[PATCH 2/2] x86: Useless inode var and Coding style fixes

Geyslan G. Bem
2013-09-18T02:56:10Z

file size read only one time: useless prior value allocation.
It's not necessary to verify f_op in the load_aout_library, since the
prior kernel_read/vfs_read function already does.
Coding style and printk strings fixes.

Tested using qemu, a handcrafted a.out binary and a a.out linked with a
cross-compiled ld.

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
---
fs/binfmt_aout.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 89dec7f..a4af504 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -142,7 +142,8 @@ static int set_brk(unsigned long start, unsigned long end)
* memory and creates the pointer tables from them, and puts their
* addresses on the "stack", returning the new stack pointer value.
*/
-static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
+static unsigned long __user *create_aout_tables(char __user *p,
+ struct linux_binprm *bprm)
{
char __user * __user *argv;
char __user * __user *envp;
@@ -213,7 +214,8 @@ static int load_aout_binary(struct linux_binprm * bprm)
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
N_TRSIZE(ex) || N_DRSIZE(ex) ||
- i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
+ i_size_read(file_inode(bprm->file)) <
+ ex.a_text + ex.a_data + N_SYMSIZE(ex) + N_TXTOFF(ex)) {
return -ENOEXEC;
}

@@ -299,12 +301,12 @@ static int load_aout_binary(struct linux_binprm * bprm)

if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
{
- printk(KERN_WARNING
+ printk(KERN_WARNING
"fd_offset is not page aligned. Please convert program: %s\n",
bprm->file->f_path.dentry->d_name.name);
}

- if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
+ if ((fd_offset & ~PAGE_MASK) != 0) {
vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
read_code(bprm->file, N_TXTADDR(ex), fd_offset,
ex.a_text + ex.a_data);
@@ -350,14 +352,11 @@ beyond_if:

static int load_aout_library(struct file *file)
{
- struct inode * inode;
unsigned long bss, start_addr, len;
unsigned long error;
int retval;
struct exec ex;

- inode = file_inode(file);
-
retval = -ENOEXEC;
error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
if (error != sizeof(ex))
@@ -366,7 +365,8 @@ static int load_aout_library(struct file *file)
/* We come in here for the regular a.out style of shared libraries */
if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
- i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
+ i_size_read(file_inode(file)) <
+ ex.a_text + ex.a_data + N_SYMSIZE(ex) + N_TXTOFF(ex)) {
goto out;
}

@@ -374,7 +374,7 @@ static int load_aout_library(struct file *file)
* Requires a mmap handler. This prevents people from using a.out
* as part of an exploit attack against /proc-related vulnerabilities.
*/
- if (!file->f_op || !file->f_op->mmap)
+ if (!file->f_op->mmap)
goto out;

if (N_FLAGS(ex))
@@ -388,12 +388,12 @@ static int load_aout_library(struct file *file)
if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
if (printk_ratelimit())
{
- printk(KERN_WARNING
+ printk(KERN_WARNING
"N_TXTOFF is not page aligned. Please convert library: %s\n",
file->f_path.dentry->d_name.name);
}
vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
-
+
read_code(file, start_addr, N_TXTOFF(ex),
ex.a_text + ex.a_data);
retval = 0;
--
1.8.4