Reset nr_hugepages to zero before the start of the test.
If a non-zero number of hugepages is already set before the start of the
test, the following problems arise:
- The probability of the test getting OOM-killed increases.
Proof: The test wants to run on 80% of available memory to prevent
OOM-killing (see original code comments). Let the value of mem_free at the
start of the test, when nr_hugepages = 0, be x. In the other case, when
nr_hugepages > 0, let the memory consumed by hugepages be y. In the former
case, the test operates on 0.8 * x of memory. In the latter, the test
operates on 0.8 * (x - y) of memory, with y already filled, hence, memory
consumed is y + 0.8 * (x - y) = 0.8 * x + 0.2 * y > 0.8 * x. Q.E.D
- The probability of a bogus test success increases.
Proof: Let the memory consumed by hugepages be greater than 25% of x,
with x and y defined as above. The definition of compaction_index is
c_index = (x - y)/z where z is the memory consumed by hugepages after
trying to increase them again. In check_compaction(), we set the number
of hugepages to zero, and then increase them back; the probability that
they will be set back to consume at least y amount of memory again is
very high (since there is not much delay between the two attempts of
changing nr_hugepages). Hence, z >= y > (x/4) (by the 25% assumption).
Therefore,
c_index = (x - y)/z <= (x - y)/y = x/y - 1 < 4 - 1 = 3
hence, c_index can always be forced to be less than 3, thereby the test
succeeding always. Q.E.D
Changes in v2:
- Handle unsigned long number of hugepages
v1:
- https://lore.kernel.org/all/20240515093633.54814-3-dev.jain@arm.com/
NOTE: This patch depends on the previous one.
Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dev Jain <dev.jain(a)arm.com>
---
tools/testing/selftests/mm/compaction_test.c | 71 ++++++++++++++------
1 file changed, 49 insertions(+), 22 deletions(-)
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 5e9bd1da9370..e140558e6f53 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -82,13 +82,16 @@ int prereq(void)
return -1;
}
-int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
+int check_compaction(unsigned long mem_free, unsigned long hugepage_size,
+ unsigned long initial_nr_hugepages)
{
unsigned long nr_hugepages_ul;
int fd, ret = -1;
int compaction_index = 0;
- char initial_nr_hugepages[20] = {0};
char nr_hugepages[20] = {0};
+ char init_nr_hugepages[20] = {0};
+
+ sprintf(init_nr_hugepages, "%lu", initial_nr_hugepages);
/* We want to test with 80% of available memory. Else, OOM killer comes
in to play */
@@ -102,23 +105,6 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
goto out;
}
- if (read(fd, initial_nr_hugepages, sizeof(initial_nr_hugepages)) <= 0) {
- ksft_print_msg("Failed to read from /proc/sys/vm/nr_hugepages: %s\n",
- strerror(errno));
- goto close_fd;
- }
-
- lseek(fd, 0, SEEK_SET);
-
- /* Start with the initial condition of 0 huge pages*/
- if (write(fd, "0", sizeof(char)) != sizeof(char)) {
- ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n",
- strerror(errno));
- goto close_fd;
- }
-
- lseek(fd, 0, SEEK_SET);
-
/* Request a large number of huge pages. The Kernel will allocate
as much as it can */
if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
@@ -146,8 +132,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
lseek(fd, 0, SEEK_SET);
- if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages))
- != strlen(initial_nr_hugepages)) {
+ if (write(fd, init_nr_hugepages, strlen(init_nr_hugepages))
+ != strlen(init_nr_hugepages)) {
ksft_print_msg("Failed to write value to /proc/sys/vm/nr_hugepages: %s\n",
strerror(errno));
goto close_fd;
@@ -171,6 +157,41 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
return ret;
}
+int set_zero_hugepages(unsigned long *initial_nr_hugepages)
+{
+ int fd, ret = -1;
+ char nr_hugepages[20] = {0};
+
+ fd = open("/proc/sys/vm/nr_hugepages", O_RDWR | O_NONBLOCK);
+ if (fd < 0) {
+ ksft_print_msg("Failed to open /proc/sys/vm/nr_hugepages: %s\n",
+ strerror(errno));
+ goto out;
+ }
+ if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
+ ksft_print_msg("Failed to read from /proc/sys/vm/nr_hugepages: %s\n",
+ strerror(errno));
+ goto close_fd;
+ }
+
+ lseek(fd, 0, SEEK_SET);
+
+ /* Start with the initial condition of 0 huge pages */
+ if (write(fd, "0", sizeof(char)) != sizeof(char)) {
+ ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n",
+ strerror(errno));
+ goto close_fd;
+ }
+
+ *initial_nr_hugepages = strtoul(nr_hugepages, NULL, 10);
+ ret = 0;
+
+ close_fd:
+ close(fd);
+
+ out:
+ return ret;
+}
int main(int argc, char **argv)
{
@@ -181,6 +202,7 @@ int main(int argc, char **argv)
unsigned long mem_free = 0;
unsigned long hugepage_size = 0;
long mem_fragmentable_MB = 0;
+ unsigned long initial_nr_hugepages;
ksft_print_header();
@@ -189,6 +211,10 @@ int main(int argc, char **argv)
ksft_set_plan(1);
+ /* Start the test without hugepages reducing mem_free */
+ if (set_zero_hugepages(&initial_nr_hugepages))
+ ksft_exit_fail();
+
lim.rlim_cur = RLIM_INFINITY;
lim.rlim_max = RLIM_INFINITY;
if (setrlimit(RLIMIT_MEMLOCK, &lim))
@@ -232,7 +258,8 @@ int main(int argc, char **argv)
entry = entry->next;
}
- if (check_compaction(mem_free, hugepage_size) == 0)
+ if (check_compaction(mem_free, hugepage_size,
+ initial_nr_hugepages) == 0)
ksft_exit_pass();
ksft_exit_fail();
--
2.34.1
Currently, the test tries to set nr_hugepages to zero, but that is not
actually done because the file offset is not reset after read(). Fix that
using lseek().
Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dev Jain <dev.jain(a)arm.com>
---
tools/testing/selftests/mm/compaction_test.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 0b249a06a60b..5e9bd1da9370 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -108,6 +108,8 @@ int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
goto close_fd;
}
+ lseek(fd, 0, SEEK_SET);
+
/* Start with the initial condition of 0 huge pages*/
if (write(fd, "0", sizeof(char)) != sizeof(char)) {
ksft_print_msg("Failed to write 0 to /proc/sys/vm/nr_hugepages: %s\n",
--
2.34.1
Currently, if at runtime we are not able to allocate a huge page, the
test will trivially pass on Aarch64 due to no exception being raised on
division by zero while computing compaction_index. Fix that by checking
for nr_hugepages == 0. Anyways, in general, avoid a division by zero by
exiting the program beforehand. While at it, fix a typo, and handle the
case where the number of hugepages may overflow an integer.
Changes in v2:
- Combine with this series, handle unsigned long number of hugepages
v1:
- https://lore.kernel.org/all/20240513082842.4117782-1-dev.jain@arm.com/
Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dev Jain <dev.jain(a)arm.com>
---
tools/testing/selftests/mm/compaction_test.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 4f42eb7d7636..0b249a06a60b 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -82,12 +82,13 @@ int prereq(void)
return -1;
}
-int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
+int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
{
+ unsigned long nr_hugepages_ul;
int fd, ret = -1;
int compaction_index = 0;
- char initial_nr_hugepages[10] = {0};
- char nr_hugepages[10] = {0};
+ char initial_nr_hugepages[20] = {0};
+ char nr_hugepages[20] = {0};
/* We want to test with 80% of available memory. Else, OOM killer comes
in to play */
@@ -134,7 +135,12 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
/* We should have been able to request at least 1/3 rd of the memory in
huge pages */
- compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size);
+ nr_hugepages_ul = strtoul(nr_hugepages, NULL, 10);
+ if (!nr_hugepages_ul) {
+ ksft_print_msg("ERROR: No memory is available as huge pages\n");
+ goto close_fd;
+ }
+ compaction_index = mem_free/(nr_hugepages_ul * hugepage_size);
lseek(fd, 0, SEEK_SET);
@@ -145,11 +151,11 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
goto close_fd;
}
- ksft_print_msg("Number of huge pages allocated = %d\n",
- atoi(nr_hugepages));
+ ksft_print_msg("Number of huge pages allocated = %lu\n",
+ nr_hugepages_ul);
if (compaction_index > 3) {
- ksft_print_msg("ERROR: Less that 1/%d of memory is available\n"
+ ksft_print_msg("ERROR: Less than 1/%d of memory is available\n"
"as huge pages\n", compaction_index);
goto close_fd;
}
--
2.34.1
Currently, if at runtime we are not able to allocate a huge page, the
test will trivially pass on Aarch64 due to no exception being raised on
division by zero while computing compaction_index. Fix that by checking
for nr_hugepages == 0. Anyways, in general, avoid a division by zero by
exiting the program beforehand. While at it, fix a typo.
