lkml.org 
[lkml]   [2011]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 2/5] exec: introduce "bool compat" argument
No functional changes, preparation to simplify the review.

And the new (and currently unused) "bool compat" argument to
get_arg_ptr(), count(), and copy_strings().

Add this argument to do_execve() as well, and rename it to
do_execve_common().

Reintroduce do_execve() as a trivial wrapper() on top of
do_execve_common(compat => false).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
fs/exec.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
--- 38/fs/exec.c~2_is_compat_arg 2011-02-25 18:04:50.000000000 +0100
+++ 38/fs/exec.c 2011-02-25 18:05:05.000000000 +0100
@@ -396,7 +396,7 @@ err:
}

static const char __user *
-get_arg_ptr(const char __user * const __user *argv, int argc)
+get_arg_ptr(const char __user * const __user *argv, int argc, bool compat)
{
const char __user *ptr;

@@ -409,13 +409,13 @@ get_arg_ptr(const char __user * const __
/*
* count() counts the number of strings in array ARGV.
*/
-static int count(const char __user * const __user * argv, int max)
+static int count(const char __user * const __user *argv, int max, bool compat)
{
int i = 0;

if (argv != NULL) {
for (;;) {
- const char __user *p = get_arg_ptr(argv, i);
+ const char __user *p = get_arg_ptr(argv, i, compat);

if (!p)
break;
@@ -440,7 +440,7 @@ static int count(const char __user * con
* ensures the destination page is created and not swapped out.
*/
static int copy_strings(int argc, const char __user *const __user *argv,
- struct linux_binprm *bprm)
+ struct linux_binprm *bprm, bool compat)
{
struct page *kmapped_page = NULL;
char *kaddr = NULL;
@@ -453,7 +453,7 @@ static int copy_strings(int argc, const
unsigned long pos;

ret = -EFAULT;
- str = get_arg_ptr(argv, argc);
+ str = get_arg_ptr(argv, argc, compat);
if (IS_ERR(str))
goto out;

@@ -536,7 +536,8 @@ int copy_strings_kernel(int argc, const
int r;
mm_segment_t oldfs = get_fs();
set_fs(KERNEL_DS);
- r = copy_strings(argc, (const char __user *const __user *)argv, bprm);
+ r = copy_strings(argc, (const char __user *const __user *)argv,
+ bprm, false);
set_fs(oldfs);
return r;
}
@@ -1387,10 +1388,10 @@ EXPORT_SYMBOL(search_binary_handler);
/*
* sys_execve() executes a new program.
*/
-int do_execve(const char * filename,
+static int do_execve_common(const char *filename,
const char __user *const __user *argv,
const char __user *const __user *envp,
- struct pt_regs * regs)
+ struct pt_regs *regs, bool compat)
{
struct linux_binprm *bprm;
struct file *file;
@@ -1432,11 +1433,11 @@ int do_execve(const char * filename,
if (retval)
goto out_file;

- bprm->argc = count(argv, MAX_ARG_STRINGS);
+ bprm->argc = count(argv, MAX_ARG_STRINGS, compat);
if ((retval = bprm->argc) < 0)
goto out;

- bprm->envc = count(envp, MAX_ARG_STRINGS);
+ bprm->envc = count(envp, MAX_ARG_STRINGS, compat);
if ((retval = bprm->envc) < 0)
goto out;

@@ -1449,11 +1450,11 @@ int do_execve(const char * filename,
goto out;

bprm->exec = bprm->p;
- retval = copy_strings(bprm->envc, envp, bprm);
+ retval = copy_strings(bprm->envc, envp, bprm, compat);
if (retval < 0)
goto out;

- retval = copy_strings(bprm->argc, argv, bprm);
+ retval = copy_strings(bprm->argc, argv, bprm, compat);
if (retval < 0)
goto out;

@@ -1497,6 +1498,14 @@ out_ret:
return retval;
}

+int do_execve(const char *filename,
+ const char __user *const __user *argv,
+ const char __user *const __user *envp,
+ struct pt_regs *regs)
+{
+ return do_execve_common(filename, argv, envp, regs, false);
+}
+
void set_binfmt(struct linux_binfmt *new)
{
struct mm_struct *mm = current->mm;


\
 
 \ /
  Last update: 2011-02-25 19:05    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site