| Message ID | 20190219012913.GB29070@altlinux.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] libio: do not unbuffer legacy standard files in compatibility mode [BZ #24228] | expand |
* Dmitry V. Levin: > Commit glibc-2.23~693 (a601b74d31ca086de38441d316a3dee24c866305) Please quote the commit hash and commit subject, kernel-style. (How did you determine this reference, anyway?) > diff --git a/libio/genops.c b/libio/genops.c > index 2a0d9b81df..aa92d61b6b 100644 > --- a/libio/genops.c > +++ b/libio/genops.c > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > { > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > + continue; > +#endif I wonder if we should check _IO_legacy_file only here. This is related to the previous discussion. > diff --git a/libio/tst-bz24228.c b/libio/tst-bz24228.c > new file mode 100644 > index 0000000000..3692f14b71 > --- /dev/null > +++ b/libio/tst-bz24228.c > @@ -0,0 +1,30 @@ > +/* BZ #24228 check for memory corruption in legacy libio > + > + Copyright (C) 2019 Free Software Foundation, Inc. > + This file is part of the GNU C Library. We do not generally have a blank line for the “Copyright” line, I think. > +#include <mcheck.h> > +#include <support/test-driver.h> > + > +static int > +do_test (void) > +{ > + mtrace (); > + return 0; > +} > + > +#include <support/test-driver.c> > diff --git a/libio/tst-bz24228.map b/libio/tst-bz24228.map > new file mode 100644 > index 0000000000..ecb8c058f5 > --- /dev/null > +++ b/libio/tst-bz24228.map > @@ -0,0 +1,3 @@ > +{ > + local: _IO_stdin_used; > +}; Please add a comment to the file why you are doing this, something like “hide the symbol from libc.so.6 to switch to the libio/oldfileops.c implementation (if it is available for the architecture)”. Thanks, Florian
On Wed, Mar 13, 2019 at 04:08:16PM +0100, Florian Weimer wrote: > * Dmitry V. Levin: > > > Commit glibc-2.23~693 (a601b74d31ca086de38441d316a3dee24c866305) > > Please quote the commit hash and commit subject, kernel-style. The kernel-style reference would look this way: Commit a601b74d31ca ("In preparation for fixing BZ#16734, fix failure in misc/tst-error1-mem when _G_HAVE_MMAP is turned off.") I'd like to add a reference to glibc-2.23~693 somewhere because I find it useful, but I don't see any suitable place for it in this long kernel-style form. > (How did you determine this reference, anyway?) Sorry? > > diff --git a/libio/genops.c b/libio/genops.c > > index 2a0d9b81df..aa92d61b6b 100644 > > --- a/libio/genops.c > > +++ b/libio/genops.c > > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > > { > > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > > + continue; > > +#endif > > I wonder if we should check _IO_legacy_file only here. This is related > to the previous discussion. If we omitted the check for _IO_stdin_used, then standard files would be skipped and misc/tst-error1-mem would complain. > > diff --git a/libio/tst-bz24228.c b/libio/tst-bz24228.c > > new file mode 100644 > > index 0000000000..3692f14b71 > > --- /dev/null > > +++ b/libio/tst-bz24228.c > > @@ -0,0 +1,30 @@ > > +/* BZ #24228 check for memory corruption in legacy libio > > + > > + Copyright (C) 2019 Free Software Foundation, Inc. > > + This file is part of the GNU C Library. > > We do not generally have a blank line for the “Copyright” line, I think. No problem, I can remove it. I don't think we are quite consistent about it, though. > > +#include <mcheck.h> > > +#include <support/test-driver.h> > > + > > +static int > > +do_test (void) > > +{ > > + mtrace (); > > + return 0; > > +} > > + > > +#include <support/test-driver.c> > > diff --git a/libio/tst-bz24228.map b/libio/tst-bz24228.map > > new file mode 100644 > > index 0000000000..ecb8c058f5 > > --- /dev/null > > +++ b/libio/tst-bz24228.map > > @@ -0,0 +1,3 @@ > > +{ > > + local: _IO_stdin_used; > > +}; > > Please add a comment to the file why you are doing this, something like > “hide the symbol from libc.so.6 to switch to the libio/oldfileops.c > implementation (if it is available for the architecture)”. Indeed, thanks for the suggestion.
