From 13fc6c175924eaa953cf597ce28ffa4edc4554a6 Mon Sep 17 00:00:00 2001 From: Jinglin Wen Date: Thu, 20 Jun 2024 10:41:50 +0800 Subject: powerpc/64s: Fix unnecessary copy to 0 when kernel is booted at address 0 According to the code logic, when the kernel is loaded at address 0, no copying operation should be performed, but it is currently being done. This patch fixes the issue where the kernel code was incorrectly duplicated to address 0 when booting from address 0. Fixes: b270bebd34e3 ("powerpc/64s: Run at the kernel virtual address earlier in boot") Cc: stable@vger.kernel.org # v6.4+ Signed-off-by: Jinglin Wen Suggested-by: Michael Ellerman Signed-off-by: Michael Ellerman Link: https://msgid.link/20240620024150.14857-1-jinglin.wen@shingroup.cn --- arch/powerpc/kernel/head_64.S | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 4690c219bfa4..63432a33ec49 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -647,8 +647,9 @@ __after_prom_start: * Note: This process overwrites the OF exception vectors. */ LOAD_REG_IMMEDIATE(r3, PAGE_OFFSET) - mr. r4,r26 /* In some cases the loader may */ - beq 9f /* have already put us at zero */ + mr r4,r26 /* Load the virtual source address into r4 */ + cmpld r3,r4 /* Check if source == dest */ + beq 9f /* If so skip the copy */ li r6,0x100 /* Start offset, the first 0x100 */ /* bytes were copied earlier. */ -- cgit v1.2.3-59-g8ed1b From 1a14150e1656f7a332a943154fc486504db4d586 Mon Sep 17 00:00:00 2001 From: Anjali K Date: Fri, 14 Jun 2024 23:08:44 +0530 Subject: powerpc/pseries: Whitelist dtl slub object for copying to userspace Reading the dispatch trace log from /sys/kernel/debug/powerpc/dtl/cpu-* results in a BUG() when the config CONFIG_HARDENED_USERCOPY is enabled as shown below. kernel BUG at mm/usercopy.c:102! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: xfs libcrc32c dm_service_time sd_mod t10_pi sg ibmvfc scsi_transport_fc ibmveth pseries_wdt dm_multipath dm_mirror dm_region_hash dm_log dm_mod fuse CPU: 27 PID: 1815 Comm: python3 Not tainted 6.10.0-rc3 #85 Hardware name: IBM,9040-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_042) hv:phyp pSeries NIP: c0000000005d23d4 LR: c0000000005d23d0 CTR: 00000000006ee6f8 REGS: c000000120c078c0 TRAP: 0700 Not tainted (6.10.0-rc3) MSR: 8000000000029033 CR: 2828220f XER: 0000000e CFAR: c0000000001fdc80 IRQMASK: 0 [ ... GPRs omitted ... ] NIP [c0000000005d23d4] usercopy_abort+0x78/0xb0 LR [c0000000005d23d0] usercopy_abort+0x74/0xb0 Call Trace: usercopy_abort+0x74/0xb0 (unreliable) __check_heap_object+0xf8/0x120 check_heap_object+0x218/0x240 __check_object_size+0x84/0x1a4 dtl_file_read+0x17c/0x2c4 full_proxy_read+0x8c/0x110 vfs_read+0xdc/0x3a0 ksys_read+0x84/0x144 system_call_exception+0x124/0x330 system_call_vectored_common+0x15c/0x2ec --- interrupt: 3000 at 0x7fff81f3ab34 Commit 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0") requires that only whitelisted areas in slab/slub objects can be copied to userspace when usercopy hardening is enabled using CONFIG_HARDENED_USERCOPY. