From 57ad0d4a00f5d3e80f33ba2da8d560c73d83dc22 Mon Sep 17 00:00:00 2001 From: Thomas Richter Date: Fri, 6 Mar 2026 13:50:31 +0100 Subject: [PATCH 1/2] s390/cpum_sf: Cap sampling rate to prevent lsctl exception commit fcc43a7e294f ("s390/configs: Set HZ=1000") changed the interrupt frequency of the system. On machines with heavy load and many perf event overflows, this might lead to an exception. Dmesg displays these entries: [112.242542] cpum_sf: Loading sampling controls failed: op 1 err -22 One line per CPU online. The root cause is the CPU Measurement sampling facility overflow adjustment. Whenever an overflow (too much samples per tick) occurs, the sampling rate is adjusted and increased. This was done without observing the maximum sampling rate limit. When the current sampling interval is higher than the maximum sampling rate limit, the lsctl instruction raises an exception. The error messages is the result of such an exception. Observe the upper limit when the new sampling rate is recalculated. Cc: stable@vger.kernel.org Fixes: 39d4a501a9ef ("s390/cpum_sf: Adjust sampling interval to avoid hitting sample limits") Signed-off-by: Thomas Richter Reviewed-by: Sumanth Korikkar Reviewed-by: Hendrik Brueckner Signed-off-by: Vasily Gorbik --- arch/s390/kernel/perf_cpum_sf.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index c92c29de725e..7bfeb5208177 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1168,6 +1168,7 @@ static void hw_collect_samples(struct perf_event *event, unsigned long *sdbt, static void hw_perf_event_update(struct perf_event *event, int flush_all) { unsigned long long event_overflow, sampl_overflow, num_sdb; + struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf); struct hw_perf_event *hwc = &event->hw; union hws_trailer_header prev, new; struct hws_trailer_entry *te; @@ -1247,8 +1248,11 @@ static void hw_perf_event_update(struct perf_event *event, int flush_all) * are dropped. * Slightly increase the interval to avoid hitting this limit. */ - if (event_overflow) + if (event_overflow) { SAMPL_RATE(hwc) += DIV_ROUND_UP(SAMPL_RATE(hwc), 10); + if (SAMPL_RATE(hwc) > cpuhw->qsi.max_sampl_rate) + SAMPL_RATE(hwc) = cpuhw->qsi.max_sampl_rate; + } } static inline unsigned long aux_sdb_index(struct aux_buffer *aux, From c8d46f17c2fc7d25c18e60c008928aecab26184d Mon Sep 17 00:00:00 2001 From: Harald Freudenberger Date: Thu, 19 Mar 2026 09:06:52 +0100 Subject: [PATCH 2/2] s390/zcrypt: Fix memory leak with CCA cards used as accelerator Tests showed that there is a memory leak if CCA cards are used as accelerator for clear key RSA requests (ME and CRT). With the last rework for the memory allocation the AP messages are allocated by ap_init_apmsg() but for some reason on two places (ME and CRT) the older allocation was still in place. So the first allocation simple was never freed. Fixes: 57db62a130ce ("s390/ap/zcrypt: Rework AP message buffer allocation") Reported-by: Yi Zhang Closes: https://lore.kernel.org/linux-s390/CAHj4cs9H67Uz0iVaRQv447p7JFPRPy3TKAT4=Y6_e=wSHCZM5w@mail.gmail.com/ Reported-by: Nadja Hariz Cc: stable@vger.kernel.org Reviewed-by: Ingo Franzki Reviewed-by: Holger Dengler Acked-by: Heiko Carstens Signed-off-by: Harald Freudenberger Signed-off-by: Vasily Gorbik --- drivers/s390/crypto/zcrypt_msgtype6.c | 32 ++++++++++++--------------- 1 file changed, 14 insertions(+), 18 deletions(-) diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c index a0dcab5dc4f2..23a32221e41a 100644 --- a/drivers/s390/crypto/zcrypt_msgtype6.c +++ b/drivers/s390/crypto/zcrypt_msgtype6.c @@ -953,6 +953,10 @@ static atomic_t zcrypt_step = ATOMIC_INIT(0); /* * The request distributor calls this function if it picked the CEXxC * device to handle a modexpo request. + * This function assumes that ap_msg has been initialized with + * ap_init_apmsg() and thus a valid buffer with the size of + * ap_msg->bufsize is available within ap_msg. Also the caller has + * to make sure ap_release_apmsg() is always called even on failure. * @zq: pointer to zcrypt_queue structure that identifies the * CEXxC device to the request distributor * @mex: pointer to the modexpo request buffer @@ -964,21 +968,17 @@ static long zcrypt_msgtype6_modexpo(struct zcrypt_queue *zq, struct ap_response_type *resp_type = &ap_msg->response; int rc; - ap_msg->msg = (void *)get_zeroed_page(GFP_KERNEL); - if (!ap_msg->msg) - return -ENOMEM; - ap_msg->bufsize = PAGE_SIZE; ap_msg->receive = zcrypt_msgtype6_receive; ap_msg->psmid = (((unsigned long)current->pid) << 32) + atomic_inc_return(&zcrypt_step); rc = icamex_msg_to_type6mex_msgx(zq, ap_msg, mex); if (rc) - goto out_free; + goto out; resp_type->type = CEXXC_RESPONSE_TYPE_ICA; init_completion(&resp_type->work); rc = ap_queue_message(zq->queue, ap_msg); if (rc) - goto out_free; + goto out; rc = wait_for_completion_interruptible(&resp_type->work); if (rc == 0) { rc = ap_msg->rc; @@ -991,15 +991,17 @@ static long zcrypt_msgtype6_modexpo(struct zcrypt_queue *zq, ap_cancel_message(zq->queue, ap_msg); } -out_free: - free_page((unsigned long)ap_msg->msg); - ap_msg->msg = NULL; +out: return rc; } /* * The request distributor calls this function if it picked the CEXxC * device to handle a modexpo_crt request. + * This function assumes that ap_msg has been initialized with + * ap_init_apmsg() and thus a valid buffer with the size of + * ap_msg->bufsize is available within ap_msg. Also the caller has + * to make sure ap_release_apmsg() is always called even on failure. * @zq: pointer to zcrypt_queue structure that identifies the * CEXxC device to the request distributor * @crt: pointer to the modexpoc_crt request buffer @@ -1011,21 +1013,17 @@ static long zcrypt_msgtype6_modexpo_crt(struct zcrypt_queue *zq, struct ap_response_type *resp_type = &ap_msg->response; int rc; - ap_msg->msg = (void *)get_zeroed_page(GFP_KERNEL); - if (!ap_msg->msg) - return -ENOMEM; - ap_msg->bufsize = PAGE_SIZE; ap_msg->receive = zcrypt_msgtype6_receive; ap_msg->psmid = (((unsigned long)current->pid) << 32) + atomic_inc_return(&zcrypt_step); rc = icacrt_msg_to_type6crt_msgx(zq, ap_msg, crt); if (rc) - goto out_free; + goto out; resp_type->type = CEXXC_RESPONSE_TYPE_ICA; init_completion(&resp_type->work); rc = ap_queue_message(zq->queue, ap_msg); if (rc) - goto out_free; + goto out; rc = wait_for_completion_interruptible(&resp_type->work); if (rc == 0) { rc = ap_msg->rc; @@ -1038,9 +1036,7 @@ static long zcrypt_msgtype6_modexpo_crt(struct zcrypt_queue *zq, ap_cancel_message(zq->queue, ap_msg); } -out_free: - free_page((unsigned long)ap_msg->msg); - ap_msg->msg = NULL; +out: return rc; }