Use the variable NAME instead of "\000" directly in kmod_test_0001().
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn --- tools/testing/selftests/kmod/kmod.sh | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kmod/kmod.sh b/tools/testing/selftests/kmod/kmod.sh index 3702dbc..da60c3b 100755 --- a/tools/testing/selftests/kmod/kmod.sh +++ b/tools/testing/selftests/kmod/kmod.sh @@ -341,7 +341,7 @@ kmod_test_0001_driver()
kmod_defaults_driver config_num_threads 1 - printf '\000' >"$DIR"/config_test_driver + printf $NAME >"$DIR"/config_test_driver config_trigger ${FUNCNAME[0]} config_expect_result ${FUNCNAME[0]} MODULE_NOT_FOUND } @@ -352,7 +352,7 @@ kmod_test_0001_fs()
kmod_defaults_fs config_num_threads 1 - printf '\000' >"$DIR"/config_test_fs + printf $NAME >"$DIR"/config_test_fs config_trigger ${FUNCNAME[0]} config_expect_result ${FUNCNAME[0]} -EINVAL }
There exists redundant "be an" in the comment, remove it.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn --- kernel/kmod.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 37c3c4b..3cd075c 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -36,9 +36,8 @@ * * If you need less than 50 threads would mean we're dealing with systems * smaller than 3200 pages. This assumes you are capable of having ~13M memory, - * and this would only be an be an upper limit, after which the OOM killer - * would take effect. Systems like these are very unlikely if modules are - * enabled. + * and this would only be an upper limit, after which the OOM killer would take + * effect. Systems like these are very unlikely if modules are enabled. */ #define MAX_KMOD_CONCURRENT 50 static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
On Sat, Apr 18, 2020 at 01:19:58PM +0800, Tiezhu Yang wrote:
There exists redundant "be an" in the comment, remove it.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
Acked-by: Luis Chamberlain mcgrof@kernel.org
Luis
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn --- kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256 + /* * Assuming: * @@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
+ if (strlen(module_name) == 0) + return MODULE_NOT_FOUND; + ret = security_kernel_module_request(module_name); if (ret) return ret;
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@ #include <trace/events/module.h> +#define MODULE_NOT_FOUND 256
/*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
- if (strlen(module_name) == 0)
return MODULE_NOT_FOUND;
I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
- ret = security_kernel_module_request(module_name); if (ret) return ret;
-- 2.1.0
On Fri, Apr 17, 2020 at 11:45 PM Luis Chamberlain mcgrof@kernel.org wrote:
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256
/*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
if (strlen(module_name) == 0)return MODULE_NOT_FOUND;I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
Also, are we testing for this condition yet? If not can we add one?
On 04/18/2020 01:48 PM, Luis Chamberlain wrote:
On Fri, Apr 17, 2020 at 11:45 PM Luis Chamberlain mcgrof@kernel.org wrote:
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256
- /*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
if (strlen(module_name) == 0)return MODULE_NOT_FOUND;I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
Also, are we testing for this condition yet? If not can we add one?
Yes, kmod_test_0001_driver() in tools/testing/selftests/kmod/kmod.sh tests this case and expects result MODULE_NOT_FOUND which is 256.
On Sat, Apr 18, 2020 at 01:58:45PM +0800, Tiezhu Yang wrote:
On 04/18/2020 01:48 PM, Luis Chamberlain wrote:
On Fri, Apr 17, 2020 at 11:45 PM Luis Chamberlain mcgrof@kernel.org wrote:
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256
- /*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
if (strlen(module_name) == 0)return MODULE_NOT_FOUND;I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
Also, are we testing for this condition yet? If not can we add one?
Yes, kmod_test_0001_driver() in tools/testing/selftests/kmod/kmod.sh tests this case and expects result MODULE_NOT_FOUND which is 256.
OK I see now I had put:
errno_name_to_val() { case "$1" in # kmod calls modprobe and upon of a module not found # modprobe returns just 1... However in the # kernel we *sometimes* see 256... MODULE_NOT_FOUND) echo 256;;
I found that through testing, however there was nothing set in stone, nothing documented. While you are at it, can you find the places where this is returned in the kernel code? We should clear this up and se things straight. We cannot change what we gave userspace already though.
Luis
On 04/18/2020 03:19 PM, Luis Chamberlain wrote:
On Sat, Apr 18, 2020 at 01:58:45PM +0800, Tiezhu Yang wrote:
On 04/18/2020 01:48 PM, Luis Chamberlain wrote:
On Fri, Apr 17, 2020 at 11:45 PM Luis Chamberlain mcgrof@kernel.org wrote:
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256
- /*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
if (strlen(module_name) == 0)return MODULE_NOT_FOUND;I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
Also, are we testing for this condition yet? If not can we add one?
Yes, kmod_test_0001_driver() in tools/testing/selftests/kmod/kmod.sh tests this case and expects result MODULE_NOT_FOUND which is 256.
