* [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning @ 2018-05-28 14:17 Christophe Leroy 2018-05-28 14:37 ` Segher Boessenkool 2018-05-28 14:39 ` Christophe Leroy 0 siblings, 2 replies; 6+ messages in thread From: Christophe Leroy @ 2018-05-28 14:17 UTC (permalink / raw) To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, segher Cc: linux-kernel, linuxppc-dev Latest GCC version emit many warnings similar to the following one. As arch/powerpc code is built with -Werror, this breaks build with GCC 8.1 This patch inhibits that warning Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> --- arch/powerpc/Makefile | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 26ccd0b91512..d6c557530ce8 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -145,6 +145,8 @@ CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions) CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD) CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata) +CFLAGS-y += $(call cc-option,-Wno-attribute-alias) + ifeq ($(CONFIG_PPC_BOOK3S_64),y) ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y) CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8 -- 2.13.3 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning 2018-05-28 14:17 [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning Christophe Leroy @ 2018-05-28 14:37 ` Segher Boessenkool 2018-05-28 14:56 ` Christophe LEROY 2018-05-28 14:39 ` Christophe Leroy 1 sibling, 1 reply; 6+ messages in thread From: Segher Boessenkool @ 2018-05-28 14:37 UTC (permalink / raw) To: Christophe Leroy Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, linux-kernel, linuxppc-dev On Mon, May 28, 2018 at 02:17:49PM +0000, Christophe Leroy wrote: > Latest GCC version emit many warnings similar to the following one. You didn't actually show an example? This warning should detect serious problems, so don't disable it without first investigating please. What do you call "latest version", btw? Trunk, aka 9.0? Or the most advanced release, 8.1? Or the latest release (which also is 8.1 :-) ) Segher ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning 2018-05-28 14:37 ` Segher Boessenkool @ 2018-05-28 14:56 ` Christophe LEROY 0 siblings, 0 replies; 6+ messages in thread From: Christophe LEROY @ 2018-05-28 14:56 UTC (permalink / raw) To: Segher Boessenkool Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, linux-kernel, linuxppc-dev Le 28/05/2018 à 16:37, Segher Boessenkool a écrit : > On Mon, May 28, 2018 at 02:17:49PM +0000, Christophe Leroy wrote: >> Latest GCC version emit many warnings similar to the following one. > > You didn't actually show an example? Yes I forgot: In file included from arch/powerpc/kernel/syscalls.c:24: ./include/linux/syscalls.h:233:18: warning: 'sys_mmap2' alias between functions of incompatible types 'long int(long unsigned int, size_t, long unsigned int, long unsigned int, long unsigned int, long unsigned int)' {aka 'long int(long unsigned int, unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:65:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:238:18: note: aliased declaration here asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~~~~~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:65:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ > > This warning should detect serious problems, so don't disable it without > first investigating please. It's been a discussion on this topic, ref https://lkml.org/lkml/2017/12/5/581 It says "The new warning seems reasonable in principle, but it doesn't help us here, since we rely on the type mismatch to sanitize the system call arguments. After I reported this as GCC PR82435, a new -Wno-attribute-alias option was added that could be used to turn the warning off globally on the command line, but I'd prefer to do it a little more fine-grained" > > What do you call "latest version", btw? Trunk, aka 9.0? Or the most > advanced release, 8.1? Or the latest release (which also is 8.1 :-) ) I encounter it with 8.1 According the refered discusion, it linked to GCC 8 Christophe > > > Segher > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning 2018-05-28 14:17 [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning Christophe Leroy 2018-05-28 14:37 ` Segher Boessenkool @ 2018-05-28 14:39 ` Christophe Leroy 2018-05-28 15:07 ` Segher Boessenkool 1 sibling, 1 reply; 6+ messages in thread From: Christophe Leroy @ 2018-05-28 14:39 UTC (permalink / raw) To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, segher Cc: linuxppc-dev, linux-kernel On 05/28/2018 02:17 PM, Christophe Leroy wrote: > Latest GCC version emit many warnings similar to the following one. Oops, forgot to include the failure text: In file included from arch/powerpc/kernel/syscalls.c:24: ./include/linux/syscalls.h:233:18: warning: 'sys_mmap2' alias between functions of incompatible types 'long int(long unsigned int, size_t, long unsigned int, long unsigned int, long unsigned int, long unsigned int)' {aka 'long int(long unsigned int, unsigned int, long unsigned int, long unsigned int, long unsigned int, long unsigned int)'} and 'long int(long int, long int, long int, long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:65:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:238:18: note: aliased declaration here asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~~~~~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:65:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:233:18: warning: 'sys_mmap' alias between functions of incompatible types 'long int(long unsigned int, size_t, long unsigned int, long unsigned int, long unsigned int, off_t)' {aka 'long int(long unsigned int, unsigned int, long unsigned int, long unsigned int, long unsigned int, long int)'} and 'long int(long int, long int, long int, long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:72:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:238:18: note: aliased declaration here asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~~~~~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:216:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/syscalls.c:72:1: note: in expansion of macro 'SYSCALL_DEFINE6' SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len, ^~~~~~~~~~~~~~~ CC arch/powerpc/kernel/irq.o CC arch/powerpc/kernel/align.o CC arch/powerpc/kernel/signal_32.o In file included from arch/powerpc/kernel/signal_32.c:29: ./include/linux/syscalls.h:233:18: warning: 'sys_swapcontext' alias between functions of incompatible types 'long int(struct ucontext *, struct ucontext *, long int)' and 'long int(long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:213:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/signal_32.c:1044:1: note: in expansion of macro 'SYSCALL_DEFINE3' SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:238:18: note: aliased declaration here asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~~~~~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:213:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/signal_32.c:1044:1: note: in expansion of macro 'SYSCALL_DEFINE3' SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:233:18: warning: 'sys_debug_setcontext' alias between functions of incompatible types 'long int(struct ucontext *, int, struct sig_dbg_op *)' and 'long int(long int, long int, long int)' [-Wattribute-alias] asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ ^~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:213:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/signal_32.c:1232:1: note: in expansion of macro 'SYSCALL_DEFINE3' SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, ^~~~~~~~~~~~~~~ ./include/linux/syscalls.h:238:18: note: aliased declaration here asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^~~~~~~~ ./include/linux/syscalls.h:222:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^~~~~~~~~~~~~~~~~ ./include/linux/syscalls.h:213:36: note: in expansion of macro 'SYSCALL_DEFINEx' #define SYSCALL_DEFINE3(name, ...) SYSCALL_DEFINEx(3, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~ arch/powerpc/kernel/signal_32.c:1232:1: note: in expansion of macro 'SYSCALL_DEFINE3' SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, ^~~~~~~~~~~~~~~ Christophe > > As arch/powerpc code is built with -Werror, this breaks build with > GCC 8.1 > > This patch inhibits that warning > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> > --- > arch/powerpc/Makefile | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile > index 26ccd0b91512..d6c557530ce8 100644 > --- a/arch/powerpc/Makefile > +++ b/arch/powerpc/Makefile > @@ -145,6 +145,8 @@ CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions) > CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD) > CFLAGS-$(CONFIG_PPC32) += $(call cc-option,-mno-readonly-in-sdata) > > +CFLAGS-y += $(call cc-option,-Wno-attribute-alias) > + > ifeq ($(CONFIG_PPC_BOOK3S_64),y) > ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y) > CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8 > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning 2018-05-28 14:39 ` Christophe Leroy @ 2018-05-28 15:07 ` Segher Boessenkool 2018-05-28 16:18 ` Mathieu Malaterre 0 siblings, 1 reply; 6+ messages in thread From: Segher Boessenkool @ 2018-05-28 15:07 UTC (permalink / raw) To: Christophe Leroy Cc: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, linuxppc-dev, linux-kernel On Mon, May 28, 2018 at 02:39:37PM +0000, Christophe Leroy wrote: > In file included from arch/powerpc/kernel/syscalls.c:24: > ./include/linux/syscalls.h:233:18: warning: 'sys_mmap2' alias between > functions of incompatible types 'long int(long unsigned int, size_t, > long unsigned int, long unsigned int, long unsigned int, long > unsigned int)' {aka 'long int(long unsigned int, unsigned int, long > unsigned int, long unsigned int, long unsigned int, long unsigned > int)'} and 'long int(long int, long int, long int, long int, long > int, long int)' [-Wattribute-alias] So yes, these are actually different (int vs. long). > In file included from arch/powerpc/kernel/signal_32.c:29: > ./include/linux/syscalls.h:233:18: warning: 'sys_swapcontext' alias > between functions of incompatible types 'long int(struct ucontext *, > struct ucontext *, long int)' and 'long int(long int, long int, long > int)' [-Wattribute-alias] And this one is quite spectacularly different. Try putting this before the wacko aliases: #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wattribute-alias" and this after: #pragma GCC diagnostic pop so that you will get this quite useful warning for all other code. Segher ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning 2018-05-28 15:07 ` Segher Boessenkool @ 2018-05-28 16:18 ` Mathieu Malaterre 0 siblings, 0 replies; 6+ messages in thread From: Mathieu Malaterre @ 2018-05-28 16:18 UTC (permalink / raw) To: Segher Boessenkool; +Cc: Christophe Leroy, Paul Mackerras, linuxppc-dev, LKML On Mon, May 28, 2018 at 5:07 PM, Segher Boessenkool <segher@kernel.crashing.org> wrote: > On Mon, May 28, 2018 at 02:39:37PM +0000, Christophe Leroy wrote: >> In file included from arch/powerpc/kernel/syscalls.c:24: >> ./include/linux/syscalls.h:233:18: warning: 'sys_mmap2' alias between >> functions of incompatible types 'long int(long unsigned int, size_t, >> long unsigned int, long unsigned int, long unsigned int, long >> unsigned int)' {aka 'long int(long unsigned int, unsigned int, long >> unsigned int, long unsigned int, long unsigned int, long unsigned >> int)'} and 'long int(long int, long int, long int, long int, long >> int, long int)' [-Wattribute-alias] > > So yes, these are actually different (int vs. long). > >> In file included from arch/powerpc/kernel/signal_32.c:29: >> ./include/linux/syscalls.h:233:18: warning: 'sys_swapcontext' alias >> between functions of incompatible types 'long int(struct ucontext *, >> struct ucontext *, long int)' and 'long int(long int, long int, long >> int)' [-Wattribute-alias] > > And this one is quite spectacularly different. https://patchwork.kernel.org/patch/10375607/ > > Try putting this before the wacko aliases: > > #pragma GCC diagnostic push > #pragma GCC diagnostic ignored "-Wattribute-alias" > > and this after: > > #pragma GCC diagnostic pop > > so that you will get this quite useful warning for all other code. > > > Segher ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-05-28 16:18 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-05-28 14:17 [PATCH] powerpc/Makefile: fix build failure by disabling attribute-alias warning Christophe Leroy 2018-05-28 14:37 ` Segher Boessenkool 2018-05-28 14:56 ` Christophe LEROY 2018-05-28 14:39 ` Christophe Leroy 2018-05-28 15:07 ` Segher Boessenkool 2018-05-28 16:18 ` Mathieu Malaterre
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