Messages in this thread | | | Date | Wed, 29 Apr 2020 18:11:15 -0500 | From | Josh Poimboeuf <> | Subject | Re: Remaining randconfig objtool warnings, linux-next-20200428 |
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On Thu, Apr 30, 2020 at 12:46:57AM +0200, Arnd Bergmann wrote: > On Wed, Apr 29, 2020 at 8:55 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > > On Tue, Apr 28, 2020 at 11:10:44AM -0500, Josh Poimboeuf wrote: > > > > ==> build/x86/0xE0F2ACFF_defconfig/log <== > > > > kernel/time/posix-stubs.o: warning: objtool: __x64_sys_timer_create()+0x23: sibling call from callable instruction with modified stack frame > > > > This one is fixed with the following cleanup: > > > > From: Josh Poimboeuf <jpoimboe@redhat.com> > > Subject: [PATCH] linkage: Convert syscall alias macros to C > > > > There's no need to use inline asm to create ELF alias symbols. > > Annotated C function declarations can be used instead. > > > > This also makes the ordering of the ELF symbol table more logical, with > > the real function now always coming before the aliases. This makes it > > easier for objtool, objdump and other tools to differentiate them. > > > > This fixes the following warning: > > > > kernel/time/posix-stubs.o: warning: objtool: __x64_sys_timer_create()+0x23: sibling call from callable instruction with modified stack frame > > > > Reported-by: Arnd Bergmann <arnd@arndb.de> > > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > > --- > > include/linux/linkage.h | 14 ++++---------- > > 1 file changed, 4 insertions(+), 10 deletions(-) > > Unfortunately, this patch leads to new warnings when > CONFIG_POSIX_TIMERS is disabled: > > In file included from /git/arm-soc/kernel/time/posix-stubs.c:9: > /git/arm-soc/kernel/time/posix-stubs.c:35:37: error: conflicting types > for 'sys_timer_create' > 35 | #define SYS_NI(name) SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers) > | ^~~~ > /git/arm-soc/include/linux/linkage.h:26:63: note: in definition of > macro 'SYSCALL_ALIAS' > 26 | #define SYSCALL_ALIAS(alias, name) __alias(name) typeof(name) alias > | ^~~~~ > /git/arm-soc/kernel/time/posix-stubs.c:42:1: note: in expansion of > macro 'SYS_NI' > 42 | SYS_NI(timer_create); > | ^~~~~~ > In file included from /git/arm-soc/kernel/time/posix-stubs.c:13: > /git/arm-soc/include/linux/syscalls.h:616:17: note: previous > declaration of 'sys_timer_create' was here > 616 | asmlinkage long sys_timer_create(clockid_t which_clock, > | ^~~~~~~~~~~~~~~~ > > We can probably move those SYS_NI() instances to kernel/sys_ni.c, > which does not include the header, but it's still a bit ugly. I'll try > that tomorrow > unless you come up with a better suggestion first.
Oh I guess arm32 doesn't have SYS_NI defined. All this syscall aliasing stuff is a total mystery to me.
-- Josh
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