From: Greg Kroah-Hartman Date: Thu, 17 Apr 2025 17:13:03 +0000 (+0200) Subject: 6.12-stable patches X-Git-Tag: v6.12.24~22 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=147638b060060f4dcae1f1f7b2292ec754e21fa9;p=thirdparty%2Fkernel%2Fstable-queue.git 6.12-stable patches added patches: kbuild-add-fno-builtin-wcslen.patch --- diff --git a/queue-6.12/kbuild-add-fno-builtin-wcslen.patch b/queue-6.12/kbuild-add-fno-builtin-wcslen.patch new file mode 100644 index 0000000000..06688ec642 --- /dev/null +++ b/queue-6.12/kbuild-add-fno-builtin-wcslen.patch @@ -0,0 +1,59 @@ +From 99d01048fc148dc10471b67da642df190a9727bb Mon Sep 17 00:00:00 2001 +From: Nathan Chancellor +Date: Mon, 7 Apr 2025 16:22:12 -0700 +Subject: kbuild: Add '-fno-builtin-wcslen' + +From: Nathan Chancellor + +commit 84ffc79bfbf70c779e60218563f2f3ad45288671 upstream. + +A recent optimization change in LLVM [1] aims to transform certain loop +idioms into calls to strlen() or wcslen(). This change transforms the +first while loop in UniStrcat() into a call to wcslen(), breaking the +build when UniStrcat() gets inlined into alloc_path_with_tree_prefix(): + + ld.lld: error: undefined symbol: wcslen + >>> referenced by nls_ucs2_utils.h:54 (fs/smb/client/../../nls/nls_ucs2_utils.h:54) + >>> vmlinux.o:(alloc_path_with_tree_prefix) + >>> referenced by nls_ucs2_utils.h:54 (fs/smb/client/../../nls/nls_ucs2_utils.h:54) + >>> vmlinux.o:(alloc_path_with_tree_prefix) + +Disable this optimization with '-fno-builtin-wcslen', which prevents the +compiler from assuming that wcslen() is available in the kernel's C +library. + +[ More to the point - it's not that we couldn't implement wcslen(), it's + that this isn't an optimization at all in the context of the kernel. + + Replacing a simple inlined loop with a function call to the same loop + is just stupid and pointless if you don't have long strings and fancy + libraries with vectorization support etc. + + For the regular 'strlen()' cases, we want the compiler to do this in + order to handle the trivial case of constant strings. And we do have + optimized versions of 'strlen()' on some architectures. But for + wcslen? Just no. - Linus ] + +Cc: stable@vger.kernel.org +Link: https://github.com/llvm/llvm-project/commit/9694844d7e36fd5e01011ab56b64f27b867aa72d [1] +Signed-off-by: Nathan Chancellor +Signed-off-by: Linus Torvalds +[nathan: Resolve small conflict in older trees] +Signed-off-by: Nathan Chancellor +Signed-off-by: Greg Kroah-Hartman +--- + Makefile | 3 +++ + 1 file changed, 3 insertions(+) + +--- a/Makefile ++++ b/Makefile +@@ -1013,6 +1013,9 @@ ifdef CONFIG_CC_IS_GCC + KBUILD_CFLAGS += -fconserve-stack + endif + ++# Ensure compilers do not transform certain loops into calls to wcslen() ++KBUILD_CFLAGS += -fno-builtin-wcslen ++ + # change __FILE__ to the relative path from the srctree + KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) + diff --git a/queue-6.12/series b/queue-6.12/series index 8015f32ca0..5271b595b2 100644 --- a/queue-6.12/series +++ b/queue-6.12/series @@ -387,3 +387,4 @@ nfsd-fix-cb_getattr-status-fix.patch nfsd-don-t-ignore-the-return-code-of-svc_proc_register.patch x86-e820-fix-handling-of-subpage-regions-when-calculating-nosave-ranges-in-e820__register_nosave_regions.patch libbpf-prevent-compiler-warnings-errors.patch +kbuild-add-fno-builtin-wcslen.patch