The default implementation provided by __builtin functions
does very weird things.
Uncovered by Philippe's commit r15716.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15734
This implements the interception of all globally public allocation
functions by default. It works by adding a flag to the spec to say the
interception only applies to global functions. Which is set for the
somalloc spec. The librarypath to match is set to "*" unless the user
overrides it. Then each DiSym keeps track of whether the symbol is local
or global. For a spec which has isGlobal set only isGlobal symbols will
match.
Note that because of padding to keep the addresses in DiSym aligned the
addition of the extra bool isGlobal doesn't actually grow the struct.
The comments explain how the struct could be made more compact on 32bit
systems, but this isn't as easy on 64bit systems. So I didn't try to do
that in this patch.
For ELF symbols keeping track of which are global is trivial. For pdb I
had to guess and made only the "Public" symbols global. I don't know
how/if macho keeps track of global symbols or not. For now I just mark
all of them local (which just means things work as previously on platforms
that use machos, no non-system symbols are matches by default for somalloc
unless the user explicitly tells which library name to match).
Included are two testcases for shared libraries (wrapmalloc) and staticly
linked (wrapmallocstatic) malloc/free overrides that depend on the new
default. One existing testcase (new_override) was adjusted to explicitly
not use the new somalloc default because it depends on a user defined
new implementation that has side-effects and should explicitly not be
intercepted.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15726
All memory dereferences during leak search are checked either with
aspacemgr or using the VA-bits.
So, in theory, no memory fault should occur.
However, the leak search is done so as to resist to e.g.
- desynchronisation between the real pages mapped and the aspacemgr state.
- client pages mprotected against reading
- any other reason why dereferencing a client address would fail.
So, the function lc_scan_memory installs a fault catcher that
is called if a memory fault signal is raised during memory scan.
However, memory dereference is also done in the function heuristic_reachedness.
So, this function must also resist to memory fault.
This patch also installs a fault catcher for the function heuristic_reachedness.
More in details, the following changes are done:
* pub_tool_signal.h and m_signals.c :
VG_(set_fault_catcher) now returns the previously set fault catcher.
This is needed so that heuristic_reachedness/lc_scan_memory can save
and restore the previous fault catcher.
* mc_leakcheck.c:
Addition of leak_search_fault_catcher that contains the common
code for the (currently 2) fault catchers used during leak search.
* Modification of heuristic_reachedness and lc_scan_memory:
Add 2 (small) specific fault catcher that are calling the common
leak_search_fault_catcher.
* The way sigprocmask is handled has been changed:
Before this patch, lc_scan_memory was saving/restoring the procsigmask
for each scanned block (and was restoring it when the fault catcher
was longjmp-ing back to lc_scan_memory in case of SEGV or BUS.
This was causing 2 system calls for each block scanned.
Now, lc_scan_memory and heuristic_reachedness are not saving/restoring
the procmask: the work to reset the sigprocmask is only done
in leak_search_fault_catcher. This is more efficient as no syscall
anymore is done during leak search, except for (normally) unfrequent
SIGSEGV/BUS. It is also simpler as signal handling is now done at
a single place.
It is ok to reset the procmask (in fact, just remove the caught signal
from the process sigmask) as during leak search, no other activity than
the leak search is on-going, and so no other SEGV/BUS can be received
while the handler runs.
This gives moderate speed improvements for applications allocating a lot of
blocks (about 10% improvement when leak searching in 1 million small blocks).
Test case (slightly modified) by Matthias Schwarzott.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15716
that the prerequisites for lock elision are met. Then it may use TBEGIN
and other transactional-execution instructions which are not implemented
by Valgrind. Likewise, the upcoming glibc 2.23 will exploit vector
instructions if they are advertised by HWCAP; and those are currently
not implemented by Valgrind either. In general, the increased use of
ifunc may lead to more such cases in the future.
This patch suppresses the advertising of those hardware features via
HWCAP which are either not known to Valgrind or currently unsupported.
Patch by Andreas Arnez (arnez@linux.vnet.ibm.com).
Fixes BZ #353680.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15702
Explanation by Matthias Schwarzott:
The linker will request an executable stack as soon as at least one
object file, that is linked in, wants an executable stack.
And the absence of the
.section .note.GNU-stack."",@progbits
is enough to tell the linker that an executable stack is needed.
So even an empty asm-file must at least contain this statement to not
force executable stacks on the whole executable.
* Define a helper macro MARK_STACK_NO_EXEC that disables the
executable stack.
* Instantiate this macro unconditionally at the end of each asm file.
Patch by Matthias Schwarzott <zzam@gentoo.org>.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15692
in the auxiliary vector.
This is possible as Solaris 12 kernel now creates auxv even
for statically linked binaries.
n-i-bz
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15682
Solaris runtime linker allows to run dynamically linked programs indirectly, as:
ld.so.1 <dynamic_executable>
This is now possible under Valgrind as well.
Fixes BZ#351858.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15607
Ensure that no code is generated for client requests on x32.
From: Matthias Schwarzott <zzam@gentoo.org>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15526
This ioctl argument struct has never had such a member.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15386
More recent Xen toolstacks use this for the SID_TO_CONTEXT operation
only, even when XSM is not in use.
XSM is actually an abstraction layer, of which the only current
implementation is FLASK. So this blindly assumes that the backend is
FLASK. Should another XSM backend be invented then we will have to
sort of detecting the correct one.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15384
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15381
XENMEM_machphys_compat_mfn_list is functionally identical to
XENMEM_machphys_mfn_list but returns a different list from Xen.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15379
