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2015-09-01Don't use bare lstat.Peter Seebach1-4/+5
lstat can fail on XFS if the inode number won't fit in a 32-bit value. Use base_lstat. Also, just in case, don't call it if it's not initialized yet (which should never happen). Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
2015-08-21New option: Use extended attributes to store db values.Peter Seebach1-0/+18
This is a moderately experimental feature which stores values in an extended attribute called 'user.pseudo_data' instead of in the database. Still missing: Database<->filesystem synchronization for this. For at least some workloads, this can dramatically improve performance. Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
2015-08-20Initial profiling implementation.Peter Seebach1-0/+16
A partially-implemented profiler for client time, which basically just inserts (optional) gettimeofday calls in various places and stashes data in a flat file containing one data block per pid. Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
2014-04-21Initial draft xattr supportPeter Seebach1-4/+6
Initial, incomplete, support for extended attributes. Extended attributes are implemented fairly naively, using a second table in the file database using the primary file table's id as a foreign key. The ON DELETE CASCADE behavior requires sqlite 3.6.19 or later with foreign key and trigger support compiled in. To reduce round-trips, the client does not check for existing attributes, but rather, sends three distinct set messages; OP_SET_XATTR, OP_CREATE_XATTR, OP_REPLACE_XATTR. A SET message always succeeds, a CREATE fails if the attribute already exists, and a REPLACE fails if the attribute does not already exist. The /* flags */ feature of makewrappers is used to correct path names appropriately, so all functions are already working with complete paths, and can always use functions that work on links; if they were supposed to dereference, the path fixup code got that. The xattr support is enabled, for now, conditional on whether getfattr --help succeeds. Not yet implemented: Translation for system.posix_acl_access, which is used by "cp -a" (or "cp --preserve-all") on some systems to try to copy modes. Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
2012-08-02Remove the _plain thing, use PSEUDO_STATBUF everywhere.Peter Seebach1-2/+2
The _plain thing was added because of clashes between Linux ("struct stat64 for 64-bit file sizes") and Darwin ("struct stat is already 64 bits"). But it turns out not to be enough, because stat will *fail* if it cannot represent a file size, so when something like unlinkat() calls a non-64-bit stat in order to determine whether a file exists, it gets the wrong answer if the file is over 2GB in size. Solution: Continue using PSEUDO_STATBUF, and also provide defines for base_stat() which can be either real_stat() or real_stat64(), etcetera. This eliminates any reason to need the _plain functions. It also suggests that the other real___fxstatat() calls should someday go away because that is an ugly, ugly, implementation detail. As part of testing this, fix up some bitrot which affected Darwin (such as the continue outside of a loop, but inside an #ifdef; that was left over from the conversion of init_one_wrapper to a separate function).
2011-07-19Fix uninitalized variable.Peter Seebach1-1/+2
You might be wondering why this wasn't caught. Answer: gcc's too smart. Consider: int x; if (condition) x = 23; return x; This function will just return 23. Since gcc knows that it doesn't matter what happens if x is used uninitialized (it's an indeterminate value, thus a possible trap representation, thus undefined behavior to use it), it simplifies the initial part of this away. Thus there's no use of an uninitialized value. Something similar seems to be at issue with the use of the uninitialized f in pseudo_init_one_wrapper. The variable wasn't initialized in the pre-realpath-fix version either, but in that version, the assignment from dlsym was completely unconditional.
2011-06-09Fix realpath(name, NULL) when PSEUDO_DISABLED=1Peter Seebach1-23/+37
On some Linux systems, dlsym("realpath", RTLD_NEXT) prefers for reasons of its own to give a symbol that is also known as old_realpath, which fails and yields EINVAL when called with a null pointer as the second argument. This can be avoided, on some systems, by using dlvsym() to request the GLIBC_2.3 version of the symbol. The wrapper logic is enhanced to allow for specifying versions, although this currently only works for Linux (Darwin has no dlvsym, apparently?). The test case is a trivial program which calls realpath(name, NULL) run with PSEUDO_DISABLED=1.
2011-06-02Add system() wrapper to force setup of the pseudo environment. NotePeter Seebach1-0/+1
that we add an extra fork() so we can do the setup in a child process, but still just pass the command string to the standard system() call.
2011-03-25Merge in ports workPeter Seebach1-430/+34
This is a spiffied-up rebase of a bunch of intermediate changes, presented as a whole because it is, surprisingly, less confusing that way. The basic idea is to separate the guts code into categories ranging from generic stuff that can be the same everywhere and specific variants. The big scary one is the Darwin support, which actually seems to run okay on 64-bit OS X 10.6. (No other variants were tested.) The other example given is support for the old clone() syscall on RHEL 4, which affects some wrlinux use cases. There's a few minor cleanup bits here, such as a function with inconsistent calling conventions, but nothing really exciting.
