From: Arun Sharma <arun.sharma@intel.com>
Due to different structure alignment rules in the ABI between ia32 and
ia64, certain members of the dirent structure are not guaranteed to be 8
byte aligned on ia64. This requires a compat wrapper around these 32 bit
system calls. Other architectures may or may not have the problem,
depending on the alignment rules.
This was observed by running /emul/ia32-linux/bin/ls on 2.6.6 which produces
kernel mode unaligned faults.
Original patch by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Gordon Jin <gordon.jin@intel.com>
Signed-off-by: Arun Sharma <arun.sharma@intel.com>
---
25-akpm/arch/ia64/ia32/ia32_entry.S | 4
25-akpm/fs/compat.c | 255 ++++++++++++++++++++++++++++++++++++
2 files changed, 257 insertions(+), 2 deletions(-)
diff -puN arch/ia64/ia32/ia32_entry.S~sys-getdents64-needs-compat-wrapper arch/ia64/ia32/ia32_entry.S
--- 25/arch/ia64/ia32/ia32_entry.S~sys-getdents64-needs-compat-wrapper 2004-06-08 23:33:18.496748296 -0700
+++ 25-akpm/arch/ia64/ia32/ia32_entry.S 2004-06-08 23:33:18.504747080 -0700
@@ -349,7 +349,7 @@ ia32_syscall_table:
data8 sys_setfsuid /* 16-bit version */
data8 sys_setfsgid /* 16-bit version */
data8 sys_llseek /* 140 */
- data8 sys32_getdents
+ data8 compat_sys_getdents
data8 compat_sys_select
data8 sys_flock
data8 sys32_msync
@@ -428,7 +428,7 @@ ia32_syscall_table:
data8 sys_pivot_root
data8 sys_mincore
data8 sys_madvise
- data8 sys_getdents64 /* 220 */
+ data8 compat_sys_getdents64 /* 220 */
data8 compat_sys_fcntl64
data8 sys_ni_syscall /* reserved for TUX */
data8 sys_ni_syscall /* reserved for Security */
diff -puN fs/compat.c~sys-getdents64-needs-compat-wrapper fs/compat.c
--- 25/fs/compat.c~sys-getdents64-needs-compat-wrapper 2004-06-08 23:33:18.499747840 -0700
+++ 25-akpm/fs/compat.c 2004-06-08 23:40:18.895837920 -0700
@@ -34,6 +34,7 @@
#include <linux/syscalls.h>
#include <linux/ctype.h>
#include <linux/module.h>
+#include <linux/dirent.h>
#include <linux/dnotify.h>
#include <linux/highuid.h>
#include <linux/sunrpc/svc.h>
@@ -797,6 +798,260 @@ asmlinkage long compat_sys_mount(char __
return retval;
}
+#define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de)))
+#define COMPAT_ROUND_UP(x) (((x)+sizeof(compat_long_t)-1) & \
+ ~(sizeof(compat_long_t)-1))
+
+struct compat_old_linux_dirent {
+ compat_ulong_t d_ino;
+ compat_ulong_t d_offset;
+ unsigned short d_namlen;
+ char d_name[1];
+};
+
+struct compat_readdir_callback {
+ struct compat_old_linux_dirent __user *dirent;
+ int result;
+};
+
+static int compat_fillonedir(void *__buf, const char *name, int namlen,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct compat_readdir_callback *buf = __buf;
+ struct compat_old_linux_dirent __user *dirent;
+
+ if (buf->result)
+ return -EINVAL;
+ buf->result++;
+ dirent = buf->dirent;
+ if (!access_ok(VERIFY_WRITE, (unsigned long)dirent,
+ (unsigned long)(dirent->d_name + namlen + 1) -
+ (unsigned long)dirent))
+ goto efault;
+ if ( __put_user(ino, &dirent->d_ino) ||
+ __put_user(offset, &dirent->d_offset) ||
+ __put_user(namlen, &dirent->d_namlen) ||
+ __copy_to_user(dirent->d_name, name, namlen) ||
+ __put_user(0, dirent->d_name + namlen))
+ goto efault;
+ return 0;
+efault:
+ buf->result = -EFAULT;
+ return -EFAULT;
+}
+
+asmlinkage long compat_old_readdir(unsigned int fd,
+ struct compat_old_linux_dirent __user *dirent, unsigned int count)
+{
+ int error;
+ struct file *file;
+ struct compat_readdir_callback buf;
+
+ error = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+
+ buf.result = 0;
+ buf.dirent = dirent;
+
+ error = vfs_readdir(file, compat_fillonedir, &buf);
+ if (error >= 0)
+ error = buf.result;
+
+ fput(file);
+out:
+ return error;
+}
+
+struct compat_linux_dirent {
+ compat_ulong_t d_ino;
+ compat_ulong_t d_off;
+ unsigned short d_reclen;
+ char d_name[1];
+};
+
+struct compat_getdents_callback {
+ struct compat_linux_dirent __user *current_dir;
+ struct compat_linux_dirent __user *previous;
+ int count;
+ int error;
+};
+
+static int compat_filldir(void *__buf, const char *name, int namlen,
+ loff_t offset, ino_t ino, unsigned int d_type)
+{
+ struct compat_linux_dirent __user * dirent;
+ struct compat_getdents_callback *buf = __buf;
+ int reclen = COMPAT_ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);
