gcc reports a warning:
m_stacktrace.c:183: warning: ‘xip_verified’ may be used uninitialized in this function
This warning is a false positive:
xip_verified is assigned in the following branch:
if (UNLIKELY(xip_verif >= CFUNWIND)) {
if (xip_verif == CFUNWIND) {
...
} else {
<<<< here xip_verified is initialised >>>>
}
}
xip_verified is then used only if xip_verif > CFUNWIND.
Assign a rubish value to xip_verified to silence gcc.
(??? there are GCC pragmas that can be used to
disable a warning only on a specific line e.g.
something like:
#pragma GCC diagnostic ignored "-Wuninitialized"
Addr xip_verified; // xip for which we have calculated fpverif_uregs
#pragma GCC diagnostic warning "-Wuninitialized"
instead of
Addr xip_verified = 0; // xip for which we have calculated fpverif_uregs
// 0 assigned to silence false positive -Wuninitialized warning
but the #pragma technique seems not used currently.
So, using the bypass by assigning a rubbish value
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13282
* other platforms (e.g. amd64) are first trying to unwind
with cfi info, then with the fp chain.
* fp unwind when code is compiled without frame pointer can
fail and give incomplete stack traces (often terminating
with a random program counter, causing a huge amount of
recorded stack traces).
This patch improves unwinding on x86 by:
* first time an IP is unwound, do the unwind both with
CFI technique and with fp technique.
If results are identical, IP is inserted in a cache of
'fp unwindable' IP
* following unwind of the same IP are then done directly
either with fp unwind or with cfi, depending on the
cached result of the check done during first unwind.
The cache is needed so as to avoid as much as possible cfi unwind,
as this is significantly slower than fp unwind.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13280
(useful to check the sanity of valgrind on request and/or from GDB,
when an error is reported by the tool).
Also re-order the NEWS entries to put the internals things after
the user level new functions.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13262
found by Coverity's checker.
Also fix another missing break XEN_SYSCTL_numainfo found by via a
by-eye check. This one is at the end of the switch so it is benign.
Patch by Ian Campbell <ian.campbell@citrix.com>.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13251
One issue has been reported on the mailing list by Ilya Smelykh, and the second
issue has been found in development for MIPS64.
The change modifies the way we detect target-arch by reading host_cpu from
config.log rather than asking the toolchain.
Also, for MIPS64, we use:
--section-start=.MIPS.options=$ala
while for o32 we still use:
--section-start=.reginfo=$ala
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13249
In a big applications, some recursive algorithms have created
hundreds of thousands of stacktraces, taking a lot of memory.
Option --merge-recursive-frames=<number> tells Valgrind to
detect and merge (collapse) recursive calls when recording stack traces.
The value is changeable using the monitor command
'v.set merge-recursive-frames'.
Also, this provides a new client request: VALGRIND_MONITOR_COMMAND
allowing to execute a gdbsrv monitor command from the client
program.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13246
This generalises the "perm_malloc" function which was in ms_main.c
The new VG_(perm_malloc) is used in ms_main.c
and for execontext : when there are a lot of execontext, this
can save significant memory.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13238
This change is based on rumours/legends/oral transmission of experience/...
that prime nrs are good to use for hash table size :).
If someone has a (short) explanation about why this is useful,
that will be welcome.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13237
Two fixes could be done:
Either we fix the comments
or we increase N_FRAMES to be rather VG_DEEPEST_BACKTRACE.
We fix the comment for the following reason:
This is (at least for the moment) not performance critical.
as this is only called when an error is reported.
However, searching for local vars is extremely costly.
It is unlikely that an error is reported for a stack variable
which is more than 8 frames deeper than theframe in which
it is detected.
So, fix the comment, waiting for a complaint that a deeper
variable is not properly described.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13235
All calls to VG_(unknown_SP_update) were recording an execontext
of one IP, useful only for track origin.
This patch implements splits VG_(unknown_SP_update)
in two different functions VG_(unknown_SP_update_w_ECU)
(doing origin tracking) and VG_(unknown_SP_update) (not doing origin tracking).
