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
From: Ian Campbell <Ian.Campbell@citrix.com>
Under Xen the toolstack is responsible for managing the domains in
the system, e.g. creating, destroying, and otherwise manipulating
them.
To do this it uses a number of ioctls on the /proc/xen/privcmd
device. Most of these (the MMAPBATCH ones) simply set things up such
that a subsequenct mmap call will map the desired guest memory. Since
valgrind has no way of knowing what the memory contains we assume
that it is all initialised (to do otherwise would require valgrind to
be observing the complete state of the system and not just the given
process).
The most interesting ioctl is XEN_IOCTL_PRIVCMD_HYPERCALL which
allows the toolstack to make arbitrary hypercalls. Although the
mechanism here is specific to the OS of the guest running the
toolstack the hypercalls themselves are defined solely by the
hypervisor. Therefore I have split support for this ioctl into a part
in syswrap-linux.c which handles the ioctl itself and passes things
onto a new syswrap-xen.c which handles the specifics of the
hypercalls themselves. Porting this to another OS should just be a
matter of wiring up syswrap-$OS.c to decode the ioctl and call into
syswrap-xen.c. In the future we may want to split this into
syswrap-$ARCH-xen.c but for now this is x86 only.
The hypercall coverage here is pretty small but is enough to get
reasonable(-ish) results out of the xl toolstack when listing,
creating and destroying domains.
One issue is that the hypercalls which are exlusively used by the
toolstacks (as opposed to those used by guest operating systems) are
not considered a stable ABI, since the hypervisor and the lowlevel
tools are considered a matched pair. This covers the sysctl and
domctl hypercalls which are a fairly large chunk of the support
here. I'm not sure how to solve this without invoking a massive
amount of duplication. Right now this targets the Xen unstable
interface (which will shortly be released as Xen 4.2), perhaps I can
get away with deferring this problem until the first change .
On the plus side the vast majority of hypercalls are not of interest
to the toolstack (they are used by guests) so we can get away without
implementing them.
Note: a hypercall only reads as many words from the ioctl arg
struct as there are actual arguments to that hypercall and the
toolstack only initialises the arguments which are used. However
there is no space in the DEFN_PRE_TEMPLATE prototype to allow this to
be communicated from syswrap-xen.c back to syswrap-linux.c. Since a
hypercall can have at most 5 arguments I have hackily stolen ARG8 for
this purpose.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12963
This is a slightly modified version of a patch provided by Petar Jovanovic
<petar.jovanovic@rt-rk.com>.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12960
di->soname was not freed, so was leaked when debug info is removed.
free(soname) added in free_Debuginfo, after having verified
and then ensured that all soname are allocated in dinfo.
regtested on deb6/amd64
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12442
(Rusty Russell, rusty@rustcorp.com.au)
tdb uses fcntl locks and mmap, and some of the tests fail under valgrind.
strace showed valgrind opening the tdb file, reading 1024 bytes, then closing
it. This is not allowed: POSIX says if you open and close a file, all fcntl
locks on it are dropped (insane, yes).
Finally got around to hacking the source to track this down: di_notify_mmap is
doing the damage. The simplest fix was to hand in an optional fd for it to
use, then have it do pread.
I had to fix your pread; surely this should seek back even if the platform
doesn't have pread support?
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12224
* configure.in support
* new supp file darwin11.supp
* comment out many intercepts in mc_replace_strmem.c and
vg_replace_malloc.c that are apparently unnecessary for Darwin
* add minimal handling for the following new syscalls and mach traps:
mach_port_set_context
task_get_exception_ports
getaudit_addr
psynch_mutexwait
psynch_mutexdrop
psynch_cvbroad
psynch_cvsignal
psynch_cvwait
psynch_rw_rdlock
psynch_rw_wrlock
psynch_rw_unlock
psynch_cvclrprepost
* wqthread_hijack on amd64-darwin: deal with
tst->os_state.pthread having an apparently different offset,
which caused an assertion failure
* m_debuginfo: for 32 bit processes on Lion, use the DebugInfoFSM
cleanup added in r12041/12042 to handle apparently new dyld
behaviour, which is to map text areas r-- first and only
vm_protect them later to r-x.
The following cleanups remain to be done
* remove apparently pointless, commented out wrapper macro
invokations in mc_replace_strmem.c, eg
//MEMMOVE(VG_Z_DYLD, memmove)
(or determine that they are still necessary, and uncomment)
* ditto in vg_replace_malloc.c, plus general VGO_darwin cleanups
there
* write proper syscall wrappers for
mach_port_set_context
task_get_exception_ports
getaudit_addr
psynch_mutexwait
psynch_mutexdrop
psynch_cvbroad
psynch_cvsignal
psynch_cvwait
psynch_rw_rdlock
psynch_rw_wrlock
psynch_rw_unlock
psynch_cvclrprepost
These are currently just no-ops and may be causing Memcheck to
report false undef-value errors
* figure out why it doesn't work properly unless built with gcc-4.2 on
Lion.
gcc-4.2 is the "normal" gcc (i686-apple-darwin11-gcc-4.2.1). Plain
gcc is the hybrid gcc-front-end clang-back-end thing
(i686-apple-darwin11-llvm-gcc-4.2). Whereas on Snow Leopard, plain
gcc is the normal gcc.
