From 8f9c0119d7ba94c3ad13876acc240d7f12b6d8e1 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 19 Sep 2012 12:01:52 +0100 Subject: [PATCH] compat: fs: Generic compat_sys_sendfile implementation This function is used by sparc, powerpc and arm64 for compat support. The patch adds a generic implementation which calls do_sendfile() directly and avoids set_fs(). The sparc architecture has wrappers for the sign extensions while powerpc relies on the compiler to do the this. The patch adds wrappers for powerpc to handle the u32->int type conversion. compat_sys_sendfile64() can be replaced by a sys_sendfile() call since compat_loff_t has the same size as off_t on a 64-bit system. On powerpc, the patch also changes the 64-bit sendfile call from sys_sendile64 to sys_sendfile. Signed-off-by: Catalin Marinas Acked-by: David S. Miller Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Alexander Viro Cc: Andrew Morton Signed-off-by: Al Viro --- arch/powerpc/include/asm/systbl.h | 4 +-- arch/powerpc/include/asm/unistd.h | 1 + arch/powerpc/kernel/sys_ppc32.c | 45 +++++------------------------- arch/sparc/include/asm/unistd.h | 1 + arch/sparc/kernel/sys32.S | 2 +- arch/sparc/kernel/sys_sparc32.c | 46 ------------------------------- fs/compat.c | 22 +++++++++++++++ fs/read_write.c | 4 +-- fs/read_write.h | 2 ++ include/linux/compat.h | 3 ++ 10 files changed, 41 insertions(+), 89 deletions(-) diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h index 559ae1ee6706..840838769853 100644 --- a/arch/powerpc/include/asm/systbl.h +++ b/arch/powerpc/include/asm/systbl.h @@ -189,7 +189,7 @@ SYSCALL_SPU(getcwd) SYSCALL_SPU(capget) SYSCALL_SPU(capset) COMPAT_SYS(sigaltstack) -SYSX_SPU(sys_sendfile64,compat_sys_sendfile,sys_sendfile) +SYSX_SPU(sys_sendfile,compat_sys_sendfile_wrapper,sys_sendfile) SYSCALL(ni_syscall) SYSCALL(ni_syscall) PPC_SYS(vfork) @@ -229,7 +229,7 @@ COMPAT_SYS_SPU(sched_setaffinity) COMPAT_SYS_SPU(sched_getaffinity) SYSCALL(ni_syscall) SYSCALL(ni_syscall) -SYS32ONLY(sendfile64) +SYSX(sys_ni_syscall,compat_sys_sendfile64_wrapper,sys_sendfile64) COMPAT_SYS_SPU(io_setup) SYSCALL_SPU(io_destroy) COMPAT_SYS_SPU(io_getevents) diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h index bd377a368611..c683fa350add 100644 --- a/arch/powerpc/include/asm/unistd.h +++ b/arch/powerpc/include/asm/unistd.h @@ -419,6 +419,7 @@ #define __ARCH_WANT_COMPAT_SYS_TIME #define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND #define __ARCH_WANT_SYS_NEWFSTATAT +#define __ARCH_WANT_COMPAT_SYS_SENDFILE #endif /* diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c index 81c570633ead..abd1112da54f 100644 --- a/arch/powerpc/kernel/sys_ppc32.c +++ b/arch/powerpc/kernel/sys_ppc32.c @@ -143,48 +143,17 @@ long compat_sys_ipc(u32 call, u32 first, u32 second, u32 third, compat_uptr_t pt * proper conversion (sign extension) between the register representation of a signed int (msr in 32-bit mode) * and the register representation of a signed int (msr in 64-bit mode) is performed. */ -asmlinkage long compat_sys_sendfile(u32 out_fd, u32 in_fd, compat_off_t __user * offset, u32 count) +asmlinkage long compat_sys_sendfile_wrapper(u32 out_fd, u32 in_fd, + compat_off_t __user *offset, u32 count) { - mm_segment_t old_fs = get_fs(); - int ret; - off_t of; - off_t __user *up; - - if (offset && get_user(of, offset)) - return -EFAULT; - - /* The __user pointer cast is valid because of the set_fs() */ - set_fs(KERNEL_DS); - up = offset ? (off_t __user *) &of : NULL; - ret = sys_sendfile((int)out_fd, (int)in_fd, up, count); - set_fs(old_fs); - - if (offset && put_user(of, offset)) - return -EFAULT; - - return ret; + return compat_sys_sendfile((int)out_fd, (int)in_fd, offset, count); } -asmlinkage int compat_sys_sendfile64(int out_fd, int in_fd, compat_loff_t __user *offset, s32 count) +asmlinkage long compat_sys_sendfile64_wrapper(u32 out_fd, u32 in_fd, + compat_loff_t __user *offset, u32 count) { - mm_segment_t old_fs = get_fs(); - int ret; - loff_t lof; - loff_t __user *up; - - if (offset && get_user(lof, offset)) - return -EFAULT; - - /* The __user pointer cast is valid because of the set_fs() */ - set_fs(KERNEL_DS); - up = offset ? (loff_t __user *) &lof : NULL; - ret = sys_sendfile64(out_fd, in_fd, up, count); - set_fs(old_fs); - - if (offset && put_user(lof, offset)) - return -EFAULT; - - return ret; + return sys_sendfile((int)out_fd, (int)in_fd, + (off_t __user *)offset, count); } long compat_sys_execve(unsigned long