Changes in v2:
- Combine with this series, handle unsigned long number of hugepages
Fixes: bd67d5c15cc1 ("Test compaction of mlocked memory")
Cc: stable(a)vger.kernel.org
Signed-off-by: Dev Jain <dev.jain(a)arm.com>
---
tools/testing/selftests/mm/compaction_test.c | 20 +++++++++++++-------
1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/mm/compaction_test.c b/tools/testing/selftests/mm/compaction_test.c
index 4f42eb7d7636..0b249a06a60b 100644
--- a/tools/testing/selftests/mm/compaction_test.c
+++ b/tools/testing/selftests/mm/compaction_test.c
@@ -82,12 +82,13 @@ int prereq(void)
return -1;
}
-int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
+int check_compaction(unsigned long mem_free, unsigned long hugepage_size)
{
+ unsigned long nr_hugepages_ul;
int fd, ret = -1;
int compaction_index = 0;
- char initial_nr_hugepages[10] = {0};
- char nr_hugepages[10] = {0};
+ char initial_nr_hugepages[20] = {0};
+ char nr_hugepages[20] = {0};
/* We want to test with 80% of available memory. Else, OOM killer comes
in to play */
@@ -134,7 +135,12 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
/* We should have been able to request at least 1/3 rd of the memory in
huge pages */
- compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size);
+ nr_hugepages_ul = strtoul(nr_hugepages, NULL, 10);
+ if (!nr_hugepages_ul) {
+ ksft_print_msg("ERROR: No memory is available as huge pages\n");
+ goto close_fd;
+ }
+ compaction_index = mem_free/(nr_hugepages_ul * hugepage_size);
lseek(fd, 0, SEEK_SET);
@@ -145,11 +151,11 @@ int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
goto close_fd;
}
- ksft_print_msg("Number of huge pages allocated = %d\n",
- atoi(nr_hugepages));
+ ksft_print_msg("Number of huge pages allocated = %lu\n",
+ nr_hugepages_ul);
if (compaction_index > 3) {
- ksft_print_msg("ERROR: Less that 1/%d of memory is available\n"
+ ksft_print_msg("ERROR: Less than 1/%d of memory is available\n"
"as huge pages\n", compaction_index);
goto close_fd;
}
--
2.34.1
In some scenarios, the DPT object gets shrunk but
the actual framebuffer did not and thus its still
there on the DPT's vm->bound_list. Then it tries to
rewrite the PTEs via a stale CPU mapping. This causes panic.
Credits-to: Ville Syrjala <ville.syrjala(a)linux.intel.com>
Shawn Lee <shawn.c.lee(a)intel.com>
Cc: stable(a)vger.kernel.org
Fixes: 0dc987b699ce ("drm/i915/display: Add smem fallback allocation for dpt")
Signed-off-by: Vidya Srinivas <vidya.srinivas(a)intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_object.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 3560a062d287..e6b485fc54d4 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -284,7 +284,8 @@ bool i915_gem_object_has_iomem(const struct drm_i915_gem_object *obj);
static inline bool
i915_gem_object_is_shrinkable(const struct drm_i915_gem_object *obj)
{
- return i915_gem_object_type_has(obj, I915_GEM_OBJECT_IS_SHRINKABLE);
+ return i915_gem_object_type_has(obj, I915_GEM_OBJECT_IS_SHRINKABLE) &&
+ !obj->is_dpt;
}
static inline bool
--
2.34.1
When asn1_encode_sequence() fails, WARN is not the correct solution.
1. asn1_encode_sequence() is not an internal function (located
in lib/asn1_encode.c).
2. Location is known, which makes the stack trace useless.
3. Results a crash if panic_on_warn is set.
It is also noteworthy that the use of WARN is undocumented, and it
should be avoided unless there is a carefully considered rationale to
use it.
Replace WARN with pr_err, and print the return value instead, which is
only useful piece of information.
Cc: stable(a)vger.kernel.org # v5.13+
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Signed-off-by: Jarkko Sakkinen <jarkko(a)kernel.org>
---
security/keys/trusted-keys/trusted_tpm2.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index c6882f5d094f..8b7dd73d94c1 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -84,8 +84,9 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
+ if (IS_ERR(work1)) {
ret = PTR_ERR(work1);
+ pr_err("BUG: ASN.1 encoder failed with %d\n", ret);
goto err;
}
--
2.45.1