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Diffstat (limited to 'fs/proc/base.c')
-rw-r--r--fs/proc/base.c134
1 files changed, 53 insertions, 81 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c
index af128b374143..44dec22e5e9e 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -213,10 +213,14 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
char *page;
unsigned long count = _count;
unsigned long arg_start, arg_end, env_start, env_end;
- unsigned long len1, len2, len;
- unsigned long p;
+ unsigned long len1, len2;
+ char __user *buf0 = buf;
+ struct {
+ unsigned long p;
+ unsigned long len;
+ } cmdline[2];
char c;
- ssize_t rv;
+ int rv;
BUG_ON(*pos < 0);
@@ -239,12 +243,12 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
goto out_mmput;
}
- down_read(&mm->mmap_sem);
+ spin_lock(&mm->arg_lock);
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);
+ spin_unlock(&mm->arg_lock);
BUG_ON(arg_start > arg_end);
BUG_ON(env_start > env_end);
@@ -253,61 +257,31 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
len2 = env_end - env_start;
/* Empty ARGV. */
- if (len1 == 0) {
- rv = 0;
- goto out_free_page;
- }
+ if (len1 == 0)
+ goto end;
+
/*
* Inherently racy -- command line shares address space
* with code and data.
*/
- rv = access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON);
- if (rv <= 0)
- goto out_free_page;
-
- rv = 0;
+ if (access_remote_vm(mm, arg_end - 1, &c, 1, FOLL_ANON) != 1)
+ goto end;
+ cmdline[0].p = arg_start;
+ cmdline[0].len = len1;
if (c == '\0') {
/* Command line (set of strings) occupies whole ARGV. */
- if (len1 <= *pos)
- goto out_free_page;
-
- p = arg_start + *pos;
- len = len1 - *pos;
- while (count > 0 && len > 0) {
- unsigned int _count;
- int nr_read;
-
- _count = min3(count, len, PAGE_SIZE);
- nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
- if (nr_read < 0)
- rv = nr_read;
- if (nr_read <= 0)
- goto out_free_page;
-
- if (copy_to_user(buf, page, nr_read)) {
- rv = -EFAULT;
- goto out_free_page;
- }
-
- p += nr_read;
- len -= nr_read;
- buf += nr_read;
- count -= nr_read;
- rv += nr_read;
- }
+ cmdline[1].len = 0;
} else {
/*
* Command line (1 string) occupies ARGV and
* extends into ENVP.
*/
- struct {
- unsigned long p;
- unsigned long len;
- } cmdline[2] = {
- { .p = arg_start, .len = len1 },
- { .p = env_start, .len = len2 },
- };
+ cmdline[1].p = env_start;
+ cmdline[1].len = len2;
+ }
+
+ {
loff_t pos1 = *pos;
unsigned int i;
@@ -317,44 +291,40 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
i++;
}
while (i < 2) {
+ unsigned long p;
+ unsigned long len;
+
p = cmdline[i].p + pos1;
len = cmdline[i].len - pos1;
while (count > 0 && len > 0) {
- unsigned int _count, l;
- int nr_read;
- bool final;
-
- _count = min3(count, len, PAGE_SIZE);
- nr_read = access_remote_vm(mm, p, page, _count, FOLL_ANON);
- if (nr_read < 0)
- rv = nr_read;
- if (nr_read <= 0)
- goto out_free_page;
+ unsigned int nr_read, nr_write;
+
+ nr_read = min3(count, len, PAGE_SIZE);
+ nr_read = access_remote_vm(mm, p, page, nr_read, FOLL_ANON);
+ if (nr_read == 0)
+ goto end;
/*
* Command line can be shorter than whole ARGV
* even if last "marker" byte says it is not.
*/
- final = false;
- l = strnlen(page, nr_read);
- if (l < nr_read) {
- nr_read = l;
- final = true;
- }
+ if (c == '\0')
+ nr_write = nr_read;
+ else
+ nr_write = strnlen(page, nr_read);
- if (copy_to_user(buf, page, nr_read)) {
+ if (copy_to_user(buf, page, nr_write)) {
rv = -EFAULT;
goto out_free_page;
}
- p += nr_read;
- len -= nr_read;
- buf += nr_read;
- count -= nr_read;
- rv += nr_read;
+ p += nr_write;
+ len -= nr_write;
+ buf += nr_write;
+ count -= nr_write;
- if (final)
- goto out_free_page;
+ if (nr_write < nr_read)
+ goto end;
}
/* Only first chunk can be read partially. */
@@ -363,12 +333,13 @@ static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
}
}
+end:
+ *pos += buf - buf0;
+ rv = buf - buf0;
out_free_page:
free_page((unsigned long)page);
out_mmput:
mmput(mm);
- if (rv > 0)
- *pos += rv;
return rv;
}
@@ -430,7 +401,6 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
struct stack_trace trace;
unsigned long *entries;
int err;
- int i;
entries = kmalloc(MAX_STACK_TRACE_DEPTH * sizeof(*entries), GFP_KERNEL);
if (!entries)
@@ -443,6 +413,8 @@ static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
err = lock_trace(task);
if (!err) {
+ unsigned int i;
+
save_stack_trace_tsk(task, &trace);
for (i = 0; i < trace.nr_entries; i++) {
@@ -927,10 +899,10 @@ static ssize_t environ_read(struct file *file, char __user *buf,
if (!mmget_not_zero(mm))
goto free;
- down_read(&mm->mmap_sem);
+ spin_lock(&mm->arg_lock);
env_start = mm->env_start;
env_end = mm->env_end;
- up_read(&mm->mmap_sem);
+ spin_unlock(&mm->arg_lock);
while (count > 0) {
size_t this_len, max_len;
@@ -1784,9 +1756,9 @@ int pid_getattr(const struct path *path, struct kstat *stat,
generic_fillattr(inode, stat);
- rcu_read_lock();
stat->uid = GLOBAL_ROOT_UID;
stat->gid = GLOBAL_ROOT_GID;
+ rcu_read_lock();
task = pid_task(proc_pid(inode), PIDTYPE_PID);
if (task) {
if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
@@ -1875,7 +1847,7 @@ const struct dentry_operations pid_dentry_operations =
* by stat.
*/
bool proc_fill_cache(struct file *file, struct dir_context *ctx,
- const char *name, int len,
+ const char *name, unsigned int len,
instantiate_t instantiate, struct task_struct *task, const void *ptr)
{
struct dentry *child, *dir = file->f_path.dentry;
@@ -3251,7 +3223,7 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx)
iter.task;
iter.tgid += 1, iter = next_tgid(ns, iter)) {
char name[10 + 1];
- int len;
+ unsigned int len;
cond_resched();
if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
@@ -3578,7 +3550,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx)
task;
task = next_tid(task), ctx->pos++) {
char name[10 + 1];
- int len;
+ unsigned int len;
tid = task_pid_nr_ns(task, ns);
len = snprintf(name, sizeof(name), "%u", tid);
if (!proc_fill_cache(file, ctx, name, len,
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-30 15:50:30 +0300