uml: simplify helper stack handling
run_helper and run_helper_thread had arguments which were the same in all
callers. run_helper's stack_out was always NULL and run_helper_thread's
stack_order was always 0. These are now gone, and the constants folded
into the code.
Also fixed leaks of the helper stack in the AIO and SIGIO code.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/um/os-Linux/aio.c b/arch/um/os-Linux/aio.c
index 9bf944f..b126df4 100644
--- a/arch/um/os-Linux/aio.c
+++ b/arch/um/os-Linux/aio.c
@@ -177,6 +177,7 @@
static int aio_req_fd_r = -1;
static int aio_req_fd_w = -1;
static int aio_pid = -1;
+static unsigned long aio_stack;
static int not_aio_thread(void *arg)
{
@@ -212,7 +213,6 @@
static int init_aio_24(void)
{
- unsigned long stack;
int fds[2], err;
err = os_pipe(fds, 1, 1);
@@ -227,7 +227,7 @@
goto out_close_pipe;
err = run_helper_thread(not_aio_thread, NULL,
- CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+ CLONE_FILES | CLONE_VM | SIGCHLD, &aio_stack);
if(err < 0)
goto out_close_pipe;
@@ -252,7 +252,6 @@
#define DEFAULT_24_AIO 0
static int init_aio_26(void)
{
- unsigned long stack;
int err;
if(io_setup(256, &ctx)){
@@ -263,7 +262,7 @@
}
err = run_helper_thread(aio_thread, NULL,
- CLONE_FILES | CLONE_VM | SIGCHLD, &stack, 0);
+ CLONE_FILES | CLONE_VM | SIGCHLD, &aio_stack);
if(err < 0)
return err;
@@ -365,8 +364,10 @@
static void exit_aio(void)
{
- if(aio_pid != -1)
+ if (aio_pid != -1) {
os_kill_process(aio_pid, 1);
+ free_stack(aio_stack, 0);
+ }
}
__uml_exitcall(exit_aio);
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index acba301..cac01b3 100644
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -117,7 +117,7 @@
pe_data.control_remote = control_remote;
pe_data.control_me = control_me;
pe_data.data_me = data_me;
- pid = run_helper(etap_pre_exec, &pe_data, args, NULL);
+ pid = run_helper(etap_pre_exec, &pe_data, args);
if(pid < 0)
err = pid;
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 11a9779..f848b4e 100644
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -83,7 +83,7 @@
data.stdout = remote;
data.close_me = me;
- pid = run_helper(tuntap_pre_exec, &data, argv, NULL);
+ pid = run_helper(tuntap_pre_exec, &data, argv);
if(pid < 0)
return -pid;
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 97bed16..9cf48d0 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -44,17 +44,13 @@
/* Returns either the pid of the child process we run or -E* on failure.
* XXX The alloc_stack here breaks if this is called in the tracing thread, so
* we need to receive a preallocated stack (a local buffer is ok). */
-int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv,
- unsigned long *stack_out)
+int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
{
struct helper_data data;
unsigned long stack, sp;
int pid, fds[2], ret, n;
- if ((stack_out != NULL) && (*stack_out != 0))
- stack = *stack_out;
- else
- stack = alloc_stack(0, __cant_sleep());
+ stack = alloc_stack(0, __cant_sleep());
if (stack == 0)
return -ENOMEM;
@@ -113,22 +109,21 @@
close(fds[1]);
close(fds[0]);
out_free:
- if ((stack_out == NULL) || (*stack_out == 0))
- free_stack(stack, 0);
+ free_stack(stack, 0);
return ret;
}
int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
- unsigned long *stack_out, int stack_order)
+ unsigned long *stack_out)
{
unsigned long stack, sp;
int pid, status, err;
- stack = alloc_stack(stack_order, __cant_sleep());
+ stack = alloc_stack(0, __cant_sleep());
if (stack == 0)
return -ENOMEM;
- sp = stack + (UM_KERN_PAGE_SIZE << stack_order) - sizeof(void *);
+ sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *);
pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
if (pid < 0) {
err = -errno;
@@ -147,7 +142,7 @@
if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
printk("run_helper_thread - thread returned status "
"0x%x\n", status);
- free_stack(stack, stack_order);
+ free_stack(stack, 0);
} else
*stack_out = stack;
return pid;
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c
index 8d4e0c6..2c23cb2 100644
--- a/arch/um/os-Linux/sigio.c
+++ b/arch/um/os-Linux/sigio.c
@@ -26,6 +26,7 @@
* exitcall.
*/
static int write_sigio_pid = -1;
+static unsigned long write_sigio_stack;
/* These arrays are initialized before the sigio thread is started, and
* the descriptors closed after it is killed. So, it can't see them change.
@@ -144,8 +145,10 @@
return;
fail:
/* Critical section start */
- if(write_sigio_pid != -1)
+ if (write_sigio_pid != -1) {
os_kill_process(write_sigio_pid, 1);
+ free_stack(write_sigio_stack, 0);
+ }
write_sigio_pid = -1;
close(sigio_private[0]);
close(sigio_private[1]);
@@ -243,7 +246,6 @@
static void write_sigio_workaround(void)
{
- unsigned long stack;
struct pollfd *p;
int err;
int l_write_sigio_fds[2];
@@ -293,7 +295,8 @@
memcpy(sigio_private, l_sigio_private, sizeof(l_sigio_private));
write_sigio_pid = run_helper_thread(write_sigio_thread, NULL,
- CLONE_FILES | CLONE_VM, &stack, 0);
+ CLONE_FILES | CLONE_VM,
+ &write_sigio_stack);
if (write_sigio_pid < 0)
goto out_clear;
@@ -356,10 +359,12 @@
static void sigio_cleanup(void)
{
- if(write_sigio_pid != -1){
- os_kill_process(write_sigio_pid, 1);
- write_sigio_pid = -1;
- }
+ if (write_sigio_pid == -1)
+ return;
+
+ os_kill_process(write_sigio_pid, 1);
+ free_stack(write_sigio_stack, 0);
+ write_sigio_pid = -1;
}
__uml_exitcall(sigio_cleanup);