* Dmitry V. Levin: > On Wed, Mar 13, 2019 at 04:08:16PM +0100, Florian Weimer wrote: >> * Dmitry V. Levin: >> >> > Commit glibc-2.23~693 (a601b74d31ca086de38441d316a3dee24c866305) >> >> Please quote the commit hash and commit subject, kernel-style. > > The kernel-style reference would look this way: > > Commit a601b74d31ca ("In preparation for fixing BZ#16734, fix failure in > misc/tst-error1-mem when _G_HAVE_MMAP is turned off.") > > I'd like to add a reference to glibc-2.23~693 somewhere because > I find it useful, but I don't see any suitable place for it > in this long kernel-style form. Hmm. It's not strictly speaking unique because we do not reject branches, unfortunately. >> (How did you determine this reference, anyway?) > > Sorry? glibc-2.23~693 looks nice, but I can't get “git describe” to produce. >> > diff --git a/libio/genops.c b/libio/genops.c >> > index 2a0d9b81df..aa92d61b6b 100644 >> > --- a/libio/genops.c >> > +++ b/libio/genops.c >> > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) >> > >> > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) >> > { >> > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) >> > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) >> > + continue; >> > +#endif >> >> I wonder if we should check _IO_legacy_file only here. This is related >> to the previous discussion. > > If we omitted the check for _IO_stdin_used, then standard files > would be skipped and misc/tst-error1-mem would complain. Really? Why would _IO_legacy_file be true for those? That's definitely not what I intended. Thanks, Florian
On Wed, Mar 13, 2019 at 04:49:59PM +0100, Florian Weimer wrote: > * Dmitry V. Levin: > > > On Wed, Mar 13, 2019 at 04:08:16PM +0100, Florian Weimer wrote: > >> * Dmitry V. Levin: > >> > >> > Commit glibc-2.23~693 (a601b74d31ca086de38441d316a3dee24c866305) > >> > >> Please quote the commit hash and commit subject, kernel-style. > > > > The kernel-style reference would look this way: > > > > Commit a601b74d31ca ("In preparation for fixing BZ#16734, fix failure in > > misc/tst-error1-mem when _G_HAVE_MMAP is turned off.") > > > > I'd like to add a reference to glibc-2.23~693 somewhere because > > I find it useful, but I don't see any suitable place for it > > in this long kernel-style form. > > Hmm. It's not strictly speaking unique because we do not reject > branches, unfortunately. No, it's not unique so I also add the commit hash, but it's handy. > >> (How did you determine this reference, anyway?) > > > > Sorry? > > glibc-2.23~693 looks nice, but I can't get “git describe” to produce. git describe --contains a601b74d31ca > >> > diff --git a/libio/genops.c b/libio/genops.c > >> > index 2a0d9b81df..aa92d61b6b 100644 > >> > --- a/libio/genops.c > >> > +++ b/libio/genops.c > >> > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > >> > > >> > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > >> > { > >> > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > >> > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > >> > + continue; > >> > +#endif > >> > >> I wonder if we should check _IO_legacy_file only here. This is related > >> to the previous discussion. > > > > If we omitted the check for _IO_stdin_used, then standard files > > would be skipped and misc/tst-error1-mem would complain. > > Really? Why would _IO_legacy_file be true for those? That's definitely > not what I intended. I don't see why it shouldn't be the case, but it was a month ago when I looked at the code, so I'll re-check.
