On Wed, Mar 13, 2024 at 10:12:29AM -0700, Nathan Chancellor wrote:
Hi Sasha,
On Wed, Mar 13, 2024 at 12:41:52PM -0400, Sasha Levin wrote:
From: Nathan Chancellor nathan@kernel.org
[ Upstream commit 397586506c3da005b9333ce5947ad01e8018a3be ]
After the linked LLVM change, building ARCH=um defconfig results in a segmentation fault in modpost. Prior to commit a23e7584ecf3 ("modpost: unify 'sym' and 'to' in default_mismatch_handler()"), there was a warning:
WARNING: modpost: vmlinux.o(__ex_table+0x88): Section mismatch in reference to the .ltext:(unknown) WARNING: modpost: The relocation at __ex_table+0x88 references section ".ltext" which is not in the list of authorized sections. If you're adding a new section and/or if this reference is valid, add ".ltext" to the list of authorized sections to jump to on fault. This can be achieved by adding ".ltext" to OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.
The linked LLVM change moves global objects to the '.ltext' (and '.ltext.*' with '-ffunction-sections') sections with '-mcmodel=large', which ARCH=um uses. These sections should be handled just as '.text' and '.text.*' are, so add them to TEXT_SECTIONS.
Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1981 Link: https://github.com/llvm/llvm-project/commit/4bf8a688956a759b7b6b8d94f42d25c1... Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org
This causes a warning when building with HOSTCC=clang:
scripts/mod/modpost.c:1123:37: warning: excess elements in array initializer [-Wexcess-initializers] 1123 | .good_tosec = {ALL_TEXT_SECTIONS , NULL}, | ^~~~ .../lib/clang/17/include/stddef.h:89:16: note: expanded from macro 'NULL' 89 | # define NULL ((void*)0) | ^~~~~~~~~~ 1 warning generated.
Same comment as on the other UML clang-18 patch, I do not think this is necessary right now in 5.15 and earlier. The other modpost patch can go as well, as it is only a prerequisite change.
Dropped, thanks!