Revision 737449236240e30a7bbe99f4d5586b8ed1416763 authored by Mel Gorman on 31 July 2012, 23:45:20 UTC, committed by Linus Torvalds on 01 August 2012, 01:42:48 UTC
Commit b3a27d ("swap: Add swap slot free callback to block_device_operations") dereferences p->bdev->bd_disk but this is a NULL dereference if using swap-over-NFS. This patch checks SWP_BLKDEV on the swap_info_struct before dereferencing. With reference to this callback, Christoph Hellwig stated "Please just remove the callback entirely. It has no user outside the staging tree and was added clearly against the rules for that staging tree". This would also be my preference but there was not an obvious way of keeping zram in staging/ happy. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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binfmt_som.c
/*
* linux/fs/binfmt_som.c
*
* These are the functions used to load SOM format executables as used
* by HP-UX.
*
* Copyright 1999 Matthew Wilcox <willy@bofh.ai>
* based on binfmt_elf which is
* Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/binfmts.h>
#include <linux/som.h>
#include <linux/string.h>
#include <linux/file.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/shm.h>
#include <linux/personality.h>
#include <linux/init.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <linux/elf.h>
static int load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs);
static int load_som_library(struct file *);
/*
* If we don't support core dumping, then supply a NULL so we
* don't even try.
*/
#if 0
static int som_core_dump(struct coredump_params *cprm);
#else
#define som_core_dump NULL
#endif
#define SOM_PAGESTART(_v) ((_v) & ~(unsigned long)(SOM_PAGESIZE-1))
#define SOM_PAGEOFFSET(_v) ((_v) & (SOM_PAGESIZE-1))
#define SOM_PAGEALIGN(_v) (((_v) + SOM_PAGESIZE - 1) & ~(SOM_PAGESIZE - 1))
static struct linux_binfmt som_format = {
.module = THIS_MODULE,
.load_binary = load_som_binary,
.load_shlib = load_som_library,
.core_dump = som_core_dump,
.min_coredump = SOM_PAGESIZE
};
/*
* create_som_tables() parses the env- and arg-strings in new user
* memory and creates the pointer tables from them, and puts their
* addresses on the "stack", returning the new stack pointer value.
*/
static void create_som_tables(struct linux_binprm *bprm)
{
char **argv, **envp;
int argc = bprm->argc;
int envc = bprm->envc;
unsigned long p;
unsigned long *sp;
/* Word-align the stack pointer */
sp = (unsigned long *)((bprm->p + 3) & ~3);
envp = (char **) sp;
sp += envc + 1;
argv = (char **) sp;
sp += argc + 1;
__put_user((unsigned long) envp,++sp);
__put_user((unsigned long) argv,++sp);
__put_user(argc, ++sp);
bprm->p = (unsigned long) sp;
p = current->mm->arg_start;
while (argc-- > 0) {
__put_user((char *)p,argv++);
p += strlen_user((char *)p);
}
__put_user(NULL, argv);
current->mm->arg_end = current->mm->env_start = p;
while (envc-- > 0) {
__put_user((char *)p,envp++);
p += strlen_user((char *)p);
}
__put_user(NULL, envp);
current->mm->env_end = p;
}
static int check_som_header(struct som_hdr *som_ex)
{
int *buf = (int *)som_ex;
int i, ck;
if (som_ex->system_id != SOM_SID_PARISC_1_0 &&
som_ex->system_id != SOM_SID_PARISC_1_1 &&
som_ex->system_id != SOM_SID_PARISC_2_0)
return -ENOEXEC;
if (som_ex->a_magic != SOM_EXEC_NONSHARE &&
som_ex->a_magic != SOM_EXEC_SHARE &&
som_ex->a_magic != SOM_EXEC_DEMAND)
return -ENOEXEC;
if (som_ex->version_id != SOM_ID_OLD &&
som_ex->version_id != SOM_ID_NEW)
return -ENOEXEC;
ck = 0;
for (i=0; i<32; i++)
ck ^= buf[i];
if (ck != 0)
return -ENOEXEC;
return 0;
}
static int map_som_binary(struct file *file,
const struct som_exec_auxhdr *hpuxhdr)
{
unsigned long code_start, code_size, data_start, data_size;
unsigned long bss_start, som_brk;
int retval;
int prot = PROT_READ | PROT_EXEC;
int flags = MAP_FIXED|MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE;
