On Thu, Jul 26, 2018 at 10:13:22AM +0200, Arnd Bergmann wrote: > Starting with gcc-8.1, we get a warning about all system call definitions, > which use an alias between functions with incompatible prototypes, e.g.: > > In file included from ../mm/process_vm_access.c:19: > ../include/linux/syscalls.h:211:18: warning: 'sys_process_vm_readv' alias between functions of incompatible types 'long int(pid_t, const struct iovec *, long unsigned int, const struct iovec *, long unsigned int, long unsigned int)' {aka 'long int(int, const struct iovec *, long unsigned int, const struct iovec *, 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:207:2: note: in expansion of macro '__SYSCALL_DEFINEx' > __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) > ^~~~~~~~~~~~~~~~~ > ../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx' > #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) > ^~~~~~~~~~~~~~~ > ../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6' > SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, > ^~~~~~~~~~~~~~~ > ../include/linux/syscalls.h:215:18: note: aliased declaration here > asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ > ^~~ > ../include/linux/syscalls.h:207:2: note: in expansion of macro '__SYSCALL_DEFINEx' > __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) > ^~~~~~~~~~~~~~~~~ > ../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx' > #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__) > ^~~~~~~~~~~~~~~ > ../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6' > SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec, > > This is really noisy and does not indicate a real problem. In the latest > mainline kernel, this was addressed by commit bee20031772a ("disable > -Wattribute-alias warning for SYSCALL_DEFINEx()"), which seems too invasive > to backport. Too invasive? Here's the diffstat: include/linux/compat.h | 8 +++++++- include/linux/syscalls.h | 4 ++++ 2 files changed, 11 insertions(+), 1 deletion(-) That seems almost trivial to backport. Did you try it and it caused other problems? Where ever possible, I always want to use the upstream commits. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html