5.10-stable patches

added patches:
	kbuild-disable-wdefault-const-init-unsafe.patch

diff --git a/queue-5.10/kbuild-disable-wdefault-const-init-unsafe.patch b/queue-5.10/kbuild-disable-wdefault-const-init-unsafe.patch
new file mode 100644 (file)
index 0000000..497c8ab
--- /dev/null
+++ b/queue-5.10/kbuild-disable-wdefault-const-init-unsafe.patch
@@ -0,0 +1,112 @@
+From 3b25f5705a71b11c73c3bb0e8cbe2bfa10a0a58a Mon Sep 17 00:00:00 2001
+From: Nathan Chancellor <nathan@kernel.org>
+Date: Tue, 6 May 2025 14:02:01 -0700
+Subject: kbuild: Disable -Wdefault-const-init-unsafe
+
+From: Nathan Chancellor <nathan@kernel.org>
+
+commit d0afcfeb9e3810ec89d1ffde1a0e36621bb75dca upstream.
+
+A new on by default warning in clang [1] aims to flags instances where
+const variables without static or thread local storage or const members
+in aggregate types are not initialized because it can lead to an
+indeterminate value. This is quite noisy for the kernel due to
+instances originating from header files such as:
+
+  drivers/gpu/drm/i915/gt/intel_ring.h:62:2: error: default initialization of an object of type 'typeof (ring->size)' (aka 'const unsigned int') leaves the object uninitialized [-Werror,-Wdefault-const-init-var-unsafe]
+     62 |         typecheck(typeof(ring->size), next);
+        |         ^
+  include/linux/typecheck.h:10:9: note: expanded from macro 'typecheck'
+     10 | ({      type __dummy; \
+        |              ^
+
+  include/net/ip.h:478:14: error: default initialization of an object of type 'typeof (rt->dst.expires)' (aka 'const unsigned long') leaves the object uninitialized [-Werror,-Wdefault-const-init-var-unsafe]
+    478 |                 if (mtu && time_before(jiffies, rt->dst.expires))
+        |                            ^
+  include/linux/jiffies.h:138:26: note: expanded from macro 'time_before'
+    138 | #define time_before(a,b)        time_after(b,a)
+        |                                 ^
+  include/linux/jiffies.h:128:3: note: expanded from macro 'time_after'
+    128 |         (typecheck(unsigned long, a) && \
+        |          ^
+  include/linux/typecheck.h:11:12: note: expanded from macro 'typecheck'
+     11 |         typeof(x) __dummy2; \
+        |                   ^
+
+  include/linux/list.h:409:27: warning: default initialization of an object of type 'union (unnamed union at include/linux/list.h:409:27)' with const member leaves the object uninitialized [-Wdefault-const-init-field-unsafe]
+    409 |         struct list_head *next = smp_load_acquire(&head->next);
+        |                                  ^
+  include/asm-generic/barrier.h:176:29: note: expanded from macro 'smp_load_acquire'
+    176 | #define smp_load_acquire(p) __smp_load_acquire(p)
+        |                             ^
+  arch/arm64/include/asm/barrier.h:164:59: note: expanded from macro '__smp_load_acquire'
+    164 |         union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u;   \
+        |                                                                  ^
+  include/linux/list.h:409:27: note: member '__val' declared 'const' here
+
+  crypto/scatterwalk.c:66:22: error: default initialization of an object of type 'struct scatter_walk' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe]
+     66 |         struct scatter_walk walk;
+        |                             ^
+  include/crypto/algapi.h:112:15: note: member 'addr' declared 'const' here
+    112 |                 void *const addr;
+        |                             ^
+
+  fs/hugetlbfs/inode.c:733:24: error: default initialization of an object of type 'struct vm_area_struct' with const member leaves the object uninitialized [-Werror,-Wdefault-const-init-field-unsafe]
+    733 |         struct vm_area_struct pseudo_vma;
+        |                               ^
+  include/linux/mm_types.h:803:20: note: member 'vm_flags' declared 'const' here
+    803 |                 const vm_flags_t vm_flags;
+        |                                  ^
+
+Silencing the instances from typecheck.h is difficult because '= {}' is
+not available in older but supported compilers and '= {0}' would cause
+warnings about a literal 0 being treated as NULL. While it might be
+possible to come up with a local hack to silence the warning for
+clang-21+, it may not be worth it since -Wuninitialized will still
+trigger if an uninitialized const variable is actually used.
+
+In all audited cases of the "field" variant of the warning, the members
+are either not used in the particular call path, modified through other
+means such as memset() / memcpy() because the containing object is not
+const, or are within a union with other non-const members.
+
+Since this warning does not appear to have a high signal to noise ratio,
+just disable it.
+
+Cc: stable@vger.kernel.org
+Link: https://github.com/llvm/llvm-project/commit/576161cb6069e2c7656a8ef530727a0f4aefff30 [1]
+Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
+Closes: https://lore.kernel.org/CA+G9fYuNjKcxFKS_MKPRuga32XbndkLGcY-PVuoSwzv6VWbY=w@mail.gmail.com/
+Reported-by: Marcus Seyfarth <m.seyfarth@gmail.com>
+Closes: https://github.com/ClangBuiltLinux/linux/issues/2088
+Signed-off-by: Nathan Chancellor <nathan@kernel.org>
+Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
+[nathan: Apply change to Makefile instead of scripts/Makefile.extrawarn
+         due to lack of e88ca24319e4 in older stable branches]
+Signed-off-by: Nathan Chancellor <nathan@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Makefile |   12 ++++++++++++
+ 1 file changed, 12 insertions(+)
+
+--- a/Makefile
++++ b/Makefile
+@@ -795,6 +795,18 @@ KBUILD_CFLAGS += -Wno-gnu
+ # source of a reference will be _MergedGlobals and not on of the whitelisted names.
+ # See modpost pattern 2
+ KBUILD_CFLAGS += -mno-global-merge
++
++# Clang may emit a warning when a const variable, such as the dummy variables
++# in typecheck(), or const member of an aggregate type are not initialized,
++# which can result in unexpected behavior. However, in many audited cases of
++# the "field" variant of the warning, this is intentional because the field is
++# never used within a particular call path, the field is within a union with
++# other non-const members, or the containing object is not const so the field
++# can be modified via memcpy() / memset(). While the variable warning also gets
++# disabled with this same switch, there should not be too much coverage lost
++# because -Wuninitialized will still flag when an uninitialized const variable
++# is used.
++KBUILD_CFLAGS += $(call cc-disable-warning, default-const-init-unsafe)
+ else
+ 
+ # Warn about unmarked fall-throughs in switch statement.

diff --git a/queue-5.10/series b/queue-5.10/series
index 2646bbcda55f78363d1e3a43d07b8f5abab10c99..66784b0d719345df3f66e87a4f472a082811633a 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -249,3 +249,4 @@ mm-page_alloc.c-avoid-infinite-retries-caused-by-cpuset-race.patch
 spi-spi-fsl-dspi-restrict-register-range-for-regmap-.patch
 spi-spi-fsl-dspi-halt-the-module-after-a-new-message.patch
 spi-spi-fsl-dspi-reset-sr-flags-before-sending-a-new.patch
+kbuild-disable-wdefault-const-init-unsafe.patch