Commit cff2b760 authored by Ulrich Drepper's avatar Ulrich Drepper Committed by Linus Torvalds
Browse files

[PATCH] fstatat64 support 



The *at patches introduced fstatat and, due to inusfficient research, I
used the newfstat functions generally as the guideline.  The result is that
on 32-bit platforms we don't have all the information needed to implement
fstatat64.

This patch modifies the code to pass up 64-bit information if
__ARCH_WANT_STAT64 is defined.  I renamed the syscall entry point to make
this clear.  Other archs will continue to use the existing code.  On x86-64
the compat code is implemented using a new sys32_ function.  this is what
is done for the other stat syscalls as well.

This patch might break some other archs (those which define
__ARCH_WANT_STAT64 and which already wired up the syscall).  Yet others
might need changes to accomodate the compatibility mode.  I really don't
want to do that work because all this stat handling is a mess (more so in
glibc, but the kernel is also affected).  It should be done by the arch
maintainers.  I'll provide some stand-alone test shortly.  Those who are
eager could compile glibc and run 'make check' (no installation needed).

The patch below has been tested on x86 and x86-64.

Signed-off-by: default avatarUlrich Drepper <drepper@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 25bf368b

arch/i386/kernel/syscall_table.S

+1 −1
Original line number Diff line number Diff line
@@ -299,7 +299,7 @@ ENTRY(sys_call_table) 
	.long sys_mknodat

	.long sys_fchownat

	.long sys_futimesat

	.long sys_newfstatat		/* 300 */

	.long sys_fstatat64		/* 300 */

	.long sys_unlinkat

	.long sys_renameat

	.long sys_linkat

arch/x86_64/ia32/ia32entry.S

+1 −1
Original line number Diff line number Diff line
@@ -677,7 +677,7 @@ ia32_sys_call_table: 
	.quad sys_mknodat

	.quad sys_fchownat

	.quad compat_sys_futimesat

	.quad compat_sys_newfstatat	/* 300 */

	.quad sys32_fstatat		/* 300 */

	.quad sys_unlinkat

	.quad sys_renameat

	.quad sys_linkat

arch/x86_64/ia32/sys_ia32.c

+22 −0
Original line number Diff line number Diff line
@@ -180,6 +180,28 @@ sys32_fstat64(unsigned int fd, struct stat64 __user *statbuf) 
	return ret;

}



asmlinkage long

sys32_fstatat(unsigned int dfd, char __user *filename,

	      struct stat64 __user* statbuf, int flag)

{

	struct kstat stat;

	int error = -EINVAL;



	if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)

		goto out;



	if (flag & AT_SYMLINK_NOFOLLOW)

		error = vfs_lstat_fd(dfd, filename, &stat);

	else

		error = vfs_stat_fd(dfd, filename, &stat);



	if (!error)

		error = cp_stat64(statbuf, &stat);



out:

	return error;

}



/*

 * Linux/i386 didn't use to be able to handle more than

 * 4 system call parameters, so these system calls used a memory

fs/stat.c

+22 −0
Original line number Diff line number Diff line
@@ -261,6 +261,7 @@ asmlinkage long sys_newlstat(char __user *filename, struct stat __user *statbuf) 
	return error;

}



#ifndef __ARCH_WANT_STAT64

asmlinkage long sys_newfstatat(int dfd, char __user *filename,

				struct stat __user *statbuf, int flag)

{
@@ -281,6 +282,7 @@ asmlinkage long sys_newfstatat(int dfd, char __user *filename, 
out:

	return error;

}

#endif



asmlinkage long sys_newfstat(unsigned int fd, struct stat __user *statbuf)

{
@@ -395,6 +397,26 @@ asmlinkage long sys_fstat64(unsigned long fd, struct stat64 __user * statbuf) 
	return error;

}



asmlinkage long sys_fstatat64(int dfd, char __user *filename,

			       struct stat64 __user *statbuf, int flag)

{

	struct kstat stat;

	int error = -EINVAL;



	if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)

		goto out;



	if (flag & AT_SYMLINK_NOFOLLOW)

		error = vfs_lstat_fd(dfd, filename, &stat);

	else

		error = vfs_stat_fd(dfd, filename, &stat);



	if (!error)

		error = cp_new_stat64(&stat, statbuf);



out:

	return error;

}

#endif /* __ARCH_WANT_STAT64 */



void inode_add_bytes(struct inode *inode, loff_t bytes)

include/asm-i386/unistd.h

+1 −1
Original line number Diff line number Diff line
@@ -305,7 +305,7 @@ 
#define __NR_mknodat		297

#define __NR_fchownat		298

#define __NR_futimesat		299

#define __NR_newfstatat		300

#define __NR_fstatat64		300

#define __NR_unlinkat		301

#define __NR_renameat		302

#define __NR_linkat		303

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