Commit Graph

9 Commits

Author SHA1 Message Date
Clement Calmels 1804dc6e14 /proc/self/maps doesn't display the real file offset
This addresses

	http://bugzilla.kernel.org/show_bug.cgi?id=11318

In function show_map (file: fs/proc/task_mmu.c), if vma->vm_pgoff > 2^20
than (vma->vm_pgoff << PAGE_SIZE) is greater than 2^32 (with PAGE_SIZE
equal to 4096 (i.e.  2^12).  The next seq_printf use an unsigned long for
the conversion of (vma->vm_pgoff << PAGE_SIZE), as a result the offset
value displayed in /proc/self/maps is truncated if the page offset is
greater than 2^20.

A test that shows this issue:

#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

#define PAGE_SIZE (getpagesize())

#if __i386__
#   define U64_STR "%llx"
#elif __x86_64
#   define U64_STR "%lx"
#else
#   error "Architecture Unsupported"
#endif

int main(int argc, char *argv[])
{
	int fd;
	char *addr;
	off64_t offset = 0x10000000;
	char *filename = "/dev/zero";

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
		perror("open");
		return 1;
	}

	offset *= 0x10;
	printf("offset = " U64_STR "\n", offset);

	addr = (char*)mmap64(NULL, PAGE_SIZE, PROT_READ, MAP_PRIVATE, fd,
			     offset);
	if ((void*)addr == MAP_FAILED) {
		perror("mmap64");
		return 1;
	}

	{
		FILE *fmaps;
		char *line = NULL;
		size_t len = 0;
		ssize_t read;
		size_t filename_len = strlen(filename);

		fmaps = fopen("/proc/self/maps", "r");
		if (!fmaps) {
			perror("fopen");
			return 1;
		}
		while ((read = getline(&line, &len, fmaps)) != -1) {
			if ((read > filename_len + 1)
			    && (strncmp(&line[read - filename_len - 1], filename, filename_len) == 0))
				printf("%s", line);
		}

		if (line)
			free(line);

		fclose(fmaps);
	}

	close(fd);
	return 0;
}

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Clement Calmels <cboulte@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 15:40:30 -07:00
Alexey Dobriyan 0d5c9f5f59 proc: switch to proc_create()
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
Jan Blunck c32c2f63a9 d_path: Make seq_path() use a struct path argument
seq_path() is always called with a dentry and a vfsmount from a struct path.
Make seq_path() take it directly as an argument.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:17:08 -08:00
Jan Engelhardt 03a44825be procfs: constify function pointer tables
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-By: David Howells <dhowells@redhat.com>
Acked-by: Bryan Wu <bryan.wu@analog.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 09:22:38 -08:00
Arjan van de Ven 00977a59b9 [PATCH] mark struct file_operations const 6
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00
Josef "Jeff" Sipek 2fddfeefee [PATCH] proc: change uses of f_{dentry, vfsmnt} to use f_path
Change all the uses of f_{dentry,vfsmnt} to f_path.{dentry,mnt} in the proc
filesystem code.

Signed-off-by: Josef "Jeff" Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:41 -08:00
David Howells dbf8685c8e [PATCH] NOMMU: Implement /proc/pid/maps for NOMMU
Implement /proc/pid/maps for NOMMU by reading the vm_area_list attached to
current->mm->context.vmlist.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-27 08:26:14 -07:00
David McCullough b65574fec5 [PATCH] output of /proc/maps on nommu systems is incomplete
Currently you do not get all the map entries on nommu systems because the
start function doesn't index into the list using the value of "pos".

Signed-off-by: David McCullough <davidm@snapgear.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-17 17:03:57 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00