| Message ID | 1564774882-22926-1-git-send-email-cai@lca.pw (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | asm-generic: fix variable 'p4d' set but not used | expand |
On Fri, Aug 02, 2019 at 03:41:22PM -0400, Qian Cai wrote: > GCC throws a warning on an arm64 system since the commit 9849a5697d3d > ("arch, mm: convert all architectures to use 5level-fixup.h"), > > mm/kasan/init.c: In function 'kasan_free_p4d': > mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used > [-Wunused-but-set-variable] > p4d_t *p4d; > ^~~ > > because p4d_none() in "5level-fixup.h" is compiled away while it is a > static inline function in "pgtable-nopud.h". However, if converted > p4d_none() to a static inline there, powerpc would be unhappy as it > reads those in assembler language in > "arch/powerpc/include/asm/book3s/64/pgtable.h", > > ./include/asm-generic/5level-fixup.h: Assembler messages: > ./include/asm-generic/5level-fixup.h:20: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:21: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:22: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:23: Error: junk at end of line, > first unrecognized character is `}' > ./include/asm-generic/5level-fixup.h:25: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:26: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:27: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:28: Error: junk at end of line, > first unrecognized character is `}' > ./include/asm-generic/5level-fixup.h:30: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:31: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:32: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:33: Error: junk at end of line, > first unrecognized character is `}' > make[2]: *** [scripts/Makefile.build:375: > arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 > > Fix it by reference the variable in the macro instead. > > Signed-off-by: Qian Cai <cai@lca.pw> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
On Fri, Aug 02, 2019 at 03:41:22PM -0400, Qian Cai wrote: > GCC throws a warning on an arm64 system since the commit 9849a5697d3d > ("arch, mm: convert all architectures to use 5level-fixup.h"), > > mm/kasan/init.c: In function 'kasan_free_p4d': > mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used > [-Wunused-but-set-variable] > p4d_t *p4d; > ^~~ > > because p4d_none() in "5level-fixup.h" is compiled away while it is a > static inline function in "pgtable-nopud.h". However, if converted > p4d_none() to a static inline there, powerpc would be unhappy as it > reads those in assembler language in > "arch/powerpc/include/asm/book3s/64/pgtable.h", > > ./include/asm-generic/5level-fixup.h: Assembler messages: > ./include/asm-generic/5level-fixup.h:20: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:21: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:22: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:23: Error: junk at end of line, > first unrecognized character is `}' > ./include/asm-generic/5level-fixup.h:25: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:26: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:27: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:28: Error: junk at end of line, > first unrecognized character is `}' > ./include/asm-generic/5level-fixup.h:30: Error: unrecognized opcode: > `static' > ./include/asm-generic/5level-fixup.h:31: Error: junk at end of line, > first unrecognized character is `{' > ./include/asm-generic/5level-fixup.h:32: Error: unrecognized opcode: > `return' > ./include/asm-generic/5level-fixup.h:33: Error: junk at end of line, > first unrecognized character is `}' > make[2]: *** [scripts/Makefile.build:375: > arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 > > Fix it by reference the variable in the macro instead. > > Signed-off-by: Qian Cai <cai@lca.pw> > include/asm-generic/5level-fixup.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h > index bb6cb347018c..2c3e14c924b6 100644 > +++ b/include/asm-generic/5level-fixup.h > @@ -19,7 +19,7 @@ > > #define p4d_alloc(mm, pgd, address) (pgd) > #define p4d_offset(pgd, start) (pgd) > -#define p4d_none(p4d) 0 > +#define p4d_none(p4d) ((void)p4d, 0) Yuk, how about a static inline instead? Jason
