From dc30acf20bd635d71cd4c84100e842fdf0429e48 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Wed, 22 Jun 2022 13:16:30 +0200 Subject: debug: make __read_chk a cancellation point (bug 29274) The __read_chk function, as the implementation behind the fortified read function, must be a cancellation point, thus it cannot use INLINE_SYSCALL. --- debug/Makefile | 7 +++++++ debug/read_chk.c | 10 --------- debug/tst-read-chk-cancel.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 57 insertions(+), 10 deletions(-) create mode 100644 debug/tst-read-chk-cancel.c diff --git a/debug/Makefile b/debug/Makefile index 96029f32ee..456b349c4d 100644 --- a/debug/Makefile +++ b/debug/Makefile @@ -110,6 +110,7 @@ CPPFLAGS-tst-longjmp_chk2.c += -D_FORTIFY_SOURCE=1 CFLAGS-tst-longjmp_chk3.c += -fexceptions -fasynchronous-unwind-tables CPPFLAGS-tst-longjmp_chk3.c += -D_FORTIFY_SOURCE=1 CPPFLAGS-tst-realpath-chk.c += -D_FORTIFY_SOURCE=2 +CPPFLAGS-tst-read-chk-cancel.c += -D_FORTIFY_SOURCE=2 # _FORTIFY_SOURCE tests. # Auto-generate tests for _FORTIFY_SOURCE for different levels, compilers and @@ -204,6 +205,10 @@ ifeq ($(have-ssp),yes) tests += tst-ssp-1 endif +ifeq ($(have-thread-library), yes) +tests += tst-read-chk-cancel +endif + ifeq (,$(CXX)) tests-unsupported = $(tests-cc-chk) endif @@ -242,3 +247,5 @@ $(objpfx)xtrace: xtrace.sh -e 's|@BINDIR@|$(bindir)|' -e 's|@PKGVERSION@|$(PKGVERSION)|' \ -e 's|@REPORT_BUGS_TO@|$(REPORT_BUGS_TO)|' $^ > $@.new \ && rm -f $@ && mv $@.new $@ && chmod +x $@ + +$(objpfx)tst-read-chk-cancel: $(shared-thread-library) diff --git a/debug/read_chk.c b/debug/read_chk.c index 0cd58db8cb..274b4f93e9 100644 --- a/debug/read_chk.c +++ b/debug/read_chk.c @@ -16,12 +16,6 @@ . */ #include -#include -#ifdef HAVE_INLINED_SYSCALLS -# include -# include -#endif - ssize_t __read_chk (int fd, void *buf, size_t nbytes, size_t buflen) @@ -29,9 +23,5 @@ __read_chk (int fd, void *buf, size_t nbytes, size_t buflen) if (nbytes > buflen) __chk_fail (); -#ifdef HAVE_INLINED_SYSCALLS - return INLINE_SYSCALL (read, 3, fd, buf, nbytes); -#else return __read (fd, buf, nbytes); -#endif } diff --git a/debug/tst-read-chk-cancel.c b/debug/tst-read-chk-cancel.c new file mode 100644 index 0000000000..7e06afb596 --- /dev/null +++ b/debug/tst-read-chk-cancel.c @@ -0,0 +1,50 @@ +/* Test that __read_chk is a cancellation point (BZ #29274) + Copyright (C) 2022 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 + . */ + +#include +#include +#include + +static int pipe_fds[2]; +static pthread_barrier_t barrier; + +static void * +read_thread (void *n) +{ + xpthread_barrier_wait (&barrier); + char c; + /* This call should be forwarded to __read_chk because the buffer size + is known, but the read length is non-constant. */ + if (read (pipe_fds[0], &c, (uintptr_t) n) != 1) + return (void *) -1L; + return 0; +} + +static int +do_test (void) +{ + xpthread_barrier_init (&barrier, 0, 2); + xpipe (pipe_fds); + pthread_t thr = xpthread_create (0, read_thread, (void *) 1L); + xpthread_barrier_wait (&barrier); + xpthread_cancel (thr); + xpthread_join (thr); + return 0; +} + +#include -- cgit 1.4.1