+
+ buf->error = -EINVAL; /* only used if we fail.. */
+ if (reclen > buf->count)
+ return -EINVAL;
+ dirent = buf->previous;
+ if (dirent) {
+ if (__put_user(offset, &dirent->d_off))
+ goto efault;
+ }
+ dirent = buf->current_dir;
+ if (__put_user(ino, &dirent->d_ino))
+ goto efault;
+ if (__put_user(reclen, &dirent->d_reclen))
+ goto efault;
+ if (copy_to_user(dirent->d_name, name, namlen))
+ goto efault;
+ if (__put_user(0, dirent->d_name + namlen))
+ goto efault;
+ if (__put_user(d_type, (char __user *) dirent + reclen - 1))
+ goto efault;
+ buf->previous = dirent;
+ dirent = (void __user *)dirent + reclen;
+ buf->current_dir = dirent;
+ buf->count -= reclen;
+ return 0;
+efault:
+ buf->error = -EFAULT;
+ return -EFAULT;
+}
+
+asmlinkage long compat_sys_getdents(unsigned int fd,
+ struct compat_linux_dirent __user *dirent, unsigned int count)
+{
+ struct file * file;
+ struct compat_linux_dirent __user * lastdirent;
+ struct compat_getdents_callback buf;
+ int error;
+
+ error = -EFAULT;
+ if (!access_ok(VERIFY_WRITE, dirent, count))
+ goto out;
+
+ error = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+
+ buf.current_dir = dirent;
+ buf.previous = NULL;
+ buf.count = count;
+ buf.error = 0;
+
+ error = vfs_readdir(file, compat_filldir, &buf);
+ if (error < 0)
+ goto out_putf;
+ error = buf.error;
+ lastdirent = buf.previous;
+ if (lastdirent) {
+ if (put_user(file->f_pos, &lastdirent->d_off))
+ error = -EFAULT;
+ else
+ error = count - buf.count;
+ }
+
+out_putf:
+ fput(file);
+out:
+ return error;
+}
+
+#ifndef __ARCH_OMIT_COMPAT_SYS_GETDENTS64
+#define COMPAT_ROUND_UP64(x) (((x)+sizeof(u64)-1) & ~(sizeof(u64)-1))
+
+struct compat_getdents_callback64 {
+ struct linux_dirent64 __user *current_dir;
+ struct linux_dirent64 __user *previous;
+ int count;
+ int error;
+};
+
+static int compat_filldir64(void * __buf, const char * name, int namlen, loff_t offset,
+ ino_t ino, unsigned int d_type)
+{
+ struct linux_dirent64 __user *dirent;
+ struct compat_getdents_callback64 *buf = __buf;
+ int jj = NAME_OFFSET(dirent);
+ int reclen = COMPAT_ROUND_UP64(jj + namlen + 1);
+ u64 off;
+
+ buf->error = -EINVAL; /* only used if we fail.. */
+ if (reclen > buf->count)
+ return -EINVAL;
+ dirent = buf->previous;
+
+ if (dirent) {
+ if (__put_user(offset, (u32 __user *)&dirent->d_off))
+ goto efault;
+ if (__put_user(offset >> 32,
+ ((u32 __user *)&dirent->d_off) + 1))
+ goto efault;
+ }
+ dirent = buf->current_dir;
+ if ((__put_user(ino, (u32 __user *)&dirent->d_ino))
+ || (__put_user(ino >> 32, ((u32 __user *)&dirent->d_ino) + 1)))
+ goto efault;
+ off = 0;
+ if ((__put_user(off, (u32 __user *)&dirent->d_off))
+ || (__put_user(off >> 32, ((u32 __user *)&dirent->d_off) + 1)))
+ goto efault;
+ if (__put_user(reclen, &dirent->d_reclen))
+ goto efault;
+ if (__put_user(d_type, &dirent->d_type))
+ goto efault;
+ if (copy_to_user(dirent->d_name, name, namlen))
+ goto efault;
+ if (__put_user(0, dirent->d_name + namlen))
+ goto efault;
+ buf->previous = dirent;
+ dirent = (void __user *)dirent + reclen;
+ buf->current_dir = dirent;
+ buf->count -= reclen;
+ return 0;
+efault:
+ buf->error = -EFAULT;
+ return -EFAULT;
+}
+
+asmlinkage long compat_sys_getdents64(unsigned int fd,
+ struct linux_dirent64 __user * dirent, unsigned int count)
+{
+ struct file * file;
+ struct linux_dirent64 __user * lastdirent;
+ struct compat_getdents_callback64 buf;
+ int error;
+
+ error = -EFAULT;
+ if (!access_ok(VERIFY_WRITE, dirent, count))
+ goto out;
+
+ error = -EBADF;
+ file = fget(fd);
+ if (!file)
+ goto out;
+
+ buf.current_dir = dirent;
+ buf.previous = NULL;
+ buf.count = count;
+ buf.error = 0;
+
+ error = vfs_readdir(file, compat_filldir64, &buf);
+ if (error < 0)
+ goto out_putf;
+ error = buf.error;
+ lastdirent = buf.previous;
+ if (lastdirent) {
+ typeof(lastdirent->d_off) d_off = file->f_pos;
+ __put_user(d_off, (u32 __user *)&lastdirent->d_off);
+ __put_user(d_off >> 32, ((u32 __user *)&lastdirent->d_off) + 1);
+ error = count - buf.count;
+ }
+
+out_putf:
+ fput(file);
+out:
+ return error;
+}
+#endif /* ! __ARCH_OMIT_COMPAT_SYS_GETDENTS64 */
+
static ssize_t compat_do_readv_writev(int type, struct file *file,
const struct compat_iovec __user *uvector,
unsigned long nr_segs, loff_t *pos)
_