The symptoms of the failure are that wqthread_hijack in
syswrap-amd64-linux.c hits this /*NOTREACHED*/ vg_assert(0); right
at the end (you need a pretty complex threaded app to trigger this),
which makes me think that either ML_(wqthread_continue_NORETURN) or
call_on_new_stack_0_1 do return, which they are not expected to.
* figure out if some of the uninitialised value errors reported in
system libraries on are caused by Memcheck being confused by LLVM
generated code, as per bug #242137
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12043
contains a bunch of fields which are used as a very simple state
machine that observes mmap calls and decides when to read debuginfo
for the associated file. This change moves these fields into their
own structure, struct _DebugInfoFSM, for cleanness, so as to make it
clear they have a common purpose.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12041
with only one symbol. Instead, allow an address to have arbitrarily
many names. This reflects reality better, particularly for systemy
libraries such as glibc and ld.so, and is background work needed for
fixing #275284. This is not in itself a fix for #275284. A followup
commit to un-break compilation on OSX will follow shortly.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11981
tid == VG_INVALID_THREADID rather than an uninitialised ThreadId.
Also in format_message, improve precondition assertions for
frameNo and tid.
There's no error in the current code since if frameNo == -1 then
tid is unused, but it caused IBM's BEAM checker to complain.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11723
__builtin_setjmp and __builtin_longjmp so that they can be selectively
replaced, on a platform by platform basis. Does not change any
functionality. Related to #259977.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11687
* better progress messages, to make it clear that reading of a
PDB is finished, and how much stuff was read from it
* don't mmap PDB files to read them -- instead use VG_(read).
This is because CIFS filesystem mounting only works reliably on
Linux when mounted with option '-o directio', and that
disallows mmap-ing files.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11482
behave more like the original proposal in #245535. This makes it
more flexible and general. Also rename it.
* new name is --fullpath-after=
* allow multiple instances of --fullpath-after=
* don't require the specified strings to be prefixes, only substrings
But retain the elegant backwards-compatibility trick in Bart's r11312
commit: if --fullpath-after= is not specified at all, then behave
exactly as before.
Fixes#245535. A mixture of patches from Bart Van Assche
(bart.vanassche@gmail.com), Alexander Potapenko (glider@google.com),
and me (integration and documentation).
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11430
unbreaks the build breakage on Darwin introduced in r11397, which
was a fix for #234064. The breakage was subsequently reported
in #253420 and #253452, which this commit fixes.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11406
read debuginfo from, use VKI_O_LARGEFILE, so as to ensure the open
succeeds for large files on 32-bit systems. Fixes#234064.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11397
knows how to unwind. This is important when unwinding Thumb code
the CFA is often stated as being at some offset from r7.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11377
any symbol in the r-x mapped segment to be a valid candidate. This
relaxes the filtering criterion slightly, makes it consistent with
other is-it-text? checks. Some addresses which before didn't get
mapped to anything are now correctly mapped to "vtable for Foo"
symbols.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11104
method of doing "strings file.dll | egrep '\.pdb|\.PDB'".
Distantly derived from a patch by leiz@ucla.edu. Fixes#222902,
although I still would prefer to do this the proper way, by parsing
the PE file properly.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11039
minute older than the PE (the .exe/.dll it describes) even though this
doesn't seem particularly safe. Partially fixes#190675.
(patch from Dan Kegel)
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11033
too. This is a first step towards making not be completely
x86/amd64-linux specific, and so replaces some x86/amd64-specific
stuff with more general constructions:
* structure 'DiCfSI', into which the info is summarised, has been
made target-specific (ugh), since the sets of registers to be
unwound differ on different targets.
* enum CfiReg and the CFIC_ constants have been expanded
accordingly, to handle both arm and x86/amd64 registers.
The abbreviation "IA" (Intel Architecture) has been used in a
few places where the x86 and amd64 definitions are shared.
* the CFI reader/summariser in readdwarf.c has been expanded &
generalised appropriately.
* the DiCfSI evaluator in debuginfo.c, VG_(use_CFI_info), has
also been generalised appropriately.
The main change is that instead of passing around triples
of (IP, SP, BP) values, a new structure 'D3UnwindRegs' is
passed around instead. This is defined differently for IA and
ARM and succeeds in hiding at least some of the differences
where we don't care about them.
Note also, D3UnwindRegs duplicates, in purpose and structure,
structure 'RegSummary' in priv_d3basics.h. This will be tidied
up in due course.
This commit almost certainly breaks stack unwinding on amd64-linux.
git-svn-id: svn://svn.valgrind.org/valgrind/trunk@10986