mm_segment_t old_fs = get_fs();
set_fs(get_ds());
code_start = SOM_PAGESTART(hpuxhdr->exec_tmem);
code_size = SOM_PAGEALIGN(hpuxhdr->exec_tsize);
current->mm->start_code = code_start;
current->mm->end_code = code_start + code_size;
retval = vm_mmap(file, code_start, code_size, prot,
flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
if (retval < 0 && retval > -1024)
goto out;
data_start = SOM_PAGESTART(hpuxhdr->exec_dmem);
data_size = SOM_PAGEALIGN(hpuxhdr->exec_dsize);
current->mm->start_data = data_start;
current->mm->end_data = bss_start = data_start + data_size;
retval = vm_mmap(file, data_start, data_size,
prot | PROT_WRITE, flags,
SOM_PAGESTART(hpuxhdr->exec_dfile));
if (retval < 0 && retval > -1024)
goto out;
som_brk = bss_start + SOM_PAGEALIGN(hpuxhdr->exec_bsize);
current->mm->start_brk = current->mm->brk = som_brk;
retval = vm_mmap(NULL, bss_start, som_brk - bss_start,
prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE, 0);
if (retval > 0 || retval < -1024)
retval = 0;
out:
set_fs(old_fs);
return retval;
}
/*
* These are the functions used to load SOM executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
static int
load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
{
int retval;
unsigned int size;
unsigned long som_entry;
struct som_hdr *som_ex;
struct som_exec_auxhdr *hpuxhdr;
/* Get the exec-header */
som_ex = (struct som_hdr *) bprm->buf;
retval = check_som_header(som_ex);
if (retval != 0)
goto out;
/* Now read in the auxiliary header information */
retval = -ENOMEM;
size = som_ex->aux_header_size;
if (size > SOM_PAGESIZE)
goto out;
hpuxhdr = kmalloc(size, GFP_KERNEL);
if (!hpuxhdr)
goto out;
retval = kernel_read(bprm->file, som_ex->aux_header_location,
(char *) hpuxhdr, size);
if (retval != size) {
if (retval >= 0)
retval = -EIO;
goto out_free;
}
/* Flush all traces of the currently running executable */
retval = flush_old_exec(bprm);
if (retval)
goto out_free;
/* OK, This is the point of no return */
current->personality = PER_HPUX;
setup_new_exec(bprm);
/* Set the task size for HP-UX processes such that
* the gateway page is outside the address space.
* This can be fixed later, but for now, this is much
* easier.
*/
current->thread.task_size = 0xc0000000;
/* Set map base to allow enough room for hp-ux heap growth */
current->thread.map_base = 0x80000000;
retval = map_som_binary(bprm->file, hpuxhdr);
if (retval < 0)
goto out_free;
som_entry = hpuxhdr->exec_entry;
kfree(hpuxhdr);
set_binfmt(&som_format);
install_exec_creds(bprm);
setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
create_som_tables(bprm);
current->mm->start_stack = bprm->p;
#if 0
printk("(start_brk) %08lx\n" , (unsigned long) current->mm->start_brk);
printk("(end_code) %08lx\n" , (unsigned long) current->mm->end_code);
printk("(start_code) %08lx\n" , (unsigned long) current->mm->start_code);
printk("(end_data) %08lx\n" , (unsigned long) current->mm->end_data);
printk("(start_stack) %08lx\n" , (unsigned long) current->mm->start_stack);
printk("(brk) %08lx\n" , (unsigned long) current->mm->brk);
#endif
map_hpux_gateway_page(current,current->mm);
start_thread_som(regs, som_entry, bprm->p);
return 0;
/* error cleanup */
out_free:
kfree(hpuxhdr);
out:
return retval;
}
static int load_som_library(struct file *f)
{
/* No lib support in SOM yet. gizza chance.. */
return -ENOEXEC;
}
/* Install the SOM loader.
* N.B. We *rely* on the table being the right size with the
* right number of free slots...
*/
static int __init init_som_binfmt(void)
{
register_binfmt(&som_format);
return 0;
}
static void __exit exit_som_binfmt(void)
{
/* Remove the SOM loader. */
unregister_binfmt(&som_format);
}
core_initcall(init_som_binfmt);
module_exit(exit_som_binfmt);
MODULE_LICENSE("GPL");
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