From 2b1c6bd77d4e6a727ffac8630cd154b2144b751a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 28 Nov 2008 10:09:09 +0100 Subject: [PATCH] generic compat_sys_ustat Due to a different size of ino_t ustat needs a compat handler, but currently only x86 and mips provide one. Add a generic compat_sys_ustat and switch all architectures over to it. Instead of doing various user copy hacks compat_sys_ustat just reimplements sys_ustat as it's trivial. This was suggested by Arnd Bergmann. Found by Eric Sandeen when running xfstests/017 on ppc64, which causes stack smashing warnings on RHEL/Fedora due to the too large amount of data writen by the syscall. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- arch/ia64/ia32/ia32_entry.S | 2 +- arch/mips/kernel/linux32.c | 34 ------------------------------ arch/mips/kernel/scall64-n32.S | 2 +- arch/mips/kernel/scall64-o32.S | 2 +- arch/parisc/kernel/syscall_table.S | 2 +- arch/powerpc/include/asm/systbl.h | 2 +- arch/s390/kernel/compat_wrapper.S | 2 +- arch/x86/ia32/ia32entry.S | 2 +- arch/x86/ia32/sys_ia32.c | 22 ------------------- arch/x86/include/asm/ia32.h | 7 ------ arch/x86/include/asm/sys_ia32.h | 2 -- fs/compat.c | 28 ++++++++++++++++++++++++ include/linux/compat.h | 8 +++++++ 13 files changed, 43 insertions(+), 72 deletions(-) diff --git a/arch/ia64/ia32/ia32_entry.S b/arch/ia64/ia32/ia32_entry.S index a46f8395e9a..af9405cd70e 100644 --- a/arch/ia64/ia32/ia32_entry.S +++ b/arch/ia64/ia32/ia32_entry.S @@ -240,7 +240,7 @@ ia32_syscall_table: data8 sys_ni_syscall data8 sys_umask /* 60 */ data8 sys_chroot - data8 sys_ustat + data8 compat_sys_ustat data8 sys_dup2 data8 sys_getppid data8 sys_getpgrp /* 65 */ diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c index 1a86f84fa94..784859cedef 100644 --- a/arch/mips/kernel/linux32.c +++ b/arch/mips/kernel/linux32.c @@ -356,40 +356,6 @@ SYSCALL_DEFINE1(32_personality, unsigned long, personality) return ret; } -/* ustat compatibility */ -struct ustat32 { - compat_daddr_t f_tfree; - compat_ino_t f_tinode; - char f_fname[6]; - char f_fpack[6]; -}; - -extern asmlinkage long sys_ustat(dev_t dev, struct ustat __user * ubuf); - -SYSCALL_DEFINE2(32_ustat, dev_t, dev, struct ustat32 __user *, ubuf32) -{ - int err; - struct ustat tmp; - struct ustat32 tmp32; - mm_segment_t old_fs = get_fs(); - - set_fs(KERNEL_DS); - err = sys_ustat(dev, (struct ustat __user *)&tmp); - set_fs(old_fs); - - if (err) - goto out; - - memset(&tmp32, 0, sizeof(struct ustat32)); - tmp32.f_tfree = tmp.f_tfree; - tmp32.f_tinode = tmp.f_tinode; - - err = copy_to_user(ubuf32, &tmp32, sizeof(struct ustat32)) ? -EFAULT : 0; - -out: - return err; -} - SYSCALL_DEFINE4(32_sendfile, long, out_fd, long, in_fd, compat_off_t __user *, offset, s32, count) { diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S index 7438e92f8a0..f61d6b0e573 100644 --- a/arch/mips/kernel/scall64-n32.S +++ b/arch/mips/kernel/scall64-n32.S @@ -253,7 +253,7 @@ EXPORT(sysn32_call_table) PTR compat_sys_utime /* 6130 */ PTR sys_mknod PTR sys_32_personality - PTR sys_32_ustat + PTR compat_sys_ustat PTR compat_sys_statfs PTR compat_sys_fstatfs /* 6135 */ PTR sys_sysfs diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S index b0fef4ff982..60997f1f69d 100644 --- a/arch/mips/kernel/scall64-o32.S +++ b/arch/mips/kernel/scall64-o32.S @@ -265,7 +265,7 @@ sys_call_table: PTR sys_olduname PTR sys_umask /* 4060 */ PTR sys_chroot - PTR sys_32_ustat + PTR compat_sys_ustat PTR sys_dup2 PTR sys_getppid PTR sys_getpgrp /* 4065 */ diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S index 303d2b647e4..03b9a01bc16 100644 --- a/arch/parisc/kernel/syscall_table.S +++ b/arch/parisc/kernel/syscall_table.S @@ -130,7 +130,7 @@ ENTRY_OURS(newuname) ENTRY_SAME(umask) /* 60 */ ENTRY_SAME(chroot) - ENTRY_SAME(ustat) + ENTRY_COMP(ustat) ENTRY_SAME(dup2) ENTRY_SAME(getppid) ENTRY_SAME(getpgrp) /* 65 */ diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h index 72353f6070a..fe166491e9d 100644 --- a/arch/powerpc/include/asm/systbl.h +++ b/arch/powerpc/include/asm/systbl.h @@ -65,7 +65,7 @@ SYSCALL(ni_syscall) SYSX(sys_ni_syscall,sys_olduname, sys_olduname) COMPAT_SYS_SPU(umask) SYSCALL_SPU(chroot) -SYSCALL(ustat) +COMPAT_SYS(ustat) SYSCALL_SPU(dup2) SYSCALL_SPU(getppid) SYSCALL_SPU(getpgrp) diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S index 62c706eb0de..87cf5a79a35 100644 --- a/arch/s390/kernel/compat_wrapper.S +++ b/arch/s390/kernel/compat_wrapper.S @@ -252,7 +252,7 @@ sys32_chroot_wrapper: sys32_ustat_wrapper: llgfr %r2,%r2 # dev_t llgtr %r3,%r3 # struct ustat * - jg sys_ustat + jg compat_sys_ustat .globl sys32_dup2_wrapper sys32_dup2_wrapper: diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index 5a0d76dc56a..8ef8876666b 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -557,7 +557,7 @@ ia32_sys_call_table: .quad sys32_olduname .quad sys_umask /* 60 */ .quad sys_chroot - .quad sys32_ustat + .quad compat_sys_ustat .quad sys_dup2 .quad sys_getppid .quad sys_getpgrp /* 65 */ diff --git a/arch/x86/ia32/sys_ia32.c b/arch/x86/ia32/sys_ia32.c index 6c0d7f6231a..efac92fd1ef 100644 --- a/arch/x86/ia32/sys_ia32.c +++ b/arch/x86/ia32/sys_ia32.c @@ -638,28 +638,6 @@ long sys32_uname(struct old_utsname __user *name) return err ? -EFAULT : 0; } -long sys32_ustat(unsigned dev, struct ustat32 __user *u32p) -{ - struct ustat u; - mm_segment_t seg; - int ret; - - seg = get_fs(); - set_fs(KERNEL_DS); - ret = sys_ustat(dev, (struct ustat __user *)&u); - set_fs(seg); - if (ret < 0) - return ret; - - if (!access_ok(VERIFY_WRITE, u32p, sizeof(struct ustat32)) || - __put_user((__u32) u.f_tfree, &u32p->f_tfree) || - __put_user((__u32) u.f_tinode, &u32p->f_tfree) || - __copy_to_user(&u32p->f_fname, u.f_fname, sizeof(u.f_fname)) || - __copy_to_user(&u32p->f_fpack, u.f_fpack, sizeof(u.f_fpack))) - ret = -EFAULT; - return ret; -} - asmlinkage long sys32_execve(char __user *name, compat_uptr_t __user *argv, compat_uptr_t __user *envp, struct pt_regs *regs) { diff --git a/arch/x86/include/asm/ia32.h b/arch/x86/include/asm/ia32.h index 50ca486fd88..1f7e6251728 100644 --- a/arch/x86/include/asm/ia32.h +++ b/arch/x86/include/asm/ia32.h @@ -129,13 +129,6 @@ typedef struct compat_siginfo { } _sifields; } compat_siginfo_t; -struct ustat32 { - __u32 f_tfree; - compat_ino_t f_tinode; - char f_fname[6]; - char f_fpack[6]; -}; - #define IA32_STACK_TOP IA32_PAGE_OFFSET #ifdef __KERNEL__ diff --git a/arch/x86/include/asm/sys_ia32.h b/arch/x86/include/asm/sys_ia32.h index ffb08be2a53..72a6dcd1299 100644 --- a/arch/x86/include/asm/sys_ia32.h +++ b/arch/x86/include/asm/sys_ia32.h @@ -70,8 +70,6 @@ struct old_utsname; asmlinkage long sys32_olduname(struct oldold_utsname __user *); long sys32_uname(struct old_utsname __user *); -long sys32_ustat(unsigned, struct ustat32 __user *); - asmlinkage long sys32_execve(char __user *, compat_uptr_t __user *, compat_uptr_t __user *, struct pt_regs *); asmlinkage long sys32_clone(unsigned int, unsigned int, struct pt_regs *); diff --git a/fs/compat.c b/fs/compat.c index d0145ca2757..4e0db94b535 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -378,6 +378,34 @@ out: return error; } +/* + * This is a copy of sys_ustat, just dealing with a structure layout. + * Given how simple this syscall is that apporach is more maintainable + * than the various conversion hacks. + */ +asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u) +{ + struct super_block *sb; + struct compat_ustat tmp; + struct kstatfs sbuf; + int err; + + sb = user_get_super(new_decode_dev(dev)); + if (!sb) + return -EINVAL; + err = vfs_statfs(sb->s_root, &sbuf); + drop_super(sb); + if (err) + return err; + + memset(&tmp, 0, sizeof(struct compat_ustat)); + tmp.f_tfree = sbuf.f_bfree; + tmp.f_tinode = sbuf.f_ffree; + if (copy_to_user(u, &tmp, sizeof(struct compat_ustat))) + return -EFAULT; + return 0; +} + static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) { if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || diff --git a/include/linux/compat.h b/include/linux/compat.h index 3fd2194ff57..b880864672d 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -125,6 +125,13 @@ struct compat_dirent { char d_name[256]; }; +struct compat_ustat { + compat_daddr_t f_tfree; + compat_ino_t f_tinode; + char f_fname[6]; + char f_fpack[6]; +}; + typedef union compat_sigval { compat_int_t sival_int; compat_uptr_t sival_ptr; @@ -178,6 +185,7 @@ long compat_sys_semtimedop(int semid, struct sembuf __user *tsems, unsigned nsems, const struct compat_timespec __user *timeout); asmlinkage long compat_sys_keyctl(u32 option, u32 arg2, u32 arg3, u32 arg4, u32 arg5); +asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u32); asmlinkage ssize_t compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec, unsigned long vlen); -- 2.41.1