* Dmitry V. Levin: > diff --git a/libio/genops.c b/libio/genops.c > index 2a0d9b81df..aa92d61b6b 100644 > --- a/libio/genops.c > +++ b/libio/genops.c > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > { > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > + continue; > +#endif > if (! (fp->_flags & _IO_UNBUFFERED) > /* Iff stream is un-orientated, it wasn't used. */ > && fp->_mode != 0) I believe a better fix would be this, in case an old-style file showed up for a different reason: #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) bool potentially_wide_stream = _IO_vtable_offset (fp) != 0; #else bool potentially_wide_stream = true; #endif if (potentially_wide_stream && fp->_mode > 0) _IO_wsetb (fp, NULL, NULL, 0); This is _IO_new_fclose handles this situation. I fear the test is unreliable because it depends on what fp->_mode evaluates to (which is not actually present in the struct with old files). But the test is definitely better than nothing. Thanks, Florian
On Wed, Jun 19, 2019 at 03:10:14PM +0200, Florian Weimer wrote: > * Dmitry V. Levin: > > > diff --git a/libio/genops.c b/libio/genops.c > > index 2a0d9b81df..aa92d61b6b 100644 > > --- a/libio/genops.c > > +++ b/libio/genops.c > > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > > { > > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > > + continue; > > +#endif > > if (! (fp->_flags & _IO_UNBUFFERED) > > /* Iff stream is un-orientated, it wasn't used. */ > > && fp->_mode != 0) > > I believe a better fix would be this, in case an old-style file showed > up for a different reason: > > #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > bool potentially_wide_stream = _IO_vtable_offset (fp) != 0; > #else > bool potentially_wide_stream = true; > #endif > if (potentially_wide_stream && fp->_mode > 0) > _IO_wsetb (fp, NULL, NULL, 0); > > This is _IO_new_fclose handles this situation. Yes, this approach seems to work, too: diff --git a/libio/genops.c b/libio/genops.c index 2a0d9b81df..575f0e6584 100644 --- a/libio/genops.c +++ b/libio/genops.c @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) { +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) + if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) + continue; +#endif if (! (fp->_flags & _IO_UNBUFFERED) /* Iff stream is un-orientated, it wasn't used. */ && fp->_mode != 0) > I fear the test is unreliable because it depends on what fp->_mode > evaluates to (which is not actually present in the struct with old > files). But the test is definitely better than nothing. Sorry, I couldn't think of a more reliable test than that.
* Dmitry V. Levin: > On Wed, Jun 19, 2019 at 03:10:14PM +0200, Florian Weimer wrote: >> * Dmitry V. Levin: >> >> > diff --git a/libio/genops.c b/libio/genops.c >> > index 2a0d9b81df..aa92d61b6b 100644 >> > --- a/libio/genops.c >> > +++ b/libio/genops.c >> > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) >> > >> > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) >> > { >> > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) >> > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) >> > + continue; >> > +#endif >> > if (! (fp->_flags & _IO_UNBUFFERED) >> > /* Iff stream is un-orientated, it wasn't used. */ >> > && fp->_mode != 0) >> >> I believe a better fix would be this, in case an old-style file showed >> up for a different reason: >> >> #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) >> bool potentially_wide_stream = _IO_vtable_offset (fp) != 0; >> #else >> bool potentially_wide_stream = true; >> #endif >> if (potentially_wide_stream && fp->_mode > 0) >> _IO_wsetb (fp, NULL, NULL, 0); >> >> This is _IO_new_fclose handles this situation. > > Yes, this approach seems to work, too: > > diff --git a/libio/genops.c b/libio/genops.c > index 2a0d9b81df..575f0e6584 100644 > --- a/libio/genops.c > +++ b/libio/genops.c > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > { > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > + if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) > + continue; > +#endif > if (! (fp->_flags & _IO_UNBUFFERED) > /* Iff stream is un-orientated, it wasn't used. */ > && fp->_mode != 0) Hmm, right there's an early access to fp->_mode that I had missed. Should we still flush buffers in old binaries? I think we could do this instead: int mode; #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) mode = 1; /* Old streams are never wide. */ else mode = fp->_mode; #else mode = fp->_mode; #endif And then use mode instead of fp->_mode below. Does this make sense? >> I fear the test is unreliable because it depends on what fp->_mode >> evaluates to (which is not actually present in the struct with old >> files). But the test is definitely better than nothing. > > Sorry, I couldn't think of a more reliable test than that. I came up with this (also with the linker script). But curiously enough, the padding is not actually needed. The test is only valid with GLIBC_2.0 targets, it crashes for newer targets which do not define _IO_stdout_. #include <stdio.h> #include <stdlib.h> int pad1[] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }; int _IO_stdout_[20] __attribute__ ((nocommon)); int pad2[] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }; int main (void) { /* Simulate old-style printf. */ fprintf ((FILE *) &_IO_stdout_, "info: testing old printing\n"); return 0; } This could be improved by using internal headers when the test is built within the glibc tree, so that hard-coding the size of _IO_stdout_ is not required. I guess we could add both tests, just in case. Thanks, Florian
