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* Fix third argument to setresgid call while setting $(.Leon Timmermans2011-10-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | [Committer's note: discussion on perl5-security-report concluded that exploitability was low to nonexistent because any system that has setresgid but not setregid will pretend to have the latter and define it in terms of the former (see "#ifndef HAS_SETREGID" in perl.h). But the bug should be fixed in case that code gets exposed in the future. The approach taken in perl.h was also called into question and may elicit further discussion and patching.] Note: bug this only affects systems that have setresgid but not setregid (since that codepath prefers the latter over the former). To the best of my knowledge, no such systems exists (nor would it make much sense) so this bug is probably not exploitable, but I can't guarantee that. When the effective group is set using setresgid, it does this: setresgid((Gid_t)PL_gid, (Gid_t)-1, (Gid_t) 1); That last 1 should have been a -1. Instead of leaving the saved GID unchanged it sets it to to 1. This means privileges are not permanently dropped, but instead the GID is set to 1 (if possible). The program can thereafter change it's effective and real GIDs to 1.
* Reimplement $[ as a moduleFather Chrysostomos2011-10-211-4/+0
| | | | | | | | | | | | | | | | | This commit reimplements $[ using PL_check hooks, custom pp func- tions and ties. Outside of its compile-time use, $[ is now parsed as a simple varia- ble, so function calls like foo($[) are permitted, which was not the case with the former implementation removed by e1dccc0. I consider that a bug fix. The ‘That use of $[ is unsupported’ errors are out of necessity deferred to run-time and implemented by a tied $[. Indices between 0 and the array base are now treated consistently, as are indices between a negative array base and zero. That, too, is a bug fix.
* whichsig nul-cleanup.Brian Fraser2011-10-061-15/+42
| | | | | This adds _pv, _pvn, and _pv versions of whichsig() in mg.c, which get both kill "NAME" and %SIG lookup nul-clean.
* Remove if(isGV_with_GP(PL_defoutgv)) checks from mg.cFather Chrysostomos2011-09-121-24/+12
| | | | | | | | | | | | | | | Commit 099be4f1d added code to cope with this: my $x = *STDERR; select($x); $x = 1; which would cause PL_defoutgv to hold something other than a GV, resulting in various crashes. Commit 2acc3314 changed the way rv2gv works on fake globs, and inad- vertently fixed this problem, too, so PL_defoutgv can no longer end up holding something other than a GV. So the code that checks if(isGV_with_GP(PL_defoutgv)) can go.
* remove index offsetting ($[)Zefram2011-09-091-6/+7
| | | | | | $[ remains as a variable. It no longer has compile-time magic. At runtime, it always reads as zero, accepts a write of zero, but dies on writing any other value.
* make assign to $^A update FmLINESDavid Mitchell2011-07-201-0/+8
| | | | | | | | | | | | | | | Currently assigning to $^A updates the string in PL_bodytarget, but doesn't update FmLINES(PL_bodytarget). This can cause later writes to get confused about how many lines have been output, and was causing write.t to fail test 418 under miniperl. (Only under miniperl, because skipping some tests under miniperl affected how $^A's content and line count got messed up). Fix this by updating FmLINES(PL_bodytarget) when $^A is set. (Also fixes a TODO test which was failing due to 'local $^A' in earlier tests)
* Clean up magic_methcall docsFather Chrysostomos2011-07-161-7/+14
| | | | | | | | | | | | | | | | | | | | | | | This is rather unsightly, don’t you think? magic_methcall Invoke a magic method (like FETCH). * sv and mg are the tied thingy and the tie magic; * meth is the name of the method to call; * argc is the number of args (in addition to $self) to pass to the method; the args themselves are any values following the argc argument. * flags: G_DISCARD: invoke method with G_DISCARD flag and don’t return a value G_UNDEF_FILL: fill the stack with argc pointers to PL_sv_undef. Returns the SV (if any) returned by the method, or NULL on failure. (That’s the ‘rendered’ nroff output.) I would have used =over/=item/=back, but autodoc.pl doesn’t seem to like those.