On Tue, 6 Aug 2019 11:39:04 -0300 Jason Gunthorpe <jgg@ziepe.ca> wrote: > On Fri, Aug 02, 2019 at 03:41:22PM -0400, Qian Cai wrote: > > GCC throws a warning on an arm64 system since the commit 9849a5697d3d > > ("arch, mm: convert all architectures to use 5level-fixup.h"), > > > > mm/kasan/init.c: In function 'kasan_free_p4d': > > mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used > > [-Wunused-but-set-variable] > > p4d_t *p4d; > > ^~~ > > > > because p4d_none() in "5level-fixup.h" is compiled away while it is a > > static inline function in "pgtable-nopud.h". However, if converted > > p4d_none() to a static inline there, powerpc would be unhappy as it > > reads those in assembler language in > > "arch/powerpc/include/asm/book3s/64/pgtable.h", > > > > ./include/asm-generic/5level-fixup.h: Assembler messages: > > ./include/asm-generic/5level-fixup.h:20: Error: unrecognized opcode: > > `static' > > ./include/asm-generic/5level-fixup.h:21: Error: junk at end of line, > > first unrecognized character is `{' > > ./include/asm-generic/5level-fixup.h:22: Error: unrecognized opcode: > > `return' > > ./include/asm-generic/5level-fixup.h:23: Error: junk at end of line, > > first unrecognized character is `}' > > ./include/asm-generic/5level-fixup.h:25: Error: unrecognized opcode: > > `static' > > ./include/asm-generic/5level-fixup.h:26: Error: junk at end of line, > > first unrecognized character is `{' > > ./include/asm-generic/5level-fixup.h:27: Error: unrecognized opcode: > > `return' > > ./include/asm-generic/5level-fixup.h:28: Error: junk at end of line, > > first unrecognized character is `}' > > ./include/asm-generic/5level-fixup.h:30: Error: unrecognized opcode: > > `static' > > ./include/asm-generic/5level-fixup.h:31: Error: junk at end of line, > > first unrecognized character is `{' > > ./include/asm-generic/5level-fixup.h:32: Error: unrecognized opcode: > > `return' > > ./include/asm-generic/5level-fixup.h:33: Error: junk at end of line, > > first unrecognized character is `}' > > make[2]: *** [scripts/Makefile.build:375: > > arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 > > > > Fix it by reference the variable in the macro instead. > > > > Signed-off-by: Qian Cai <cai@lca.pw> > > include/asm-generic/5level-fixup.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h > > index bb6cb347018c..2c3e14c924b6 100644 > > +++ b/include/asm-generic/5level-fixup.h > > @@ -19,7 +19,7 @@ > > > > #define p4d_alloc(mm, pgd, address) (pgd) > > #define p4d_offset(pgd, start) (pgd) > > -#define p4d_none(p4d) 0 > > +#define p4d_none(p4d) ((void)p4d, 0) > > Yuk, how about a static inline instead? Yes. With the appropriate `#ifndef __ASSEMBLY__' to avoid powerpc build errors?
diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h index bb6cb347018c..2c3e14c924b6 100644 --- a/include/asm-generic/5level-fixup.h +++ b/include/asm-generic/5level-fixup.h @@ -19,7 +19,7 @@ #define p4d_alloc(mm, pgd, address) (pgd) #define p4d_offset(pgd, start) (pgd) -#define p4d_none(p4d) 0 +#define p4d_none(p4d) ((void)p4d, 0) #define p4d_bad(p4d) 0 #define p4d_present(p4d) 1 #define p4d_ERROR(p4d) do { } while (0)
GCC throws a warning on an arm64 system since the commit 9849a5697d3d ("arch, mm: convert all architectures to use 5level-fixup.h"), mm/kasan/init.c: In function 'kasan_free_p4d': mm/kasan/init.c:344:9: warning: variable 'p4d' set but not used [-Wunused-but-set-variable] p4d_t *p4d; ^~~ because p4d_none() in "5level-fixup.h" is compiled away while it is a static inline function in "pgtable-nopud.h". However, if converted p4d_none() to a static inline there, powerpc would be unhappy as it reads those in assembler language in "arch/powerpc/include/asm/book3s/64/pgtable.h", ./include/asm-generic/5level-fixup.h: Assembler messages: ./include/asm-generic/5level-fixup.h:20: Error: unrecognized opcode: `static' ./include/asm-generic/5level-fixup.h:21: Error: junk at end of line, first unrecognized character is `{' ./include/asm-generic/5level-fixup.h:22: Error: unrecognized opcode: `return' ./include/asm-generic/5level-fixup.h:23: Error: junk at end of line, first unrecognized character is `}' ./include/asm-generic/5level-fixup.h:25: Error: unrecognized opcode: `static' ./include/asm-generic/5level-fixup.h:26: Error: junk at end of line, first unrecognized character is `{' ./include/asm-generic/5level-fixup.h:27: Error: unrecognized opcode: `return' ./include/asm-generic/5level-fixup.h:28: Error: junk at end of line, first unrecognized character is `}' ./include/asm-generic/5level-fixup.h:30: Error: unrecognized opcode: `static' ./include/asm-generic/5level-fixup.h:31: Error: junk at end of line, first unrecognized character is `{' ./include/asm-generic/5level-fixup.h:32: Error: unrecognized opcode: `return' ./include/asm-generic/5level-fixup.h:33: Error: junk at end of line, first unrecognized character is `}' make[2]: *** [scripts/Makefile.build:375: arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 Fix it by reference the variable in the macro instead. Signed-off-by: Qian Cai <cai@lca.pw> --- include/asm-generic/5level-fixup.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)