[LTP] [PATCH v2] ht_affinity.c: fix ht_affinity test failure

[Haifeng Xu]

Running ht_affinity test fails:

	smt_smp_affinity    0  TINFO  :  Set affinity through system call
	smt_smp_affinity    0  TINFO  :  Set test process affinity.
	mask: 1
	smt_smp_affinity    0  TINFO  :  ...Error

	...

	smt_smp_affinity    0  TINFO  :  Set test process affinity.
	mask: c0000000
	smt_smp_affinity    0  TINFO  :  ...Error
	smt_smp_affinity    3  TFAIL  :  ht_affinity.c:240: System call setaffinity() is error.

The type of cpumask pointer used in set_affinity() is unsigned long, but
ht_affinity used a unsigned int pointer. When kernel copy cpumask from
user-space pointer, the high 32bit of cpumask is a random value. So the
process can't be bind to the cpu specified by users.

After using sizeof on the mask instead of sizeof(unsigned long), ht_affinity
test succeeds:

	smt_smp_affinity    0  TINFO  :  Set affinity through system call
	smt_smp_affinity    0  TINFO  :  Set test process affinity.
	mask: 1
	smt_smp_affinity    0  TINFO  :  ...OK

	...

	smt_smp_affinity    0  TINFO  :  Set test process affinity.
	mask: c0000000
	smt_smp_affinity    0  TINFO  :  ...OK
	smt_smp_affinity    3  TPASS  :  System call setaffinity() is OK.

Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Suggested-by: Cyril Hrubis <chrubis@suse.cz>
---
Changes since v1:
- Don't change the type of the mask and use sizeof on it. 
---
 .../kernel/sched/hyperthreading/ht_affinity/ht_affinity.c     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/testcases/kernel/sched/hyperthreading/ht_affinity/ht_affinity.c b/testcases/kernel/sched/hyperthreading/ht_affinity/ht_affinity.c
index f6e9f2745..3c2fe1bf1 100644
--- a/testcases/kernel/sched/hyperthreading/ht_affinity/ht_affinity.c
+++ b/testcases/kernel/sched/hyperthreading/ht_affinity/ht_affinity.c
@@ -67,7 +67,7 @@ int HT_SetAffinity(void)
 		tst_resm(TINFO, "Set test process affinity.");
 		printf("mask: %x\n", mask);
 
-		sched_setaffinity(pid, sizeof(unsigned long), &mask);
+		sched_setaffinity(pid, sizeof(mask), &mask);
 
 		for (j = 0; j < 10; j++) {
 			for (k = 0; k < 10; k++) {
@@ -95,7 +95,7 @@ int HT_SetAffinity(void)
 		tst_resm(TINFO, "Set test process affinity.");
 		printf("mask: %x\n", mask);
 
-		sched_setaffinity(pid, sizeof(unsigned long), &mask);
+		sched_setaffinity(pid, sizeof(mask), &mask);
 
 		for (j = 0; j < 10; j++) {
 			for (k = 0; k < 10; k++) {
-- 
2.25.1