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 <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/ia64/ia32/ia32_entry.S b/arch/ia64/ia32/ia32_entry.S
index a46f839..af9405c 100644
--- a/arch/ia64/ia32/ia32_entry.S
+++ b/arch/ia64/ia32/ia32_entry.S
@@ -240,7 +240,7 @@
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 1a86f84..784859c 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -356,40 +356,6 @@
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 7438e92..f61d6b0 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -253,7 +253,7 @@
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 b0fef4f..60997f1 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -265,7 +265,7 @@
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 303d2b6..03b9a01 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 72353f6..fe16649 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -65,7 +65,7 @@
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 62c706e..87cf5a7 100644
--- a/arch/s390/kernel/compat_wrapper.S
+++ b/arch/s390/kernel/compat_wrapper.S
@@ -252,7 +252,7 @@
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 5a0d76d..8ef8876 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -557,7 +557,7 @@
.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 6c0d7f6..efac92f 100644
--- a/arch/x86/ia32/sys_ia32.c
+++ b/arch/x86/ia32/sys_ia32.c
@@ -638,28 +638,6 @@
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 50ca486..1f7e625 100644
--- a/arch/x86/include/asm/ia32.h
+++ b/arch/x86/include/asm/ia32.h
@@ -129,13 +129,6 @@
} _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 ffb08be..72a6dcd 100644
--- a/arch/x86/include/asm/sys_ia32.h
+++ b/arch/x86/include/asm/sys_ia32.h
@@ -70,8 +70,6 @@
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 d0145ca..4e0db94 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -378,6 +378,34 @@
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 3fd2194..b880864 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -125,6 +125,13 @@
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 @@
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);