* Split out study magic from pos magic.Nicholas Clark2011-07-011-2/+4
| | | | | | study uses magic to call SvSCREAM_off() if the scalar is modified. Allocate it its own magic type ('G' for now - pos magic is 'g'). Share the same "set" routine and vtable as regexp/bm/fm (setregxp and vtbl_regexp).
* Revert "pos in lvalue context now returns a PVMG instead of a PVLV."Father Chrysostomos2011-06-161-2/+4
| | | | | | | | | This reverts commit 571f0e8653a532c34edde36e797ecba446978b1c. I’m afraid I have to revert this, as it does not modify sv_reftype accordingly, and doing so would add *more* complexity (the opposite of what that commit was trying to achieve) and slow down ref() at run time, by making it search for pos magic.
* pos in lvalue context now returns a PVMG instead of a PVLV.Nicholas Clark2011-06-141-4/+2
| | | | | Store the target SV in mg_obj, instead of LvTARG(). This slightly reduces both code complexity and runtime memory use.
* Make $$ writable, but still magicalFather Chrysostomos2011-06-131-1/+18
| | | | | | | | | | | | | | | | This commit makes $$ writable again, as it was in 5.6, while preserv- ing the magical pid-fetching added recently (post-5.14.0) by com- mit 0e219455. It does this by following Aristotle Pagaltzis’ brilliant suggestion in <20110609145148.GD8471@klangraum.plasmasturm.org>; namely, to store the PID in magic when $$ is written to, so that get-magic can detect whether a fork() has occurred and reset $$ accordingly. This makes it seem as though the fork() code sets $$ itself (which it used to before 0e219455), while even working when C code outside of perl’s control calls fork(). This restores compatibility with DBIx::Connector and PPerl.
* Store a flag for container/value magic in PL_magic_data.Nicholas Clark2011-06-111-38/+3
| | | | Use this to replace S_is_container_magic() in mg.c with a direct lookup.
* Stop localised ties from becoming ro when COWFather Chrysostomos2011-06-041-1/+1
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* Turn $$ into a magical readonly variable that always fetches getpid() ↵Max Maischein2011-05-221-0/+4
| | | | | | | | | | | instead of caching it The intent is that by not caching $$, we eliminate one opportunity for bugs: If one embeds Perl or uses XS and calls fork(3) from C, Perls notion of $$ may go out of sync with what getpid() returns. By always fetching the value of $$ via getpid(), this bug opportunity is eliminated. The overhead of always fetching $$ should be small and is likely only used for tempfile creation, which should be dwarfed by file system accesses.
* Remove PERL_UNUSED_ARG() from Perl_magic_clearsig(), missed by 179c85a2d774d3beNicholas Clark2011-05-191-1/+0
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* Clean: Actually use HvUSEDKEYS() instead of HvKEYS()Michael Witten2011-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This: commit 8aacddc1ea3837f8f1a911d90c644451fc7cfc86 Author: Nick Ing-Simmons <nik@tiuk.ti.com> Date: Tue Dec 18 15:55:22 2001 +0000 Tidied version of Jeffrey Friedl's <jfriedl@yahoo.com> restricted hashes - added delete of READONLY value inhibit & test for same - re-tabbed p4raw-id: //depot/perlio@13760 essentially deprecated HvKEYS() in favor of HvUSEDKEYS(); this is explained in line 144 (now 313) of file `hv.h': /* * HvKEYS gets the number of keys that actually exist(), and is provided * for backwards compatibility with old XS code. The core uses HvUSEDKEYS * (keys, excluding placeholdes) and HvTOTALKEYS (including placeholders) */ This commit simply puts that into practice, and is equivalent to running the following (at least with a35ef416833511da752c4b5b836b7a8915712aab checked out): git grep -l HvKEYS | sed /hv.h/d | xargs sed -i s/HvKEYS/HvUSEDKEYS/ Notice that HvKEYS is currently just an alias for HvUSEDKEYS: $ git show a35ef416833511da752c4b5b836b7a8915712aab:hv.h | sed -n 318p #define HvKEYS(hv) HvUSEDKEYS(hv) According to `make tests': All tests successful.
