| Message ID | 20170214213941.3026318-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Feb 14, 2017 at 10:39:28PM +0100, Arnd Bergmann wrote: > This mirrors commit e9c38ceba8d9 ("ARM: 8455/1: define __BUG as > asm(BUG_INSTR) without CONFIG_BUG") to make the behavior of > arm64 consistent with arm and x86, and avoids lots of warnings in > randconfig builds, such as: > > kernel/seccomp.c: In function '__seccomp_filter': > kernel/seccomp.c:666:1: error: no return statement in function returning non-void [-Werror=return-type] > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/arm64/include/asm/bug.h | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/bug.h b/arch/arm64/include/asm/bug.h > index 561190d15881..461751429fc3 100644 > --- a/arch/arm64/include/asm/bug.h > +++ b/arch/arm64/include/asm/bug.h > @@ -20,9 +20,10 @@ > > #include <asm/brk-imm.h> > > -#ifdef CONFIG_GENERIC_BUG > #define HAVE_ARCH_BUG > > +#ifdef CONFIG_GENERIC_BUG > + > #ifdef CONFIG_DEBUG_BUGVERBOSE > #define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line) > #define __BUGVERBOSE_LOCATION(file, line) \ > @@ -57,6 +58,14 @@ _BUGVERBOSE_LOCATION(__FILE__, __LINE__) \ > > #define __WARN_TAINT(taint) _BUG_FLAGS(BUGFLAG_TAINT(taint)) > > +#else > + > +#define BUG() do { \ > + asm volatile("brk %[imm]" \ > + :: [imm] "i" (BUG_BRK_IMM)); \ > + unreachable(); \ > +} while (0) Do we need to duplicate the asm, or can we reuse the existing BUG definition in this header? The only extra thing we do is push a __bug_table entry, but I can't see why that would be a problem. Will
On Wed, Feb 15, 2017 at 12:22 PM, Will Deacon <will.deacon@arm.com> wrote: > On Tue, Feb 14, 2017 at 10:39:28PM +0100, Arnd Bergmann wrote: >> @@ -57,6 +58,14 @@ _BUGVERBOSE_LOCATION(__FILE__, __LINE__) \ >> >> #define __WARN_TAINT(taint) _BUG_FLAGS(BUGFLAG_TAINT(taint)) >> >> +#else >> + >> +#define BUG() do { \ >> + asm volatile("brk %[imm]" \ >> + :: [imm] "i" (BUG_BRK_IMM)); \ >> + unreachable(); \ >> +} while (0) > > Do we need to duplicate the asm, or can we reuse the existing BUG > definition in this header? The only extra thing we do is push a __bug_table > entry, but I can't see why that would be a problem. The only reason for turning off CONFIG_BUG is to save a little extra space in the kernel image, so I think we really don't want the __bug_table to be generated. However, we could split the existing asm in two and have only one definition for the asm containing the brk instruction. Arnd
diff --git a/arch/arm64/include/asm/bug.h b/arch/arm64/include/asm/bug.h index 561190d15881..461751429fc3 100644 --- a/arch/arm64/include/asm/bug.h +++ b/arch/arm64/include/asm/bug.h @@ -20,9 +20,10 @@ #include <asm/brk-imm.h> -#ifdef CONFIG_GENERIC_BUG #define HAVE_ARCH_BUG +#ifdef CONFIG_GENERIC_BUG + #ifdef CONFIG_DEBUG_BUGVERBOSE #define _BUGVERBOSE_LOCATION(file, line) __BUGVERBOSE_LOCATION(file, line) #define __BUGVERBOSE_LOCATION(file, line) \ @@ -57,6 +58,14 @@ _BUGVERBOSE_LOCATION(__FILE__, __LINE__) \ #define __WARN_TAINT(taint) _BUG_FLAGS(BUGFLAG_TAINT(taint)) +#else + +#define BUG() do { \ + asm volatile("brk %[imm]" \ + :: [imm] "i" (BUG_BRK_IMM)); \ + unreachable(); \ +} while (0) + #endif /* ! CONFIG_GENERIC_BUG */ #include <asm-generic/bug.h>
This mirrors commit e9c38ceba8d9 ("ARM: 8455/1: define __BUG as asm(BUG_INSTR) without CONFIG_BUG") to make the behavior of arm64 consistent with arm and x86, and avoids lots of warnings in randconfig builds, such as: kernel/seccomp.c: In function '__seccomp_filter': kernel/seccomp.c:666:1: error: no return statement in function returning non-void [-Werror=return-type] Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/arm64/include/asm/bug.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)