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Message-Id: <1379646913-12445-1-git-send-email-geyslan@gmail.com>
Date: Fri, 20 Sep 2013 00:15:12 -0300
From: "Geyslan G. Bem" <geyslan@...il.com>
To: viro@...iv.linux.org.uk, linux-fsdevel@...r.kernel.org,
joe@...ches.com
Cc: linux-kernel@...r.kernel.org, "Geyslan G. Bem" <geyslan@...il.com>
Subject: [PATCH v3 1/2] binfmt_aout: x86: Useless inode var, printks coding style fixes
file size used only once, so removed due its useless prior allocation.
It's not necessary to verify f_op in the load_aout_library, since the
prior kernel_read/vfs_read function already does.
Made coding style fixes and printk replacements.
Tested using qemu, a handcrafted a.out binary and an a.out linked with a
cross-compiled ld.
Signed-off-by: Geyslan G. Bem <geyslan@...il.com>
---
fs/binfmt_aout.c | 98 +++++++++++++++++++++++++++-----------------------------
1 file changed, 48 insertions(+), 50 deletions(-)
diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c
index 89dec7f..c732b8e 100644
--- a/fs/binfmt_aout.c
+++ b/fs/binfmt_aout.c
@@ -25,13 +25,14 @@
#include <linux/init.h>
#include <linux/coredump.h>
#include <linux/slab.h>
+#include <linux/ratelimit.h>
+#include <linux/uaccess.h>
-#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/a.out-core.h>
static int load_aout_binary(struct linux_binprm *);
-static int load_aout_library(struct file*);
+static int load_aout_library(struct file *);
#ifdef CONFIG_COREDUMP
/*
@@ -62,7 +63,7 @@ static int aout_core_dump(struct coredump_params *cprm)
fs = get_fs();
set_fs(KERNEL_DS);
has_dumped = 1;
- strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
+ strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
dump.u_ar0 = offsetof(struct user, regs);
dump.signal = cprm->siginfo->si_signo;
aout_dump_thread(cprm->regs, &dump);
@@ -78,9 +79,11 @@ static int aout_core_dump(struct coredump_params *cprm)
/* make sure we actually have a data and stack area to dump */
set_fs(USER_DS);
- if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
+ if (!access_ok(VERIFY_READ, START_DATA(dump),
+ dump.u_dsize << PAGE_SHIFT))
dump.u_dsize = 0;
- if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
+ if (!access_ok(VERIFY_READ, START_STACK(dump),
+ dump.u_ssize << PAGE_SHIFT))
dump.u_ssize = 0;
set_fs(KERNEL_DS);
@@ -142,7 +145,8 @@ 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;
@@ -150,7 +154,8 @@ static unsigned long __user *create_aout_tables(char __user *p, struct linux_bin
int argc = bprm->argc;
int envc = bprm->envc;
- sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
+ sp = (void __user *) ((-(unsigned long) sizeof(char *))
+ & (unsigned long) p);
#ifdef __alpha__
/* whee.. test-programs are so much fun. */
put_user(0, --sp);
@@ -169,28 +174,28 @@ static unsigned long __user *create_aout_tables(char __user *p, struct linux_bin
sp -= argc+1;
argv = (char __user * __user *) sp;
#ifndef __alpha__
- put_user((unsigned long) envp,--sp);
- put_user((unsigned long) argv,--sp);
+ put_user((unsigned long) envp, --sp);
+ put_user((unsigned long) argv, --sp);
#endif
- put_user(argc,--sp);
+ put_user(argc, --sp);
current->mm->arg_start = (unsigned long) p;
- while (argc-->0) {
+ while (argc-- > 0) {
char c;
- put_user(p,argv++);
+ put_user(p, argv++);
do {
- get_user(c,p++);
+ get_user(c, p++);
} while (c);
}
- put_user(NULL,argv);
+ put_user(NULL, argv);
current->mm->arg_end = current->mm->env_start = (unsigned long) p;
- while (envc-->0) {
+ while (envc-- > 0) {
char c;
- put_user(p,envp++);
+ put_user(p, envp++);
do {
- get_user(c,p++);
+ get_user(c, p++);
} while (c);
}
- put_user(NULL,envp);
+ put_user(NULL, envp);
current->mm->env_end = (unsigned long) p;
return sp;
}
@@ -200,7 +205,7 @@ static unsigned long __user *create_aout_tables(char __user *p, struct linux_bin
* libraries. There is no binary dependent code anywhere else.
*/
-static int load_aout_binary(struct linux_binprm * bprm)
+static int load_aout_binary(struct linux_binprm *bprm)
{
struct pt_regs *regs = current_pt_regs();
struct exec ex;
@@ -213,7 +218,8 @@ 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;
}
@@ -292,19 +298,12 @@ static int load_aout_binary(struct linux_binprm * bprm)
}
} else {
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
- (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
- {
- printk(KERN_NOTICE "executable not page aligned\n");
- }
-
- if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
- {
- printk(KERN_WARNING
- "fd_offset is not page aligned. Please convert program: %s\n",
- bprm->file->f_path.dentry->d_name.name);
- }
+ (N_MAGIC(ex) != NMAGIC))
+ pr_notice_ratelimited("executable not page aligned\n");
- if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
+ if ((fd_offset & ~PAGE_MASK) != 0) {
+ pr_warn_ratelimited("fd_offset is not page aligned. Please convert program: %s\n",
+ bprm->file->f_path.dentry->d_name.name);
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);
@@ -312,9 +311,10 @@ static int load_aout_binary(struct linux_binprm * bprm)
}
error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
- PROT_READ | PROT_EXEC,
- MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
- fd_offset);
+ PROT_READ | PROT_EXEC,
+ (MAP_FIXED | MAP_PRIVATE
+ | MAP_DENYWRITE | MAP_EXECUTABLE),
+ fd_offset);
if (error != N_TXTADDR(ex)) {
send_sig(SIGKILL, current, 0);
@@ -323,8 +323,10 @@ static int load_aout_binary(struct linux_binprm * bprm)
error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
PROT_READ | PROT_WRITE | PROT_EXEC,
- MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
+ (MAP_FIXED | MAP_PRIVATE
+ | MAP_DENYWRITE | MAP_EXECUTABLE),
fd_offset + ex.a_text);
+
if (error != N_DATADDR(ex)) {
send_sig(SIGKILL, current, 0);
return error;
@@ -340,7 +342,8 @@ beyond_if:
}
current->mm->start_stack =
- (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
+ (unsigned long) create_aout_tables((char __user *) bprm->p,
+ bprm);
#ifdef __alpha__
regs->gp = ex.a_gpvalue;
#endif
@@ -350,14 +353,11 @@ 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 +366,8 @@ 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 +375,7 @@ 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))
@@ -383,17 +384,14 @@ static int load_aout_library(struct file *file)
/* For QMAGIC, the starting address is 0x20 into the page. We mask
this off to get the starting address for the page */
- start_addr = ex.a_entry & 0xfffff000;
+ start_addr = ex.a_entry & 0xfffff000;
if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
- if (printk_ratelimit())
- {
- printk(KERN_WARNING
- "N_TXTOFF is not page aligned. Please convert library: %s\n",
- file->f_path.dentry->d_name.name);
- }
+ pr_warn_ratelimited("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
--
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