscall == i386_canonicalize_syscall (360), we hit the default case here:
....
switch (syscall)
{
...
default:
gdb_printf (gdb_stderr,
_("Process record and replay target doesn't "
"support syscall number %d\n"), syscall);
return -1;
break;
}
...
rather than hitting the case for gdb_sys_socketpair.
I initially wrote a trivial fix for this, changing the value of
gdb_sys_socketpair to 360. However, Andreas Schwab pointed out that there are
other functions (ppc_canonicalize_syscall and s390_canonicalize_syscall) that
make assumptions about specific values of enum gdb_syscall, and fixing this
for i386 may break things for ppc or s390.
So instead, I decided to rewrite i386_canonicalize_syscall to match the
approach taken in aarch64_canonicalize_syscall, which allows
gdb_sys_socketpair to keep the same value.
So, fix this by:
- adding a new table file gdb/i386-syscalls.def, using a SYSCALL entry for
each syscall, generated from arch/x86/entry/syscalls/syscall_32.tbl,
- using gdb/i386-syscalls.def to define enum i386_syscall, and
- using macros SYSCALL_MAP, SYSCALL_MAP_RENAME and UNSUPPORTED_SYSCALL_MAP to
define the mapping from enum i386_syscall to enum gdb_syscall in
i386_canonicalize_syscall.
I've created the mapping as follows:
- I used arch/x86/entry/syscalls/syscall_32.tbl to generate an initial mapping
using SYSCALL_MAP for each syscall,
- I attempted to compile this and used the compilation errors about
non-existing gdb_sys_ values to change those entries to
UNSUPPORTED_SYSCALL_MAP, which got me a compiling version,
- I reviewed the UNSUPPORTED_SYSCALL_MAP entries, changing to
SYSCALL_MAP_RENAME where necessary,
- I then reviewed syscalls below 500 that mapped to a gdb_syscall value below
500, but not the same, and fixed those using SYSCALL_MAP_RENAME, and
- reviewed the mapping for gdb_syscall entries >= 500.
On the resulting mapping, I was able to do the following sanity check:
...
for (int i = 0; i < 500; ++i)
{
int res = i386_canonicalize_syscall (i);
if (res == i)
continue;
if (res == -1)
continue;
if (res >= 500)
continue;
gdb_assert_not_reached ("");
}
}
...
to make sure that any syscall below 500 either:
- maps to the same number,
- is unsupported, or
- maps to a number >= 500.
Coming back to our original problem, the socket pair syscall is addressed by
an entry:
...
SYSCALL_MAP (socketpair);
...
which maps i386_sys_socketpair (360) to gdb_sys_socketpair (512).
Tested on x86_64-linux with target board unix/-m32.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
PR tdep/32770
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32770
(cherry picked from commit fbfb29b304)
After compiling gdb with -fstack-protector-all, and running test-case
gdb.reverse/getrandom.exp on aarch64-linux, we run into
"Stack smashing detected" in function aarch64_record_asimd_load_store.
This is reported in PR record/32784.
This happens due to an out-of-bounds write to local array record_buf_mem:
...
uint64_t record_buf_mem[24];
...
when recording insn:
...
B+>0xfffff7ff4d10 st1 {v0.16b-v3.16b}, [x0]
...
We can fix this by increasing the array size to 128, but rather than again
hardcoding a size, reimplement record_buf_mem as std::vector.
Tested on aarch64-linux.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32784
(cherry picked from commit 51729ea090)
When running:
$ make check TESTS="gdb.cp/cpexprs-debug-types.exp" RUNTESTFLAGS="--target_board=fission"
I get:
(gdb) break -qualified main
/home/smarchi/src/binutils-gdb/gdb/dwarf2/read.h:295: internal-error: version: Assertion `m_dwarf_version != 0' failed.
The problem is that dwarf2_per_cu objects created in the
read_cutu_die_from_dwo code path never have their DWARF version set. A
seemingly obvious solution would be to add a call to
dwarf2_per_cu::set_version in there (there's a patch in the referenced
PR that does that). However, this comment in
read_comp_units_from_section is a bit scary:
/* Init this asap, to avoid a data race in the set_version in
cutu_reader::cutu_reader (which may be run in parallel for the cooked
index case). */
this_cu->set_version (cu_header.version);
I don't know if a DWO file can be read while the cooked indexer runs, so
if it would be a problem here, but I prefer to be safe than sorry. This
patch side-steps the problem by deleting the DWARF version from
dwarf2_per_cu.
The only users of dwarf2_per_cu::version are the loclists callbacks in
`loc.c`. Add the DWARF version to dwarf2_loclist_baton and modify those
callbacks to get the version from there instead. Initialize that new
field in fill_in_loclist_baton.
I like this approach because there is no version field that is possibly
unset now.
I wasn't keen on doing this at first because I thought it would waste
space, but the dwarf2_loclist_baton has 7 bytes of padding at the end
anyway, so we might as well use that.
Cc: Ricky Zhou <ricky@rzhou.org>
Cc: Tom de Vries <tdevries@suse.de>
Cc: Tom Tromey <tom@tromey.com>
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32309
Change-Id: I30d4ede7d67da5d80ff65c6122f5868e1098ec52
Approved-By: Tom Tromey <tom@tromey.com>
(cherry picked from commit f62cf22157)
Check for target_fileio_read_alloc failure in linux_fill_prpsinfo
before dereferencing buffer. This fixes a segfault in the 'gcore'
command when attached to certain remote targets.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32441
Approved-By: Andrew Burgess <aburgess@redhat.com>
(cherry picked from commit cbc6950a66)
