diff options
| -rw-r--r-- | fs/proc/base.c | 13 | ||||
| -rw-r--r-- | mm/util.c | 16 |
2 files changed, 22 insertions, 7 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index e665097c1da5..4f764c2ac1a5 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -953,6 +953,7 @@ static ssize_t environ_read(struct file *file, char __user *buf, unsigned long src = *ppos; int ret = 0; struct mm_struct *mm = file->private_data; + unsigned long env_start, env_end; if (!mm) return 0; @@ -964,19 +965,25 @@ static ssize_t environ_read(struct file *file, char __user *buf, ret = 0; if (!atomic_inc_not_zero(&mm->mm_users)) goto free; + + down_read(&mm->mmap_sem); + env_start = mm->env_start; + env_end = mm->env_end; + up_read(&mm->mmap_sem); + while (count > 0) { size_t this_len, max_len; int retval; - if (src >= (mm->env_end - mm->env_start)) + if (src >= (env_end - env_start)) break; - this_len = mm->env_end - (mm->env_start + src); + this_len = env_end - (env_start + src); max_len = min_t(size_t, PAGE_SIZE, count); this_len = min(max_len, this_len); - retval = access_remote_vm(mm, (mm->env_start + src), + retval = access_remote_vm(mm, (env_start + src), page, this_len, 0); if (retval <= 0) { diff --git a/mm/util.c b/mm/util.c index 6d1f9200f74e..c108a6542d05 100644 --- a/mm/util.c +++ b/mm/util.c @@ -476,17 +476,25 @@ int get_cmdline(struct task_struct *task, char *buffer, int buflen) int res = 0; unsigned int len; struct mm_struct *mm = get_task_mm(task); + unsigned long arg_start, arg_end, env_start, env_end; if (!mm) goto out; if (!mm->arg_end) goto out_mm; /* Shh! No looking before we're done */ - len = mm->arg_end - mm->arg_start; + down_read(&mm->mmap_sem); + arg_start = mm->arg_start; + arg_end = mm->arg_end; + env_start = mm->env_start; + env_end = mm->env_end; + up_read(&mm->mmap_sem); + + len = arg_end - arg_start; if (len > buflen) len = buflen; - res = access_process_vm(task, mm->arg_start, buffer, len, 0); + res = access_process_vm(task, arg_start, buffer, len, 0); /* * If the nul at the end of args has been overwritten, then @@ -497,10 +505,10 @@ int get_cmdline(struct task_struct *task, char *buffer, int buflen) if (len < res) { res = len; } else { - len = mm->env_end - mm->env_start; + len = env_end - env_start; if (len > buflen - res) len = buflen - res; - res += access_process_vm(task, mm->env_start, + res += access_process_vm(task, env_start, buffer+res, len, 0); res = strnlen(buffer, res); } |