* S_mg_findext_flags wasn't declared staticGisle Aas2011-05-181-1/+1
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* Store the compiled format in mg_ptr instead of after SvCUR() - fixes RT #89218Nicholas Clark2011-05-181-1/+0
| | | | | | | | | | | | | | | | | | | | | Formats are compiled down to a sequence of U32 opcodes in doparseform(). Previously the block of opcodes was stored in the buffer of SvPVX() after the raw string by extending the buffer, and calculating the first U32 aligned address after SvCUR(). A flag bit on the scalar was set to signal this hackery, tested with SvCOMPILED() The flag bit used happened to be the same as one of the two used by to signal Boyer-Moore compiled scalars. The assumption was that no scalar can be used for both. Unfortunately, this isn't quite true. Given that the scalar is alway upgraded to PVMG to add PERL_MAGIC_fm magic, to clear the cached compiled version, there's no extra memory cost in using mg_ptr in the MAGIC struct to point directly to the block of U32 opcodes. The test for "is there a compiled version" can switch to mg_find(..., PERL_MAGIC_fm) returning a pointer, and the use of a flag bit abolished. Retain SvCOMPILED() and SvCOMPILED_{on,off}() as compatibility for XS code on CPAN - the first is always 0, the other two now no-ops.
* make mg_clear() et al behave when RC==0David Mitchell2011-04-071-16/+30
| | | | | | | | | | | | | | | | | | | | | | | | | The functions S_save_magic() and S_restore_magic(), which are called by mg_get(), mg_set(), mg_length(), mg_size() and mg_clear(), are not robust when called with an SV whose reference count is zero. Basically, one of the actions of S_save_magic() is to temporarily increase the refcount of the SV, and then for S_restore_magic() to reduce it again at the end, so that if any of the magic functions called inbetween decrease the count, it won't be prematurely freed. However, if the count starts at zero, then bumping it up and bringing it back down to zero, triggers a spurious second freeing. So, if its zero, just skip the whole bumping thing. Now, we shouldn't really be calling these functions will a zero-refcount SV, but these things happen, and its best to be robust. In particular, this fixes RT #87860, which was ultimately triggered by a bug in Set::Object 1.28 that managed to create an HV with null SvMAGIC field, but with the RMG flag set. When freeing that HV, sv_clear() skips doing mg_free() because SvMAGIC is null, whereas later it calls Perl_hv_undef_flags, which calls mg_clear() because it uses the test SvRMAGICAL(hv) (which is true).
* #84774: local $_ calls STORE when $_ is aliased to a tied hash elementJan Dubois2011-03-201-1/+4
| | | | | | local($_) will now strip all magic from $_, so that it is always safe to localize $_, regardless what kind of special (or tied) variable it may have been aliased to.
* Perl_sighandler: only inc SS_ix for unsafe signalsDavid Mitchell2011-03-191-9/+13
| | | | | | | | | Perl_sighandler currently increments the savestack by 5 before running a signal handler, to avoid messing with a partially completed SS push operation that's been interrupted. This is irrelevant for safe signals, so make this action conditional on unsafe signals only.
* In signal handler, don't inc stack pointersDavid Mitchell2011-03-191-14/+1
| | | | | | | | | | | | | | | | | | | | | | | | In Perl_sighandler, we currently increment PL_markstack_ptr and PL_scopestack_ix. This was added back in 1997 in the era of unsafe signals, to make them slightly less unsafe. The idea presumably was to stop signal handlers inadvertently corrupting the top element of each stack. However, given that the normal method of pushing something onto those stacks is to increment the pointer before pushing the value, I don't see how that can happen. The downside of this is that an uninitialised or stale value can be left in the 'hole' left on these stacks. When exiting from a signal handler via exit(), these holes can be read and corruption occur, while stack unwinding is taking place. The ordering of things means we can't use SAVEDESTRUCTOR_X to undo the damage. This commit leaves the 'PL_savestack_ix += 5', because in this case, with unsafe signals, it *is* possible to interrupt halfway through a new set of save data being pushed onto the stack, and it *is* possible for this to be undone via SAVEDESTRUCTOR_X. (But it's still unsafe and half-baked.) This fixes [perl #85206].
