| Message ID | 20211021221627.5d7270de@rorschach.local.home (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ftrace/sh: Add arch_ftrace_ops_list_func stub to have compressed image still link | expand |
Hi Steven,
I love your patch! Perhaps something to improve:
[auto build test WARNING on linux/master]
[also build test WARNING on hnaz-mm/master linus/master v5.15-rc7 next-20211026]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Steven-Rostedt/ftrace-sh-Add-arch_ftrace_ops_list_func-stub-to-have-compressed-image-still-link/20211022-101651
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2f111a6fd5b5297b4e92f53798ca086f7c7d33a4
config: sh-se7705_defconfig (attached as .config)
compiler: sh4-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/0day-ci/linux/commit/67866b4041f96ae1a8bc1b0b0d077c13c59a0e24
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Steven-Rostedt/ftrace-sh-Add-arch_ftrace_ops_list_func-stub-to-have-compressed-image-still-link/20211022-101651
git checkout 67866b4041f96ae1a8bc1b0b0d077c13c59a0e24
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=sh
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
arch/sh/boot/compressed/misc.c:109:6: warning: no previous prototype for '__stack_chk_fail' [-Wmissing-prototypes]
109 | void __stack_chk_fail(void)
| ^~~~~~~~~~~~~~~~
arch/sh/boot/compressed/misc.c:115:6: warning: no previous prototype for 'ftrace_stub' [-Wmissing-prototypes]
115 | void ftrace_stub(void)
| ^~~~~~~~~~~
>> arch/sh/boot/compressed/misc.c:118:6: warning: no previous prototype for 'arch_ftrace_ops_list_func' [-Wmissing-prototypes]
118 | void arch_ftrace_ops_list_func(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
arch/sh/boot/compressed/misc.c:128:6: warning: no previous prototype for 'decompress_kernel' [-Wmissing-prototypes]
128 | void decompress_kernel(void)
| ^~~~~~~~~~~~~~~~~
vim +/arch_ftrace_ops_list_func +118 arch/sh/boot/compressed/misc.c
113
114 /* Needed because vmlinux.lds.h references this */
115 void ftrace_stub(void)
116 {
117 }
> 118 void arch_ftrace_ops_list_func(void)
119 {
120 }
121
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c index a03b6680a9d9..ca05c99a3d5b 100644 --- a/arch/sh/boot/compressed/misc.c +++ b/arch/sh/boot/compressed/misc.c @@ -115,6 +115,9 @@ void __stack_chk_fail(void) void ftrace_stub(void) { } +void arch_ftrace_ops_list_func(void) +{ +} #define stackalign 4
Using the linker script to fix an issue where some archs call the function tracer with just the ip (instruction pointer) and pip (parent instruction pointer) where as more up to date archs also pass in the associated ftrace_ops and the ftrace_regs pointer, the generic code will be called either with two parameters or four. To avoid any C undefined behavior of calling two parameters to four or four to two parameter function, two functions are created, where a preprocessor macro uses the one that matches the architecture. As the function pointers for them may be different, a typecast is used. But this triggers issues with newer compilers that will fail due to -Werror. A linker trick is now used to map the generic function to the function that is used (note the generic function is only used to set the default function callback). The linker trick defines ftrace_ops_list_func (the generic function) to arch_ftrace_ops_list_func (the arch defined one). Link: https://lore.kernel.org/all/20200617165616.52241bde@oasis.local.home/ But this fails sh arch because their linker script is included in their compressed image that does not define arch_ftrace_ops_list_func at all sh4-linux-ld:arch/sh/boot/compressed/../../kernel/vmlinux.lds:32: undefined symbol `arch_ftrace_ops_list_func' referenced in expression Included a stub by that name in the misc.c to allow the code to compile and link, even though it's not used. This is similar to what was done for ftrace_stub: b83b43ffc6e4b ("fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> --- This is based on my tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git branch: ftrace/core I can push this change through my tree with the SuperH maintainer's acks.