2010-12-16Restructure wrapfuncs.cMark Hatle1-172/+150
Restructure wrapfuncs.c in an attempt to improve PSEUDO_DISABLED=1 performance. Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
2010-12-13Further amend the system to enable/disable sudo during fork/exec.Mark Hatle1-127/+234
2010-12-09: * (mhatle) Add doc/program_flow to attempt to explain startup/running * (mhatle) guts/* minor cleanup * (mhatle) Reorganize into a new constructor for libpseudo ONLY pseudo main() now manually calls the util init new / revised init for client, wrappers and utils * (mhatle) Add central "reinit" function * (mhatle) Add manul execv* functions * (mhatle) rename pseudo_populate_wrappers to pseudo_check_wrappers Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
2010-12-132010-12-08:Mark Hatle1-60/+12
* (mhatle) Add guts/clone.c to cleanup the clone support * (mhatle) guts/clone.c only run setupenv and reinit when NOT PSEUDO_RELOADED * (mhatle) guts/execve.c whitespace fixe * (mhatle) guts/fork.c similar to guts/clone.c change * (mhatle) pseudo_client.c add reinit function * (mhatle) pseudo_client.c revise client reset, include code from pseudo_wrappers.c * (mhatle) pseudo_server.c move the pid writing to the parent * (mhatle) pseudo_wrappers.c clone cleanup and populate cleanup Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
2010-12-07This is a merge of several commits from a tree which turned out toPeter Seebach1-0/+350
be out of sync in a very inconvenient way. Changes include: * Some whitespace fixes, also move the pseudo_variables definition into pseudo_util.c since it's not used anywhere else. * Further improvements in the fork() support: We now recognize both positive and negative forms of PSEUDO_DISABLED, so we can distinguish between "it was removed from the environment by env -i" (restore the old value) and "it was intentionally turned off" (the new value wins). * clone(2) support. This is a little primitive, and programs might still fail horribly due to clone's semantics, but at least it's there and passes easy test cases. Plus a big patch from Mark Hatle: Cleanup fork/clone and PSEUDO_DISABLED guts/fork.c: * cleanup function and make it more robust * be sure to call pseudo_setupenv prior to pseudo_client_reset to match exec behavior pseudo_wrappers.c: * fix mismatched type in execl_to_v call via typecast * Simplify fork call via single call to wrap_fork() * be sure to save pseudo_disabled * be sure to call pseudo_setupenv prior to pseudo_client_reset to match exec behavior tests: * Add a test of whether pseudo can be disabled/enabled on a fork. Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
2010-10-11Major change: Replace the shell-based makewrappers with a PythonPeter Seebach1-2/+22
one. There's a long story here, but to abbreviate it: The shell script was annoying at best to maintain and starting to show signs of not really being the right tool for the job. For various reasons, we have some other Python stuff in our build system, so we picked Python as the language we were already using for other stuff. We think this works with anything reasonably recent (around Python 2.4 through 2.6). There's a little bit of cleanup, also, of the wrapper templates.
2010-08-25Initial attempt at fixing problems with SIGCHLD being blockedseebs1-0/+1
in processes started under pseudo.
2010-08-11Enable local variable cacheMark Hatle1-7/+14
Add local variable cache via get_value and set_value. The local cache is setup at constructor time (or soon after). Rewrite the pseudo_setupenv and pseudo_dropenv routines, add a new pseudo_setupenvp and pseudo_dropenvp as well to handle the execve cases. We can now successfully use /usr/bin/env -i env and get pseudo values back!
2010-08-04Add new environment values to allow easy override of default locationsMark Hatle1-4/+20
Add PSEUDO_BINDIR, PSEUDO_LIBDIR, and PSEUDO_LOCALSTATEDIR to allow for more easy customization of PSEUDO components at run-time. If these are not set they will be automatically generated based on the existing PSEUDO_PREFIX path. PSEUDO_BINDIR = PSEUDO_PREFIX /bin PSEUDO_LIBDIR = PSEUDO_PREFIX /lib PSEUDO_LOCALSTATEDIR = PSEUDO_PREFIX /var/pseudo Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
2010-06-02Provide a hook to disable symlink "fixing".Peter Seebach1-0/+22
In fakechroot, which pseudo tries to match the functionality of, the default behavior when creating a symlink with an absolute target is to prepend the chroot path, so that underlying syscalls will get the right file. It is necessary to be able to disable this behavior to create target filesystems in some cases. To that end, support a new environment variable, PSEUDO_NOSYMLINKEXP, which disables that behavior.
2010-04-30Improve PSEUDO_DEBUG_FILE.Peter Seebach1-24/+3
The PSEUDO_DEBUG_FILE feature is enhanced, and is now also used by the pseudo server.
2010-04-26Allow specification of debug output file.Peter Seebach1-0/+24
This includes allowing %s (program name) and %d (pid).
2010-04-26Avoid signalling during mutex operations.Peter Seebach1-0/+1
remake(1) can try to close a file from a signal handler. Since any entrance to a pseudo-emulated function requires the mutex, this can result in a deadlock. Solution: Suspend SIGCHLD (and a couple of other signals likely to result in filesystem operations) for the duration of the lock.
2010-04-05Make glob work.Peter Seebach1-0/+28
Moved readlink fixup into a general-purpose function for removing chroot prefixes.
2010-04-05Shuffle some code around.Peter Seebach1-0/+150
Migrate the stable part of the wrapper code (not machine-generated) out of makewrappers, to make it easier to maintain.