* [RESEND v2 0/4] Fix some issues about kmod
@ 2020-04-20 11:58 Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 1/4] selftests: kmod: Use variable NAME in kmod_test_0001() Tiezhu Yang
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Tiezhu Yang @ 2020-04-20 11:58 UTC (permalink / raw)
To: Luis Chamberlain, Shuah Khan, Andrew Morton, Jessica Yu
Cc: linux-kselftest, linux-kernel, Markus Elfring, Xuefeng Li
Tiezhu Yang (4):
selftests: kmod: Use variable NAME in kmod_test_0001()
kmod: Remove redundant "be an" in the comment
kmod: Return directly if module name is empty in request_module()
test_kmod: Avoid potential double free in trigger_config_run_type()
kernel/kmod.c | 10 +++++++---
lib/test_kmod.c | 2 +-
tools/testing/selftests/kmod/kmod.sh | 4 ++--
3 files changed, 10 insertions(+), 6 deletions(-)
--
2.1.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [RESEND v2 1/4] selftests: kmod: Use variable NAME in kmod_test_0001()
2020-04-20 11:58 [RESEND v2 0/4] Fix some issues about kmod Tiezhu Yang
@ 2020-04-20 11:58 ` Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 2/4] kmod: Remove redundant "be an" in the comment Tiezhu Yang
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Tiezhu Yang @ 2020-04-20 11:58 UTC (permalink / raw)
To: Luis Chamberlain, Shuah Khan, Andrew Morton, Jessica Yu
Cc: linux-kselftest, linux-kernel, Markus Elfring, Xuefeng Li
Use the variable NAME instead of "\000" directly in kmod_test_0001().
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
v2:
- just add the Acked-by tag
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
}
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [RESEND v2 2/4] kmod: Remove redundant "be an" in the comment
2020-04-20 11:58 [RESEND v2 0/4] Fix some issues about kmod Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 1/4] selftests: kmod: Use variable NAME in kmod_test_0001() Tiezhu Yang
@ 2020-04-20 11:58 ` Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 3/4] kmod: Return directly if module name is empty in request_module() Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 4/4] test_kmod: Avoid potential double free in trigger_config_run_type() Tiezhu Yang
3 siblings, 0 replies; 5+ messages in thread
From: Tiezhu Yang @ 2020-04-20 11:58 UTC (permalink / raw)
To: Luis Chamberlain, Shuah Khan, Andrew Morton, Jessica Yu
Cc: linux-kselftest, linux-kernel, Markus Elfring, Xuefeng Li
There exists redundant "be an" in the comment, remove it.
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
v2:
- just add the Acked-by tag
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);
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [RESEND v2 3/4] kmod: Return directly if module name is empty in request_module()
2020-04-20 11:58 [RESEND v2 0/4] Fix some issues about kmod Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 1/4] selftests: kmod: Use variable NAME in kmod_test_0001() Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 2/4] kmod: Remove redundant "be an" in the comment Tiezhu Yang
@ 2020-04-20 11:58 ` Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 4/4] test_kmod: Avoid potential double free in trigger_config_run_type() Tiezhu Yang
3 siblings, 0 replies; 5+ messages in thread
From: Tiezhu Yang @ 2020-04-20 11:58 UTC (permalink / raw)
To: Luis Chamberlain, Shuah Khan, Andrew Morton, Jessica Yu
Cc: linux-kselftest, linux-kernel, Markus Elfring, Xuefeng Li
If module name is empty, it is better to return directly at the beginning
of request_module() without doing the needless call_modprobe() operation.
Call trace:
request_module()
|
|
__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);
sub_info->retval is 256 after call kernel_wait4(), the function
call_usermodehelper_exec() returns sub_info->retval which is 256,
then call_modprobe() and __request_module() returns 256.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
v2:
- update the commit message to explain the detailed reason
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;
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [RESEND v2 4/4] test_kmod: Avoid potential double free in trigger_config_run_type()
2020-04-20 11:58 [RESEND v2 0/4] Fix some issues about kmod Tiezhu Yang
` (2 preceding siblings ...)
2020-04-20 11:58 ` [RESEND v2 3/4] kmod: Return directly if module name is empty in request_module() Tiezhu Yang
@ 2020-04-20 11:58 ` Tiezhu Yang
3 siblings, 0 replies; 5+ messages in thread
From: Tiezhu Yang @ 2020-04-20 11:58 UTC (permalink / raw)
To: Luis Chamberlain, Shuah Khan, Andrew Morton, Jessica Yu
Cc: linux-kselftest, linux-kernel, Markus Elfring, Xuefeng Li
Reset the member “test_fs” of the test configuration after a call
of the function “kfree_const” to a null pointer so that a double
memory release will not be performed.
Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader")
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
v2:
- update the commit message suggested by Markus Elfring
- add the Fixes tag
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;
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-04-20 11:59 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-04-20 11:58 [RESEND v2 0/4] Fix some issues about kmod Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 1/4] selftests: kmod: Use variable NAME in kmod_test_0001() Tiezhu Yang
2020-04-20 11:58 ` [RESEND v2 2/4] kmod: Remove redundant "be an" in the comment Tiezhu Yang
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