a0, unsigned long a1, unsigned long a2, diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h index fb2693464807..d9a677c51926 100644 --- a/arch/sparc/include/asm/unistd.h +++ b/arch/sparc/include/asm/unistd.h @@ -447,6 +447,7 @@ #else #define __ARCH_WANT_COMPAT_SYS_TIME #define __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND +#define __ARCH_WANT_COMPAT_SYS_SENDFILE #endif /* diff --git a/arch/sparc/kernel/sys32.S b/arch/sparc/kernel/sys32.S index d97f3eb72e06..44025f4ba41f 100644 --- a/arch/sparc/kernel/sys32.S +++ b/arch/sparc/kernel/sys32.S @@ -90,7 +90,7 @@ SIGN1(sys32_mkdir, sys_mkdir, %o1) SIGN3(sys32_futex, compat_sys_futex, %o1, %o2, %o5) SIGN1(sys32_sysfs, compat_sys_sysfs, %o0) SIGN2(sys32_sendfile, compat_sys_sendfile, %o0, %o1) -SIGN2(sys32_sendfile64, compat_sys_sendfile64, %o0, %o1) +SIGN2(sys32_sendfile64, sys_sendfile, %o0, %o1) SIGN1(sys32_prctl, sys_prctl, %o0) SIGN1(sys32_sched_rr_get_interval, compat_sys_sched_rr_get_interval, %o0) SIGN2(sys32_waitpid, sys_waitpid, %o0, %o2) diff --git a/arch/sparc/kernel/sys_sparc32.c b/arch/sparc/kernel/sys_sparc32.c index f7392336961f..d862499eb01c 100644 --- a/arch/sparc/kernel/sys_sparc32.c +++ b/arch/sparc/kernel/sys_sparc32.c @@ -506,52 +506,6 @@ long compat_sys_fadvise64_64(int fd, advice); } -asmlinkage long compat_sys_sendfile(int out_fd, int in_fd, - compat_off_t __user *offset, - compat_size_t count) -{ - mm_segment_t old_fs = get_fs(); - int ret; - off_t of; - - if (offset && get_user(of, offset)) - return -EFAULT; - - set_fs(KERNEL_DS); - ret = sys_sendfile(out_fd, in_fd, - offset ? (off_t __user *) &of : NULL, - count); - set_fs(old_fs); - - if (offset && put_user(of, offset)) - return -EFAULT; - - return ret; -} - -asmlinkage long compat_sys_sendfile64(int out_fd, int in_fd, - compat_loff_t __user *offset, - compat_size_t count) -{ - mm_segment_t old_fs = get_fs(); - int ret; - loff_t lof; - - if (offset && get_user(lof, offset)) - return -EFAULT; - - set_fs(KERNEL_DS); - ret = sys_sendfile64(out_fd, in_fd, - offset ? (loff_t __user *) &lof : NULL, - count); - set_fs(old_fs); - - if (offset && put_user(lof, offset)) - return -EFAULT; - - return ret; -} - /* This is just a version for 32-bit applications which does * not force O_LARGEFILE on. */ diff --git a/fs/compat.c b/fs/compat.c index d72d51e19025..b7a24d0ca30d 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -1792,3 +1792,25 @@ compat_sys_open_by_handle_at(int mountdirfd, return do_handle_open(mountdirfd, handle, flags); } #endif + +#ifdef __ARCH_WANT_COMPAT_SYS_SENDFILE +asmlinkage long compat_sys_sendfile(int out_fd, int in_fd, + compat_off_t __user *offset, compat_size_t count) +{ + loff_t pos; + off_t off; + ssize_t ret; + + if (offset) { + if (unlikely(get_user(off, offset))) + return -EFAULT; + pos = off; + ret = do_sendfile(out_fd, in_fd, &pos, count, MAX_NON_LFS); + if (unlikely(put_user(pos, offset))) + return -EFAULT; + return ret; + } + + return do_sendfile(out_fd, in_fd, NULL, count, 0); +} +#endif /* __ARCH_WANT_COMPAT_SYS_SENDFILE */ diff --git a/fs/read_write.c b/fs/read_write.c index 28b38279a219..d06534857e9e 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -862,8 +862,8 @@ SYSCALL_DEFINE5(pwritev, unsigned long, fd, const struct iovec __user *, vec, return ret; } -static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, - size_t count, loff_t max) +ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, size_t count, + loff_t max) { struct fd in, out; struct inode *in_inode, *out_inode; diff --git a/fs/read_write.h b/fs/read_write.h index d07b954c6e0c..d3e00ef67420 100644 --- a/fs/read_write.h +++ b/fs/read_write.h @@ -12,3 +12,5 @@ ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov, unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn); ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov, unsigned long nr_segs, loff_t *ppos, io_fn_t fn); +ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, size_t count, + loff_t max); diff --git a/include/linux/compat.h b/include/linux/compat.h index 09b28b7369d7..fd4e29956d1c 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -590,6 +590,9 @@ asmlinkage ssize_t compat_sys_process_vm_writev(compat_pid_t pid, unsigned long liovcnt, const struct compat_iovec __user *rvec, unsigned long riovcnt, unsigned long flags); +asmlinkage long compat_sys_sendfile(int out_fd, int in_fd, + compat_off_t __user *offset, compat_size_t count); + #else #define is_compat_task() (0) -- 2.30.2