Firstly, since the sys_* functions are internally used by our library routines, it is ok to let them preserve the 'long' return type of my_syscall<N> macros, that means not necessary to return pointer like their library routines do.
Secondly, in order to avoid the size inflating issues introduced by the sign extension, it is better to let __sysret() only accept integer input types, to do so, we must let all of the sys_* functions not return pointers.
There are only three sys_* functions which return pointer, let's make them return 'long' instead of pointer.
Link: https://lore.kernel.org/lkml/20230809221743.83107-1-falcon@tinylab.org/ Signed-off-by: Zhangjin Wu falcon@tinylab.org --- tools/include/nolibc/arch-s390.h | 4 ++-- tools/include/nolibc/sys.h | 16 ++++++++-------- 2 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h index 5d60fd43f883..6396c2a6bc3a 100644 --- a/tools/include/nolibc/arch-s390.h +++ b/tools/include/nolibc/arch-s390.h @@ -160,7 +160,7 @@ struct s390_mmap_arg_struct { };
static __attribute__((unused)) -void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, +long sys_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { struct s390_mmap_arg_struct args = { @@ -172,7 +172,7 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, .offset = (unsigned long)offset };
- return (void *)my_syscall1(__NR_mmap, &args); + return my_syscall1(__NR_mmap, &args); } #define sys_mmap sys_mmap
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 833d6c5e86dc..a28e7fbff448 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -74,9 +74,9 @@ long __sysret(unsigned long ret) */
static __attribute__((unused)) -void *sys_brk(void *addr) +long sys_brk(void *addr) { - return (void *)my_syscall1(__NR_brk, addr); + return my_syscall1(__NR_brk, addr); }
static __attribute__((unused)) @@ -89,12 +89,12 @@ static __attribute__((unused)) void *sbrk(intptr_t inc) { /* first call to find current end */ - void *ret = sys_brk(0); + void *ret = (void *)sys_brk(0);
- if (ret && sys_brk(ret + inc) == ret + inc) + if (ret && (void *)sys_brk(ret + inc) == ret + inc) return ret + inc;
- return (void *)__sysret(-ENOMEM); + return (void *)__sysret((long)-ENOMEM); }
@@ -658,7 +658,7 @@ int mknod(const char *path, mode_t mode, dev_t dev)
#ifndef sys_mmap static __attribute__((unused)) -void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, +long sys_mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { int n; @@ -670,7 +670,7 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, n = __NR_mmap; #endif
- return (void *)my_syscall6(n, addr, length, prot, flags, fd, offset); + return my_syscall6(n, addr, length, prot, flags, fd, offset); } #endif
@@ -682,7 +682,7 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, static __attribute__((unused)) void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) { - return (void *)__sysret((unsigned long)sys_mmap(addr, length, prot, flags, fd, offset)); + return (void *)__sysret(sys_mmap(addr, length, prot, flags, fd, offset)); }
static __attribute__((unused))