* Detect unsafe signals more reliably on BSD/SolarisLeon Timmermans2011-02-241-2/+2
| | | | | | | | | | | | | | | | Previous versions of the Posix spec allowed the struct siginfo_t* parameter passed to the signal handler to be NULL in certain cases. More recent Posix specifications (SUSv3) have rescinded this: Now this parameter is required always to be non-NULL. However we use this parameter to differentiate between safe and unsafe signals, as in the former it will always be NULL and in the latter case it should have been non-NULL. This patch fixes this issue by also relying on the ucontext_t* parameter. This should reliably be non-NULL when using unsafe signals handlers. Signed-off-by: Chris 'BinGOs' Williams <chris@bingosnet.co.uk>
* No sip without SA_SIGINFO. Broken in c22d665.Craig A. Berry2011-02-171-1/+1
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* Unblock signal-mask on error for unsafe signalsLeon Timmermans2011-02-171-2/+14
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* multifile patch against blead/pod/*.podTom Christiansen2011-02-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | I mostly fixed spelling mistakes, some of very long standing, but a few files got more attentive word-smithying. I've updated: pod/perl.pod pod/perldelta.pod pod/perl592delta.pod pod/perl5120delta.pod pod/perl51310delta.pod pod/perl5139delta.pod pod/perlfunc.pod pod/perlop.pod pod/perlrebackslash.pod pod/perlrecharclass.pod pod/perlutil.pod pod/perlhack.pod pod/perlintern.pod pod/perlnetware.pod pod/perlpolicy.pod
* Also unblock signal handlers throwing an exceptionLeon Timmermans2011-01-181-12/+19
| | | | | Also handle and test the edge case of a signal handler throwing an exception
* Conditionally unblock after signal handler[#82040]Leon Timmermans2011-01-171-3/+20
| | | | | Only unblock signal after a safe-signal handler is executed if that signal was also unblocked before the handler.
* In Perl_write_to_stderr(), use Perl_magic_methcall() if STDERR is tied.Nicholas Clark2011-01-131-0/+11
| | | | | | Add a flag G_WRITING_TO_STDERR to signal that Perl_magic_methcall() needs to localise PL_stderrgv to NULL, and save/free temps, inside its ENTER/LEAVE pair.
* Better handling of magic methods freeing the SVDavid Mitchell2010-12-301-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a fix for RT #81230 (and more). Currently, mg_get() works around the case where the called magic (e.g. FETCH) frees the magic SV. It does this by unconditionally pushing the SV on the tmps stack before invoking the method. There are two issues with this. Firstly, it may artificially extend the life of the SV. This was the root of the problem with #81230. There, the DB_File code, under -T, created a tainted tied object. Accessing the object (within FETCH as it happens), caused mg_get() to be invoked on the object (due to the taint magic), and thus extend the life of the object. This then caused c<untie %h if $h{k}> to give the warning untie attempted while 1 inner references still exist. This only became noticeable after efaf36747029c85b4d8825318cb4d485a0bb350e, which stopped wrapping magic method calls in SAVETMPS/FREETMPS. The second issue issue that this protection only applies to mg_get(); functions like mg_set() can still segfault if the SV is deleted. This commit fixes both problems as follows: First, the protection mechanism is moved out of mg_get() and into save_magic() / restore_magic(), so that it protects more things. Secondly, the protection is now: * in save_magic(), SvREFCNT_inc() the SV, thus protecting it from being freed during FETCH (or whatever) * in restore_magic(), SvREFCNT_dec() the SV, undoing the protection without extending the life of the SV, *except* if the refcount is 1 (ie FETCH tried to free it), then push it on the mortals stack to extend it life a bit so our callers wont choke on it.
