Merge branch 'exec_rm_compat' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg...

[pandora-kernel.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index 8328beb..c016896 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -55,6 +55,7 @@
 #include <linux/fs_struct.h>
 #include <linux/pipe_fs_i.h>
 #include <linux/oom.h>
+#include <linux/compat.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
@@ -166,8 +167,13 @@ out:
 }
 
 #ifdef CONFIG_MMU
-
-void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
+/*
+ * The nascent bprm->mm is not visible until exec_mmap() but it can
+ * use a lot of memory, account these pages in current->mm temporary
+ * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
+ * change the counter back via acct_arg_size(0).
+ */
+static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
 {
        struct mm_struct *mm = current->mm;
        long diff = (long)(pages - bprm->vma_pages);
@@ -186,7 +192,7 @@ void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
 #endif
 }
 
-struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
+static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
                int write)
 {
        struct page *page;
@@ -305,11 +311,11 @@ static bool valid_arg_len(struct linux_binprm *bprm, long len)
 
 #else
 
-void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
+static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
 {
 }
 
-struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
+static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
                int write)
 {
        struct page *page;
@@ -398,22 +404,56 @@ err:
        return err;
 }
 
+struct user_arg_ptr {
+#ifdef CONFIG_COMPAT
+       bool is_compat;
+#endif
+       union {
+               const char __user *const __user *native;
+#ifdef CONFIG_COMPAT
+               compat_uptr_t __user *compat;
+#endif
+       } ptr;
+};
+
+static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
+{
+       const char __user *native;
+
+#ifdef CONFIG_COMPAT
+       if (unlikely(argv.is_compat)) {
+               compat_uptr_t compat;
+
+               if (get_user(compat, argv.ptr.compat + nr))
+                       return ERR_PTR(-EFAULT);
+
+               return compat_ptr(compat);
+       }
+#endif
+
+       if (get_user(native, argv.ptr.native + nr))
+               return ERR_PTR(-EFAULT);
+
+       return native;
+}
+
 /*
  * count() counts the number of strings in array ARGV.
  */
-static int count(const char __user * const __user * argv, int max)
+static int count(struct user_arg_ptr argv, int max)
 {
        int i = 0;
 
-       if (argv != NULL) {
+       if (argv.ptr.native != NULL) {
                for (;;) {
-                       const char __user * p;
+                       const char __user *p = get_user_arg_ptr(argv, i);
 
-                       if (get_user(p, argv))
-                               return -EFAULT;
                        if (!p)
                                break;
-                       argv++;
+
+                       if (IS_ERR(p))
+                               return -EFAULT;
+
                        if (i++ >= max)
                                return -E2BIG;
 
@@ -430,7 +470,7 @@ static int count(const char __user * const __user * argv, int max)
  * processes's memory to the new process's stack.  The call to get_user_pages()
  * ensures the destination page is created and not swapped out.
  */
-static int copy_strings(int argc, const char __user *const __user *argv,
+static int copy_strings(int argc, struct user_arg_ptr argv,
                        struct linux_binprm *bprm)
 {
        struct page *kmapped_page = NULL;
@@ -443,16 +483,18 @@ static int copy_strings(int argc, const char __user *const __user *argv,
                int len;
                unsigned long pos;
 
-               if (get_user(str, argv+argc) ||
-                               !(len = strnlen_user(str, MAX_ARG_STRLEN))) {
-                       ret = -EFAULT;
+               ret = -EFAULT;
+               str = get_user_arg_ptr(argv, argc);
+               if (IS_ERR(str))
                        goto out;
-               }
 
-               if (!valid_arg_len(bprm, len)) {
-                       ret = -E2BIG;
+               len = strnlen_user(str, MAX_ARG_STRLEN);
+               if (!len)
+                       goto out;
+
+               ret = -E2BIG;
+               if (!valid_arg_len(bprm, len))
                        goto out;
-               }
 
                /* We're going to work our way backwords. */
                pos = bprm->p;
@@ -519,14 +561,19 @@ out:
 /*
  * Like copy_strings, but get argv and its values from kernel memory.
  */
-int copy_strings_kernel(int argc, const char *const *argv,
+int copy_strings_kernel(int argc, const char *const *__argv,
                        struct linux_binprm *bprm)
 {
        int r;
        mm_segment_t oldfs = get_fs();
+       struct user_arg_ptr argv = {
+               .ptr.native = (const char __user *const  __user *)__argv,
+       };
+
        set_fs(KERNEL_DS);
-       r = copy_strings(argc, (const char __user *const  __user *)argv, bprm);
+       r = copy_strings(argc, argv, bprm);
        set_fs(oldfs);
+
        return r;
 }
 EXPORT_SYMBOL(copy_strings_kernel);
@@ -1379,10 +1426,10 @@ EXPORT_SYMBOL(search_binary_handler);
 /*
  * sys_execve() executes a new program.
  */
-int do_execve(const char * filename,
-       const char __user *const __user *argv,
-       const char __user *const __user *envp,
-       struct pt_regs * regs)
+static int do_execve_common(const char *filename,
+                               struct user_arg_ptr argv,
+                               struct user_arg_ptr envp,
+                               struct pt_regs *regs)
 {
        struct linux_binprm *bprm;
        struct file *file;
@@ -1489,6 +1536,34 @@ 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)
+{
+       struct user_arg_ptr argv = { .ptr.native = __argv };
+       struct user_arg_ptr envp = { .ptr.native = __envp };
+       return do_execve_common(filename, argv, envp, regs);
+}
+
+#ifdef CONFIG_COMPAT
+int compat_do_execve(char *filename,
+       compat_uptr_t __user *__argv,
+       compat_uptr_t __user *__envp,
+       struct pt_regs *regs)
+{
+       struct user_arg_ptr argv = {
+               .is_compat = true,
+               .ptr.compat = __argv,
+       };
+       struct user_arg_ptr envp = {
+               .is_compat = true,
+               .ptr.compat = __envp,
+       };
+       return do_execve_common(filename, argv, envp, regs);
+}
+#endif
+
 void set_binfmt(struct linux_binfmt *new)
 {
        struct mm_struct *mm = current->mm;