On Wed, Jun 19, 2019 at 06:15:06PM +0200, Florian Weimer wrote: > * Dmitry V. Levin: > > On Wed, Jun 19, 2019 at 03:10:14PM +0200, Florian Weimer wrote: > >> * Dmitry V. Levin: > >> > >> > diff --git a/libio/genops.c b/libio/genops.c > >> > index 2a0d9b81df..aa92d61b6b 100644 > >> > --- a/libio/genops.c > >> > +++ b/libio/genops.c > >> > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > >> > > >> > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > >> > { > >> > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > >> > + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) > >> > + continue; > >> > +#endif > >> > if (! (fp->_flags & _IO_UNBUFFERED) > >> > /* Iff stream is un-orientated, it wasn't used. */ > >> > && fp->_mode != 0) > >> > >> I believe a better fix would be this, in case an old-style file showed > >> up for a different reason: > >> > >> #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > >> bool potentially_wide_stream = _IO_vtable_offset (fp) != 0; > >> #else > >> bool potentially_wide_stream = true; > >> #endif > >> if (potentially_wide_stream && fp->_mode > 0) > >> _IO_wsetb (fp, NULL, NULL, 0); > >> > >> This is _IO_new_fclose handles this situation. > > > > Yes, this approach seems to work, too: > > > > diff --git a/libio/genops.c b/libio/genops.c > > index 2a0d9b81df..575f0e6584 100644 > > --- a/libio/genops.c > > +++ b/libio/genops.c > > @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) > > > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > > { > > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > > + if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) > > + continue; > > +#endif > > if (! (fp->_flags & _IO_UNBUFFERED) > > /* Iff stream is un-orientated, it wasn't used. */ > > && fp->_mode != 0) > > Hmm, right there's an early access to fp->_mode that I had missed. > Should we still flush buffers in old binaries? > > I think we could do this instead: > > int mode; > #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) > mode = 1; /* Old streams are never wide. */ > else > mode = fp->_mode; > #else > mode = fp->_mode; > #endif > > And then use mode instead of fp->_mode below. Does this make sense? _mode is not the only member that is not available in legacy libio, _freeres_list and _freeres_buf also should be avoided. Would you prefer the following approach? diff --git a/libio/genops.c b/libio/genops.c index 2a0d9b81df..11a15549e8 100644 --- a/libio/genops.c +++ b/libio/genops.c @@ -789,9 +789,16 @@ _IO_unbuffer_all (void) for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) { + int legacy = 0; + +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) + if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) + legacy = 1; +#endif + if (! (fp->_flags & _IO_UNBUFFERED) /* Iff stream is un-orientated, it wasn't used. */ - && fp->_mode != 0) + && (legacy || fp->_mode != 0)) { #ifdef _IO_MTSAFE_IO int cnt; @@ -805,7 +812,7 @@ _IO_unbuffer_all (void) __sched_yield (); #endif - if (! dealloc_buffers && !(fp->_flags & _IO_USER_BUF)) + if (! legacy && ! dealloc_buffers && !(fp->_flags & _IO_USER_BUF)) { fp->_flags |= _IO_USER_BUF; @@ -816,7 +823,7 @@ _IO_unbuffer_all (void) _IO_SETBUF (fp, NULL, 0); - if (fp->_mode > 0) + if (! legacy && fp->_mode > 0) _IO_wsetb (fp, NULL, NULL, 0); #ifdef _IO_MTSAFE_IO @@ -827,7 +834,8 @@ _IO_unbuffer_all (void) /* Make sure that never again the wide char functions can be used. */ - fp->_mode = -1; + if (! legacy) + fp->_mode = -1; } #ifdef _IO_MTSAFE_IO
* Dmitry V. Levin: > _mode is not the only member that is not available in legacy libio, > _freeres_list and _freeres_buf also should be avoided. > Would you prefer the following approach? > > diff --git a/libio/genops.c b/libio/genops.c > index 2a0d9b81df..11a15549e8 100644 > --- a/libio/genops.c > +++ b/libio/genops.c > @@ -789,9 +789,16 @@ _IO_unbuffer_all (void) > > for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) > { > + int legacy = 0; > + > +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) > + if (__glibc_unlikely (_IO_vtable_offset (fp) != 0)) > + legacy = 1; > +#endif This approach looks reasonable to me. It's certainly much better than what we have today. If you post a full patch, I'll test it against one of the problematic OpenJDK 8 builds.