* Remove lots of unused, VMS-specific variables.Craig A. Berry2010-12-021-1/+0
| | | | Brought to you by -Duser_c_flags=/WARN=(ENABLE=LEVEL5,INFORMATIONAL=ALL)
* Add mg_findextFlorian Ragwitz2010-11-301-9/+36
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* Implement $^A taintingNiko Tyni2010-11-141-0/+10
| | | | | | | | | The format accumulator $^A now becomes tainted when formline() is called with tainted data. There is still one failing test from the TODO set; it seems that the $^A get magic is handled too late for the taintedness to show up.
* Eliminate PL_dirtyFlorian Ragwitz2010-11-141-1/+1
| | | | | It now only exists as a compatibility macro for extensions that want to introspect it.
* Add ${^GLOBAL_PHASE}Florian Ragwitz2010-11-141-1/+7
| | | | This exposes the current top-level interpreter phase to perl space.
* [perl #77238] Aliased @ISA does not workFather Chrysostomos2010-11-131-11/+17
| | | | | This makes aliased @ISA arrays work by storing a non-magical AV as the mg_obj if there need to be multiple entries.
* tidy code in Perl_sighandler()David Mitchell2010-11-011-14/+13
| | | | | | | | | | | | | | | | | | | 1) compress if (...) flag |= 1 ... if (flag & 1) { ... into if (...) { flag |= 1 .... 2) re-order the flag bits, since over the years some bits have become redundant.
* RT #76248: double-freed SV with nested sig-handlerDavid Mitchell2010-11-011-22/+21
| | | | | | | | | | | | | | | | | | | There was some buggy code in Perl_sighandler() related to getting an SV with the signal name to pass to the perl-level handler function. ` Basically: on threaded builds, a sig handler that died leaked PL_psig_name[sig]; on unthreaded builds, in a recursive handler that died, PL_sig_sv was prematurely freed. PL_sig_sv was originally just a file static var that was not recursion-save anyway, and got promoted to perlvars.h when it should instead have been done away with. So I've got rid of it now, and rationalised the code, which fixed the two issues listed above. Also added an assert which makes the dodgy manual popping of the save stack slightly less dodgy.
* Switch the core MRO code over to HvENAMEFather Chrysostomos2010-10-291-1/+3
| | | | | | | | | | | | | | | | | | | | | | This has the side-effect of fixing these one-liners: $ perl5.13.5 -le' my $glob = \*foo::ISA; delete $::{"foo::"}; *$glob = *a' Bus error $ perl5.13.5 -le' my $glob = \*foo::ISA; delete $::{"foo::"}; *$glob = []' Bus error $ perl5.13.6 -le'sub baz; my $glob = \*foo::bar; delete $::{"foo::"}; *$glob = *baz;' Bus error $ perl5.13.6 -le'sub foo::bar; my $glob = \*foo::bar; delete $::{"foo::"}; *$glob = *baz;' Bus error In the first two cases the crash was inadvertently fixed (isn’t it nice when that happens?) in 5.13.6 (by 6f86b615fa7), but there was still a fatal error: Can't call mro_isa_changed_in() on anonymous symbol table at -e line 1. Because sv_clear calls ->DESTROY, if an object’s stash has been detached from the symbol table, mro_get_linear_isa can be called on a hash with no HvENAME. So HvNAME is used as a fallback for those cases.
* full API for cop hint hashesZefram2010-10-211-15/+9
| | | | | | | | | | | | | Expose cop hint hashes as a type COPHH, with a cophh_* API which is a macro layer over the refcounted_he_* API. The documentation for cophh_* describes purely API-visible behaviour, whereas the refcounted_he_* documentation describes the functions mainly in terms of the implementation. Revise the cop_hints_* API, using the flags parameter consistently and reimplementing in terms of cophh_*. Use the cophh_* and cop_hints_* functions consistently where appropriate. [Modified by the committer to update two calls to Perl_refcounted_he_fetch recently added to newPMOP.]