OK I see now I had put:
errno_name_to_val() { case "$1" in # kmod calls modprobe and upon of a module not found # modprobe returns just 1... However in the # kernel we *sometimes* see 256... MODULE_NOT_FOUND) echo 256;;
I found that through testing, however there was nothing set in stone, nothing documented. While you are at it, can you find the places where this is returned in the kernel code? We should clear this up and se things straight. We cannot change what we gave userspace already though.
Call Trace:
__request_module() | | call_modprobe() | | call_usermodehelper_exec() -- retval = sub_info->retval; | | call_usermodehelper_exec_work() | | call_usermodehelper_exec_sync() -- sub_info->retval = ret; | | --> call_usermodehelper_exec_async() --> do_execve() | kernel_wait4(pid, (int __user *)&ret, 0, NULL);
__request_module() returns the exist status of child process, if module name is empty or non-exist, sub_info->retval is 256 after call kernel_wait4().
Should I add this analysis to the commit message?
Thanks, Tiezhu Yang
Luis
On 04/20/2020 12:08 PM, Tiezhu Yang wrote:
On 04/18/2020 03:19 PM, Luis Chamberlain wrote:
On Sat, Apr 18, 2020 at 01:58:45PM +0800, Tiezhu Yang wrote:
On 04/18/2020 01:48 PM, Luis Chamberlain wrote:
On Fri, Apr 17, 2020 at 11:45 PM Luis Chamberlain mcgrof@kernel.org wrote:
On Sat, Apr 18, 2020 at 01:19:59PM +0800, Tiezhu Yang wrote:
If module name is empty, it is better to return directly at the beginning of request_module() without doing the needless call_modprobe() operation.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/kmod.c b/kernel/kmod.c index 3cd075c..5851444 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -28,6 +28,8 @@
#include <trace/events/module.h>
+#define MODULE_NOT_FOUND 256
- /*
- Assuming:
@@ -144,6 +146,9 @@ int __request_module(bool wait, const char *fmt, ...) if (ret >= MODULE_NAME_LEN) return -ENAMETOOLONG;
if (strlen(module_name) == 0)return MODULE_NOT_FOUND;I'd rather we just use something standard like -EINVAL. What do we return if its not found? Then use that value.
Also, are we testing for this condition yet? If not can we add one?
Yes, kmod_test_0001_driver() in tools/testing/selftests/kmod/kmod.sh tests this case and expects result MODULE_NOT_FOUND which is 256.
OK I see now I had put:
errno_name_to_val() { case "$1" in # kmod calls modprobe and upon of a module not found # modprobe returns just 1... However in the # kernel we *sometimes* see 256... MODULE_NOT_FOUND) echo 256;;
I found that through testing, however there was nothing set in stone, nothing documented. While you are at it, can you find the places where this is returned in the kernel code? We should clear this up and se things straight. We cannot change what we gave userspace already though.
Call Trace:
__request_module() | | call_modprobe() | | call_usermodehelper_exec() -- retval = sub_info->retval; | | call_usermodehelper_exec_work() | | call_usermodehelper_exec_sync() -- sub_info->retval = ret; | | --> call_usermodehelper_exec_async() --> do_execve() | kernel_wait4(pid, (int __user *)&ret, 0, NULL);
__request_module() returns the exist status of child process, if module name
Sorry for the typo: exist status --> exit status
is empty or non-exist, sub_info->retval is 256 after call kernel_wait4().
Should I add this analysis to the commit message?
Thanks, Tiezhu Yang
Luis
It should set config->test_fs instead of config->test_driver as NULL after kfree_const(config->test_fs) to avoid potential double free.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn --- lib/test_kmod.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/test_kmod.c b/lib/test_kmod.c index e651c37..eab5277 100644 --- a/lib/test_kmod.c +++ b/lib/test_kmod.c @@ -745,7 +745,7 @@ static int trigger_config_run_type(struct kmod_test_device *test_dev, break; case TEST_KMOD_FS_TYPE: kfree_const(config->test_fs); - config->test_driver = NULL; + config->test_fs = NULL; copied = config_copy_test_fs(config, test_str, strlen(test_str)); break;
On Sat, Apr 18, 2020 at 01:20:00PM +0800, Tiezhu Yang wrote:
It should set config->test_fs instead of config->test_driver as NULL after kfree_const(config->test_fs) to avoid potential double free.
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
Acked-by: Luis Chamberlain mcgrof@kernel.org
Luis
On Sat, Apr 18, 2020 at 01:19:57PM +0800, Tiezhu Yang wrote:
Use the variable NAME instead of "\000" directly in kmod_test_0001().
Signed-off-by: Tiezhu Yang yangtiezhu@loongson.cn
Acked-by: Luis Chamberlain mcgrof@kernel.org
Luis
linux-kselftest-mirror@lists.linaro.org
-
Luis Chamberlain -
Tiezhu Yang