From 57831bfb5e78777dc399e351ed68ef77c3aee385 Mon Sep 17 00:00:00 2001 From: Haren Myneni Date: Sat, 19 Mar 2022 02:28:09 -0700 Subject: powerpc/pseries/vas: Use QoS credits from the userspace The user can change the QoS credits dynamically with the management console interface which notifies OS with sysfs. After returning from the OS interface successfully, the management console updates the hypervisor. Since the VAS capabilities in the hypervisor is not updated when the OS gets the update, the kernel is using the old total credits value from the hypervisor. Fix this issue by using the new QoS credits from the userspace instead of depending on VAS capabilities from the hypervisor. Signed-off-by: Haren Myneni Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/76d156f8af1e03cc09369d68e0bfad0c40031bcc.camel@linux.ibm.com --- arch/powerpc/platforms/pseries/vas-sysfs.c | 19 ++++++++++++++----- arch/powerpc/platforms/pseries/vas.c | 23 ++++++++++++----------- arch/powerpc/platforms/pseries/vas.h | 2 +- 3 files changed, 27 insertions(+), 17 deletions(-) (limited to 'arch/powerpc/platforms') diff --git a/arch/powerpc/platforms/pseries/vas-sysfs.c b/arch/powerpc/platforms/pseries/vas-sysfs.c index 909535ca513a..ec65586cbeb3 100644 --- a/arch/powerpc/platforms/pseries/vas-sysfs.c +++ b/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, diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c index 1f59d78c77a1..ec643bbdb67f 100644 --- a/arch/powerpc/platforms/pseries/vas.c +++ b/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"); diff --git a/arch/powerpc/platforms/pseries/vas.h b/arch/powerpc/platforms/pseries/vas.h index 34177881e998..333ffa2f9f42 100644 --- a/arch/powerpc/platforms/pseries/vas.h +++ b/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 -- cgit v1.2.3 From 348c71344111d7a48892e3e52264ff11956fc196 Mon Sep 17 00:00:00 2001 From: Kajol Jain Date: Thu, 5 May 2022 21:04:51 +0530 Subject: powerpc/papr_scm: Fix buffer overflow issue with CONFIG_FORTIFY_SOURCE With CONFIG_FORTIFY_SOURCE enabled, string functions will also perform dynamic checks for string size which can panic the kernel, like incase of overflow detection. In papr_scm, papr_scm_pmu_check_events function uses stat->stat_id with string operations, to populate the nvdimm_events_map array. Since stat_id variable is not NULL terminated, the kernel panics with CONFIG_FORTIFY_SOURCE enabled at boot time. Below are the logs of kernel panic: detected buffer overflow in __fortify_strlen ------------[ cut here ]------------ kernel BUG at lib/string_helpers.c:980! Oops: Exception in kernel mode, sig: 5 [#1] NIP [c00000000077dad0] fortify_panic+0x28/0x38 LR [c00000000077dacc] fortify_panic+0x24/0x38 Call Trace: [c0000022d77836e0] [c00000000077dacc] fortify_panic+0x24/0x38 (unreliable) [c00800000deb2660] papr_scm_pmu_check_events.constprop.0+0x118/0x220 [papr_scm] [c00800000deb2cb0] papr_scm_probe+0x288/0x62c [papr_scm] [c0000000009b46a8] platform_probe+0x98/0x150 Fix this issue by using kmemdup_nul() to copy the content of stat->stat_id directly to the nvdimm_events_map array. mpe: stat->stat_id comes from the hypervisor, not userspace, so there is no security exposure. Fixes: 4c08d4bbc089 ("powerpc/papr_scm: Add perf interface support") Signed-off-by: Kajol Jain Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220505153451.35503-1-kjain@linux.ibm.com --- arch/powerpc/platforms/pseries/papr_scm.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'arch/powerpc/platforms') diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index f58728d5f10d..39962c905542 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/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; -- cgit v1.2.3