* plugin mechanism to rewrite calls to a subroutineZefram2010-10-101-12/+53
| | | | | | | | | | | | | | | | | | | | | | | | New magic type PERL_MAGIC_checkcall attaches a function to a CV, which will be called as the second half of the op checker for an entersub op calling that CV. Default state, in the absence of this magic, is to process the CV's prototype if it has one, or apply list context to all the arguments if not. New API functions cv_get_call_checker() and cv_set_call_checker() provide a clean interface to this facility, hiding the internal use of magic. Expose in the API the new functions rv2cv_op_cv(), ck_entersub_args_list(), ck_entersub_args_proto(), and ck_entersub_args_proto_or_list(), which are meaningful segments of standard entersub op checking and are likely to be useful in plugged-in call checker functions. Expose new API function op_contextualize(), which is a public interface to the internal scalar()/list()/scalarvoid() functions. This API is likely to be required in most plugged-in call checker functions. Incidentally add new function mg_free_type(), in the API, which will remove magic of one type from an SV. (mg_free() removes all magic, and there isn't anything else more selective.)
* Add two missing break in Perl_magic_set's big switchVincent Pit2010-08-311-1/+2
| | | | | This fixes $^A being reset when $1..$2 are localized before any regexp match happened.
* Remove CALL_FPTR and CPERLscope.Ben Morrow2010-08-201-8/+8
| | | | | | | | | | | | | | | | These are left from PERL_OBJECT, which was an implementation of multiplicity using C++ objects. PERL_OBJECT was removed in 5.8, but the macros seem to have been cargo-culted all over the core (including in places where they would have been inappropriate originally). Since they now do exactly nothing, it's cleaner to remove them. I have left the definitions in perl.h, under #ifndef PERL_CORE, since some CPAN XS code uses them (also often incorrectly). I have also left STATIC alone, since it seems potentially more useful and is much more ingrained. The only appearance of these macros this patch doesn't touch is in Devel-PPPort, because that's a CPAN module.
* RT #74436: [PATCH] Add -Wwrite-stringsRobin Barker2010-08-141-1/+1
| | | | | | The perl source has for some while been clean to -Wwrite-strings. I suggest this warning be added to cflags. The patch makes the appropriate change to cflags.SH and silences a warning from mg.c
* optimise single backreferencesDavid Mitchell2010-08-011-1/+2
| | | | | | | | | | | Rather than creating an AV and pushing the backref onto it, store a single backref directly in the mg_obj or xhv_backreferences slot. If the backref is an AV, then we skip this optimisation (although I don't think at the moment, that an AV would ever be pointed to by some backref magic). So the test of whether the optimisation is is in effect is whether the thing in the slot is an AV or not.
* Restore errno if signal handler changes itLubomir Rintel2010-07-261-0/+2
| | | | | It's way too easy to forget to "local $!" in signal handlers and changing $! when signal hits between two ops is probably never useful.
* Add Perl_croak_no_modify() to implement Perl_croak("%s", PL_no_modify).Nicholas Clark2010-06-271-2/+2
| | | | | This reduces object code size, reducing CPU cache pressure on the non-exception paths.
* Revert "make 'local $tied' untied"David Mitchell2010-06-071-1/+0
| | | | | | | | | This reverts commit 191ad7eff570fc96c93993e4358f83e2033365d6. Some modules (e.g. File::chdir) relied on the current behaviour of local $tied_scalar, so lets leave things as-is for now. See http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2010-05/msg00627.html
* update Perl_magic_methcall descriptionDavid Mitchell2010-06-051-4/+3
| | | | it's now a varargs function
* rename DM_ARRAY flag to DM_ARRAY_ISADavid Mitchell2010-06-041-1/+1
| | | | | This better represents its current role as specifically delaying magic on @ISA as opposed to a general array magic delay mechanism.
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