powerpc fixes for 5.18 #4

- Fix the DWARF CFI in our VDSO time functions, allowing gdb to backtrace through them
    correctly.
 
  - Fix a buffer overflow in the papr_scm driver, only triggerable by hypervisor input.
 
  - A fix in the recently added QoS handling for VAS (used for communicating with
    coprocessors).
 
 Thanks to: Alan Modra, Haren Myneni, Kajol Jain, Segher Boessenkool.
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Merge tag 'powerpc-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

 - Fix the DWARF CFI in our VDSO time functions, allowing gdb to
   backtrace through them correctly.

 - Fix a buffer overflow in the papr_scm driver, only triggerable by
   hypervisor input.

 - A fix in the recently added QoS handling for VAS (used for
   communicating with coprocessors).

Thanks to Alan Modra, Haren Myneni, Kajol Jain, and Segher Boessenkool.

* tag 'powerpc-5.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE
  powerpc/vdso: Fix incorrect CFI in gettimeofday.S
  powerpc/pseries/vas: Use QoS credits from the userspace

arch/powerpc/kernel/vdso/gettimeofday.S

@@ -22,12 +22,15 @@
 .macro cvdso_call funct call_time=0
   .cfi_startproc
 	PPC_STLU	r1, -PPC_MIN_STKFRM(r1)
+  .cfi_adjust_cfa_offset PPC_MIN_STKFRM
 	mflr		r0
-  .cfi_register lr, r0
 	PPC_STLU	r1, -PPC_MIN_STKFRM(r1)
+  .cfi_adjust_cfa_offset PPC_MIN_STKFRM
 	PPC_STL		r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+  .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
 #ifdef __powerpc64__
 	PPC_STL		r2, PPC_MIN_STKFRM + STK_GOT(r1)
+  .cfi_rel_offset r2, PPC_MIN_STKFRM + STK_GOT
 #endif
 	get_datapage	r5
 	.ifeq	\call_time
@@ -39,13 +42,15 @@
 	PPC_LL		r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
 #ifdef __powerpc64__
 	PPC_LL		r2, PPC_MIN_STKFRM + STK_GOT(r1)
+  .cfi_restore r2
 #endif
 	.ifeq	\call_time
 	cmpwi		r3, 0
 	.endif
 	mtlr		r0
-  .cfi_restore lr
 	addi		r1, r1, 2 * PPC_MIN_STKFRM
+  .cfi_restore lr
+  .cfi_def_cfa_offset 0
 	crclr		so
 	.ifeq	\call_time
 	beqlr+

arch/powerpc/platforms/pseries/papr_scm.c

@@ -462,7 +462,6 @@ static int papr_scm_pmu_check_events(struct papr_scm_priv *p, struct nvdimm_pmu
 {
 	struct papr_scm_perf_stat *stat;
 	struct papr_scm_perf_stats *stats;
-	char *statid;
 	int index, rc, count;
 	u32 available_events;
 
@@ -493,14 +492,12 @@ static int papr_scm_pmu_check_events(struct papr_scm_priv *p, struct nvdimm_pmu
 
 	for (index = 0, stat = stats->scm_statistic, count = 0;
 		     index < available_events; index++, ++stat) {
-		statid = kzalloc(strlen(stat->stat_id) + 1, GFP_KERNEL);
-		if (!statid) {
+		p->nvdimm_events_map[count] = kmemdup_nul(stat->stat_id, 8, GFP_KERNEL);
+		if (!p->nvdimm_events_map[count]) {
 			rc = -ENOMEM;
 			goto out_nvdimm_events_map;
 		}
 
-		strcpy(statid, stat->stat_id);
-		p->nvdimm_events_map[count] = statid;
 		count++;
 	}
 	p->nvdimm_events_map[count] = NULL;

arch/powerpc/platforms/pseries/vas-sysfs.c

@@ -27,22 +27,31 @@ struct vas_caps_entry {
 
 /*
  * This function is used to get the notification from the drmgr when
- * QoS credits are changed. Though receiving the target total QoS
- * credits here, get the official QoS capabilities from the hypervisor.
+ * QoS credits are changed.
  */
-static ssize_t update_total_credits_trigger(struct vas_cop_feat_caps *caps,
+static ssize_t update_total_credits_store(struct vas_cop_feat_caps *caps,
 						const char *buf, size_t count)
 {
 	int err;
 	u16 creds;
 
 	err = kstrtou16(buf, 0, &creds);
+	/*
+	 * The user space interface from the management console
+	 * notifies OS with the new QoS credits and then the
+	 * hypervisor. So OS has to use this new credits value
+	 * and reconfigure VAS windows (close or reopen depends
+	 * on the credits available) instead of depending on VAS
+	 * QoS capabilities from the hypervisor.
+	 */
 	if (!err)
-		err = vas_reconfig_capabilties(caps->win_type);
+		err = vas_reconfig_capabilties(caps->win_type, creds);
 
 	if (err)
 		return -EINVAL;
 
+	pr_info("Set QoS total credits %u\n", creds);
+
 	return count;
 }
 
@@ -92,7 +101,7 @@ VAS_ATTR_RO(nr_total_credits);
 VAS_ATTR_RO(nr_used_credits);
 
 static struct vas_sysfs_entry update_total_credits_attribute =
-	__ATTR(update_total_credits, 0200, NULL, update_total_credits_trigger);
+	__ATTR(update_total_credits, 0200, NULL, update_total_credits_store);
 
 static struct attribute *vas_def_capab_attrs[] = {
 	&nr_total_credits_attribute.attr,

arch/powerpc/platforms/pseries/vas.c

@@ -779,10 +779,10 @@ static int reconfig_close_windows(struct vas_caps *vcap, int excess_creds,
  * changes. Reconfig window configurations based on the credits
  * availability from this new capabilities.
  */
-int vas_reconfig_capabilties(u8 type)
+int vas_reconfig_capabilties(u8 type, int new_nr_creds)
 {
 	struct vas_cop_feat_caps *caps;
-	int old_nr_creds, new_nr_creds;
+	int old_nr_creds;
 	struct vas_caps *vcaps;
 	int rc = 0, nr_active_wins;
 
@@ -795,12 +795,6 @@ int vas_reconfig_capabilties(u8 type)
 	caps = &vcaps->caps;
 
 	mutex_lock(&vas_pseries_mutex);
-	rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES, vcaps->feat,
-				      (u64)virt_to_phys(&hv_cop_caps));
-	if (rc)
-		goto out;
-
-	new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
 
 	old_nr_creds = atomic_read(&caps->nr_total_credits);
 
@@ -832,7 +826,6 @@ int vas_reconfig_capabilties(u8 type)
 					false);
 	}
 
-out:
 	mutex_unlock(&vas_pseries_mutex);
 	return rc;
 }
@@ -850,7 +843,7 @@ static int pseries_vas_notifier(struct notifier_block *nb,
 	struct of_reconfig_data *rd = data;
 	struct device_node *dn = rd->dn;
 	const __be32 *intserv = NULL;
-	int len, rc = 0;
+	int new_nr_creds, len, rc = 0;
 
 	if ((action == OF_RECONFIG_ATTACH_NODE) ||
 		(action == OF_RECONFIG_DETACH_NODE))
@@ -862,7 +855,15 @@ static int pseries_vas_notifier(struct notifier_block *nb,
 	if (!intserv)
 		return NOTIFY_OK;
 
-	rc = vas_reconfig_capabilties(VAS_GZIP_DEF_FEAT_TYPE);
+	rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
+					vascaps[VAS_GZIP_DEF_FEAT_TYPE].feat,
+					(u64)virt_to_phys(&hv_cop_caps));
+	if (!rc) {
+		new_nr_creds = be16_to_cpu(hv_cop_caps.target_lpar_creds);
+		rc = vas_reconfig_capabilties(VAS_GZIP_DEF_FEAT_TYPE,
+						new_nr_creds);
+	}
+
 	if (rc)
 		pr_err("Failed reconfig VAS capabilities with DLPAR\n");
 

arch/powerpc/platforms/pseries/vas.h

@@ -135,7 +135,7 @@ struct pseries_vas_window {
 };
 
 int sysfs_add_vas_caps(struct vas_cop_feat_caps *caps);
-int vas_reconfig_capabilties(u8 type);
+int vas_reconfig_capabilties(u8 type, int new_nr_creds);
 int __init sysfs_pseries_vas_init(struct vas_all_caps *vas_caps);
 
 #ifdef CONFIG_PPC_VAS