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13225
The option --keep-stacktraces controls which stack trace(s) to keep for
malloc'd and/or free'd blocks. This can be used to obtain more information
for 'use after free' errors or to decrease Valgrind memory and/or cpu usage
by recording less information for heap blocks.
This fixes 312913 Dangling pointers error should also report the alloc
stack trace.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13223
information about the stack traces recorded by Valgrind.
This can be used to analyse one possible cause of Valgrind high
memory usage for some programs.
At work, a big set of regression tests crashed out of memory under Valgrind.
Two main causes for out of memory were identified:
1. big memory usage for stacktrace (exe contexts) recording by Valgrind
2. big number of partially initialised bytes.
This patch adds a gdbsrv monitor command that output (very) detailed
information about all the recorded exe context.
This has been used to analyse the problem 1. above,
showing the following identified causes for a (too) big nr of execontexts:
A. When the JIT handles an unknown SP update, even when --track-origins=no,
an execontext is (uselessly) created and recorded
to track the (never used) origin of some uninitialised stack memory.
This creates a whole bunch of 'one IP' execontexts.
B. same problem in handling some system calls (at least the brk system
calls always records an origin, even when --track-origins=yes).
C. The Valgrind unwinder cannot properly unwind some stack traces.
It unwinds a few frames, then go bezerk and stops at a "random" IP.
This then causes the same "logical" stacktrace to be truncated
and records thousands of times with this "differentiating" last IP.
For problem cause 2 above ( a lot of partially initialised bytes),
the idea is to similarly add another gdbsrv commands that will output
statistics about which stack traces are causing a lot of uninitialised bytes.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13220
--profile-flags=00000000 now prints summary statistics, one line per
profiled block, but with no translation details. Previously it had
no effect.
--profile-interval=<number> is a new flag that causes the profile data
to be dumped and zeroed every <number> event checks. This makes it
possible to get profile data without waiting for runs to end, and to
get profile data which depends on the current workload etc. If
--profile-interval=0 or is unset, the profile is printed only once, at
the end of the run, as before.
--profile-flags=XXXXXXXX (for at least one nonzero X) prints the
summary lines both at the start and end of the profile, so you don't
have to scroll back up to the top to see the summary.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13213
signal on amd64-linux systems.
The amd64 ABI describes the required alignment on function entry
as follows:
"In other words, the value (%rsp − 8) is always a multiple
of 16 when control is transferred to the function entry point.
So we need to 16 byte align and then subtract an extra 8 bytes
to achieve the correct alignment.
Patch from fjgmacc@gmail.com to fix BZ#280114.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13182
First, use STFLE whenever possible (i.e. for all facilities that
were introduced at the same time STFLE was or later). Turns out,
that is most facilities we're interesting in probing, except long
displacement.
Secondly, remove magic constants denoting facility bits and use
the definition from libvex_s390x_common.h
Thirdly, build up the debugging message that shows the status of
the probed facilities in a generic way so it won't have to be
changed when facilities are added.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13174
284540 Memcheck shouldn't count suppressions matching still-reachable allocations
307465 --show-possibly-lost=no should bring down the error count / exit code
Using the options --show-leak-kinds=kind1,kind2,.. and
--errors-for-leak-kinds=kind1,kind2,.., each leak kind (definite, indirect,
possible, reachable) can now be individually reported and/or counted as
an error.
In a leak suppression entry, an optional line 'match-leak-kinds:'
controls which leak kinds are suppressed by this entry.
This is a.o. useful to avoid definite leaks being "catched"
by a suppression entry aimed at suppressing possibly lost blocks.
Default behaviour is the same as 3.8.1
Old args (--show-reachable and --show-possibly-lost) are still accepted.
Addition of a new test (memcheck/tests/lks) testing the new args
and the new suppression line.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13170
instead checking the shdrs:
The separate .debug file has wrong phdrs. This isn't normally fatal
since .debug files are never directly loaded. But since valgrind
uses the phdrs to locate the build-id it will fail. The attached
patch makes it so that the code falls back to using the shdrs to
locate the NOTE sections so that the buildid can be matched anyway.
