| Message ID | 173689081941.3476119.6143322419702468919.stgit@frogsfrogsfrogs (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [1/5] xfs_db: improve error message when unknown btree type given to btheight | expand |
On Tue, Jan 14, 2025 at 01:41:25PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@kernel.org> > > Newer versions of gcc and clang can include the ability to zero stack > variables by default. Let's enable it so that we (a) reduce the risk of > writing stack contents to disk somewhere and (b) try to reduce > unpredictable program behavior based on random stack contents. The > kernel added this 6 years ago, so I think it's mature enough for > xfsprogs. Hmm, this tends to paper of bugs quite badly. But I guess we'd better paper over bugs in the same way as the kernel code. Reluctantly-Reviewed-by: Christoph Hellwig <hch@lst.de>
On Wed, Jan 15, 2025 at 06:21:55AM +0100, Christoph Hellwig wrote: > On Tue, Jan 14, 2025 at 01:41:25PM -0800, Darrick J. Wong wrote: > > From: Darrick J. Wong <djwong@kernel.org> > > > > Newer versions of gcc and clang can include the ability to zero stack > > variables by default. Let's enable it so that we (a) reduce the risk of > > writing stack contents to disk somewhere and (b) try to reduce > > unpredictable program behavior based on random stack contents. The > > kernel added this 6 years ago, so I think it's mature enough for > > xfsprogs. > > Hmm, this tends to paper of bugs quite badly. But I guess we'd better > paper over bugs in the same way as the kernel code. Yeah, I've been thinking about this one for a couple of weeks -- yeah, it does paper over uninit variable bugs, but since the kernel does it we had better do that too if we want to keep porting random kernel code to support libxfs. :/ > Reluctantly-Reviewed-by: Christoph Hellwig <hch@lst.de> Thanks for reviewing! --D
diff --git a/configure.ac b/configure.ac index 224d1d3930bf2f..90ef7925a925d0 100644 --- a/configure.ac +++ b/configure.ac @@ -177,6 +177,7 @@ AC_CONFIG_SYSTEMD_SYSTEM_UNIT_DIR AC_CONFIG_CROND_DIR AC_CONFIG_UDEV_RULE_DIR AC_HAVE_BLKID_TOPO +AC_HAVE_TRIVIAL_AUTO_VAR_INIT if test "$enable_ubsan" = "yes" || test "$enable_ubsan" = "probe"; then AC_PACKAGE_CHECK_UBSAN diff --git a/include/builddefs.in b/include/builddefs.in index ac43b6412c8cbb..82840ec7fd3adb 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -146,7 +146,7 @@ ifeq ($(HAVE_LIBURCU_ATOMIC64),yes) PCFLAGS += -DHAVE_LIBURCU_ATOMIC64 endif -SANITIZER_CFLAGS += @addrsan_cflags@ @threadsan_cflags@ @ubsan_cflags@ +SANITIZER_CFLAGS += @addrsan_cflags@ @threadsan_cflags@ @ubsan_cflags@ @autovar_init_cflags@ SANITIZER_LDFLAGS += @addrsan_ldflags@ @threadsan_ldflags@ @ubsan_ldflags@ # Use special ar/ranlib wrappers if we have lto diff --git a/m4/package_sanitizer.m4 b/m4/package_sanitizer.m4 index 41b729906a27ba..6488f7ebce2f50 100644 --- a/m4/package_sanitizer.m4 +++ b/m4/package_sanitizer.m4 @@ -57,3 +57,17 @@ AC_DEFUN([AC_PACKAGE_CHECK_THREADSAN], AC_SUBST(threadsan_cflags) AC_SUBST(threadsan_ldflags) ]) + +# Check if we have -ftrivial-auto-var-init=zero +AC_DEFUN([AC_HAVE_TRIVIAL_AUTO_VAR_INIT], + [ AC_MSG_CHECKING([if C compiler supports zeroing automatic vars]) + OLD_CFLAGS="$CFLAGS" + TEST_CFLAGS="-ftrivial-auto-var-init=zero" + CFLAGS="$CFLAGS $TEST_CFLAGS" + AC_LINK_IFELSE([AC_LANG_PROGRAM([])], + [AC_MSG_RESULT([yes])] + [autovar_init_cflags=$TEST_CFLAGS], + [AC_MSG_RESULT([no])]) + CFLAGS="${OLD_CFLAGS}" + AC_SUBST(autovar_init_cflags) + ])