diff --git a/libio/Makefile b/libio/Makefile index 95b91084dd..d6cabe5ef3 100644 --- a/libio/Makefile +++ b/libio/Makefile @@ -65,7 +65,7 @@ tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc \ tst-setvbuf1 tst-popen1 tst-fgetwc bug-wsetpos tst-fseek \ tst-fwrite-error tst-ftell-partial-wide tst-ftell-active-handler \ tst-ftell-append tst-fputws tst-bz22415 tst-fgetc-after-eof \ - tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051 tst-bz24153 + tst-sprintf-ub tst-sprintf-chk-ub tst-bz24051 tst-bz24153 tst-bz24228 tests-internal = tst-vtables tst-vtables-interposed tst-readline @@ -157,15 +157,19 @@ CFLAGS-tst_putwc.c += -DOBJPFX=\"$(objpfx)\" CFLAGS-tst-sprintf-ub.c += -Wno-restrict CFLAGS-tst-sprintf-chk-ub.c += -Wno-restrict +LDFLAGS-tst-bz24228 = -Wl,--version-script=tst-bz24228.map + tst_wprintf2-ARGS = "Some Text" test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace +tst-bz24228-ENV = MALLOC_TRACE=$(objpfx)tst-bz24228.mtrace generated += test-fmemopen.mtrace test-fmemopen.check generated += tst-fopenloc.mtrace tst-fopenloc.check generated += tst-bz22415.mtrace tst-bz22415.check +generated += tst-bz24228.mtrace tst-bz24228.check aux := fileops genops stdfiles stdio strops @@ -180,7 +184,7 @@ shared-only-routines = oldiofopen oldiofdopen oldiofclose oldfileops \ ifeq ($(run-built-tests),yes) tests-special += $(objpfx)test-freopen.out $(objpfx)test-fmemopen-mem.out \ - $(objpfx)tst-bz22415-mem.out + $(objpfx)tst-bz22415-mem.out $(objpfx)tst-bz24228-mem.out ifeq (yes,$(build-shared)) # Run tst-fopenloc-cmp.out and tst-openloc-mem.out only if shared # library is enabled since they depend on tst-fopenloc.out. @@ -235,3 +239,7 @@ $(objpfx)tst-fopenloc-mem.out: $(objpfx)tst-fopenloc.out $(objpfx)tst-bz22415-mem.out: $(objpfx)tst-bz22415.out $(common-objpfx)malloc/mtrace $(objpfx)tst-bz22415.mtrace > $@; \ $(evaluate-test) + +$(objpfx)tst-bz24228-mem.out: $(objpfx)tst-bz24228.out + $(common-objpfx)malloc/mtrace $(objpfx)tst-bz24228.mtrace > $@; \ + $(evaluate-test) diff --git a/libio/genops.c b/libio/genops.c index 2a0d9b81df..aa92d61b6b 100644 --- a/libio/genops.c +++ b/libio/genops.c @@ -789,6 +789,10 @@ _IO_unbuffer_all (void) for (fp = (FILE *) _IO_list_all; fp; fp = fp->_chain) { +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1) + if (__glibc_unlikely (&_IO_stdin_used == NULL) && _IO_legacy_file (fp)) + continue; +#endif if (! (fp->_flags & _IO_UNBUFFERED) /* Iff stream is un-orientated, it wasn't used. */ && fp->_mode != 0) diff --git a/libio/tst-bz24228.c b/libio/tst-bz24228.c new file mode 100644 index 0000000000..3692f14b71 --- /dev/null +++ b/libio/tst-bz24228.c @@ -0,0 +1,30 @@ +/* BZ #24228 check for memory corruption in legacy libio + + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <mcheck.h> +#include <support/test-driver.h> + +static int +do_test (void) +{ + mtrace (); + return 0; +} + +#include <support/test-driver.c> diff --git a/libio/tst-bz24228.map b/libio/tst-bz24228.map new file mode 100644 index 0000000000..ecb8c058f5 --- /dev/null +++ b/libio/tst-bz24228.map @@ -0,0 +1,3 @@ +{ + local: _IO_stdin_used; +};