Fixes#305431. (Mark Wielaard, mjw@redhat.com)
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13160
specification of an extra directory in which to look for debuginfo
objects. Fixes#310792. (Alex Chiang, achiang@canonical.com)
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13154
This patch changes the way static variables are
recorded by readdwarf3.c (when giving --read-var-info=yes),
improving the way such variables are described.
Currently:
A static variable does not have the DW_AT_external tag.
So, readdwarf3.c does not consider it a global variable.
It is rather considered a "local" variable.
When it is recorded, it is associated to a range of program counters
(the functions in the file where it is visible).
However, even if the static variable is only visible
in the source file where it is declared, it can in reality
be used by any range of program counters, typically
by having the address of the local variable passed
to other functions.
Such local variable can then only be described
when the program counter is in the range of program
counters for which it has been recorded.
However, this (local) description is obtained
by a kludge in debuginfo.c (around line 3285).
This kludge then produces a strange description,
telling that the variable has been declared in
frame 0 of a thread (see second example below).
The kludge is not always able to describe
the address (if the IP of the tid is in another file than
where the variable has been declared).
I suspect the kludge can sometimes describe the var as being
declared in an unrelated thread
(e.g. if an error is triggered by tid 5, but tid1 is by
luck in an IP corresponding to the recorded range).
The patch changes the way a static variable is recorded:
if DW_AT_external tag is found, a variable is marked as global.
If a variable is not external, but is seen when level is 1,
then we record the variable as a global variable (i.e.
with a full IP range).
This improves the way such static variable are described:
* they are described even if being accessed by other files.
* their description is not in an artificial "thread frame".
First example:
**************
a variable cannot be described because it is
accessed by a function in another file:
with the trunk:
==20410== ----------------------------------------------------------------
==20410==
==20410== Possible data race during read of size 4 at 0x600F54 by thread #1
==20410== Locks held: none
==20410== at 0x4007E4: a (abc.c:42)
==20410== by 0x4006BC: main (mabc.c:24)
==20410==
==20410== This conflicts with a previous write of size 4 by thread #2
==20410== Locks held: none
==20410== at 0x4007ED: a (abc.c:42)
==20410== by 0x400651: brussels_fn (mabc.c:9)
==20410== by 0x4C2B54E: mythread_wrapper (hg_intercepts.c:219)
==20410== by 0x4E348C9: start_thread (pthread_create.c:300)
==20410==
==20410== ----------------------------------------------------------------
with the patch:
==4515== ----------------------------------------------------------------
==4515==
==4515== Possible data race during read of size 4 at 0x600F54 by thread #1
==4515== Locks held: none
==4515== at 0x4007E4: a (abc.c:42)
==4515== by 0x4006BC: main (mabc.c:24)
==4515==
==4515== This conflicts with a previous write of size 4 by thread #2
==4515== Locks held: none
==4515== at 0x4007ED: a (abc.c:42)
==4515== by 0x400651: brussels_fn (mabc.c:9)
==4515== by 0x4C2B54E: mythread_wrapper (hg_intercepts.c:219)
==4515== by 0x4E348C9: start_thread (pthread_create.c:300)
==4515==
==4515== Location 0x600f54 is 0 bytes inside global var "static_global"
==4515== declared at mabc.c:4
==4515==
==4515== ----------------------------------------------------------------
Second example:
***************
When the kludge can describe the variable, it is strangely described
as being declared in a frame of a thread, while for sure the declaration
has nothing to do with a thread
With the trunk:
==20410== Location 0x600f68 is 0 bytes inside local var "static_global_a"
==20410== declared at abc.c:3, in frame #0 of thread 1
With the patch:
==4515== Location 0x600f68 is 0 bytes inside global var "static_global_a"
==4515== declared at abc.c:3
#include <stdio.h>
static int static_global_a = 0; //// <<<< this is abc.c:3
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13153
