Adds a new warning to memcheck when realloc is used with a size of 0.
For a long time this has been "implementation defined" and so
non-portable. With C23 it will become UB.
Also adds a switch to turn off the error generation and a
second switch to select between the most common
"implementation" behaviours. The defaults for this second
switch are baked in at build time.
It returns NULL and 0 status whilst most other platforms
allocatae some undefined amount of memory (which is allowed
by posix).
Update the posix_memalign test as well.
Finally remove some clang warnings about alignment.
This is the first part of
Bug 466104 aligned_alloc problems, part 1
The bulk of this change is try try to get memalign to be more
platform aware. Previously the Valgrind implementation only
reflected the glibc implementation. That meant non-power of
two alignment values would silently get bumped up to the
next largest power of two. Most other platforms return NULL
and set errno to EINVAL.
There are a few other changes. A couple of the other aligned alloc
functions like valloc were caling the Valgrind memalign. This meant
that there weould be an extra Valgrind memalign in any error
callstacks. Now these functions call the allocator directly.
The memcheck memalign2 testcase has been redone. The memalign
parts moved out to per-platform versions and the tescase
itdelf renamed to posix_memalign, since that is all that is left.
I also modified the testcase so that it checks that the
memalign calls check for non-NULL returns, and on platforms
that set errno that it is correctly set. Previously the
test only worked on non-glibc because NULL & alignment is
zero. The platform versions have been tested on glibc,
MUSL, FreeBSD and OpenIndiana and should hopefully run OK
both under memcheck and standalone.
There is stil quite a lot that is NOT done
1. I'm not certain that implementations allocate more memory
and/or use a wider alignment. It doesn't help that almost
universally the memalign implementations are badly
documented, undocumented or buggy.
2. We don't handle very large alignment requests well.
Most implementations will fail and set EINVAL if the
alignment is over half the memory space. Valgrind will
core panic if an aligmnt of over 16Mbytes is requested.
3. We don't generate any memcheck errors for invalid values
of alignment. That's planned in Part 2.
4. The code is static and fixed at compile time. That means that
if you are using MUSL with a glibc-built Valgrind you
will still get glibc memalign behaviour.
I'll wait to see if there are any requests before trying
to make the behaviour selectable at runtime.
On FreeBSD, Firefox uses the kern.proc.pathname.PID sysctl
to get the binary path (where PID can be the actual pid
or -1). The user path is /usr/local/bin/firefox which is
a symlink to /usr/local/lib/firefox/firefox.
This was failing because we were not handling this MIB.
That meant that the sysctl returned the path for the
binary of the running tool (e.g.,
/home/paulf/scratch/valgrind/memcheck/memcheck-amd64-freebsd).
Firefox looks for files in the same directory.
Since it was the wrong directory it failed to find them and
exited.
I also noticed a lot of _umtx_op errors. On analysis they
are spurious. The wake ops take an "obj" argument, a pointer
to a variable. They only use the address as a key for
lookups and don't read the contents.
There is quite a lot of stuff here.
The problem is that setproctitle and kern.ps_strings were using the Valgrind host auxv
rather than the guest. The proposed patch would have just ignored those memory ranges.
I've gone a fair bit further than that
1. refactored the initimg code for building the client auxv. Previously we were
simply ignoring any non-scalar entries. Now we copy most of thse as well.
That means that 'strtab' built on the client stack no longet only contains
strings, at can also now contain binary structures. Note I was a bit
concerned that there may be some alignment issues, but I haven't seen any
problems so far.
2. Added intercepts to sysctl and sysctlbyname for kern.ps_strings, then find
AT_PS_STRINGS from the client auxv that is now usable from step 1.
3. Some refactoring of sysctl and sysctlbyname syscall wrappers. More to do
there!
4. Added a setproctitle testcase (that also tests the sysctls).
5. Updated the auxv testcase now that more AT_* entries are handled.
These concern auxv, swapoff and fcntl F_KINFO
I wanted to use the new fcntl K_INFO to replace the existing
horrible implementation of resolve_filename, but it seems to
have change the behaviour for redirected files. Several
fdleak regtests fail because stdout resolves to an empty
string.
I've made these changes only for FreeBSD and Solaris for the moment.
I don't know what should be done on Linux for aligned_alloc/memalign.
The current Valgrind code refects the glibc implementation, but not
what the documentation says.
The syscall to realpathat was missing the buffer size argument.
By luck, no problem on amd64 but this failed on x86.
This adds the argument and a filter for the errors (size_t can be 4 or 8 bytes)
Adds syscall wrappers for __specialfd and __realpathat.
Also remove kernel dependency on COMPAT_FREEBSD10.
This change also reorganizes somewhat the scalar test
and adds configure time checks for the FreeBSD version,
allowing regression tests to be compiled depending on the
FreeBSD release.
From now on, scalar.c will contain syscalls for FreeBSD 11 and 12
and subsequent releases will get their own scalar, starting with
scalar_13_plus.c.
Also make drd/tests/shared_timed_mutex more robust
Already not great using time delays, but the test seems
to fail intermittently due to spurious wakeups. So instead
of railing straight away, make it "three strikes and you're out".
Files in the root directory
Several Makefile.am files that have dependencies on FreeBSD autoconf
variables. Included a few new filter files to act as placeholders
to create new freebsd subdirectories.
Updated NEWS with the FreeBSD bugzilla items plus a couple of other
items fixed indirectly.
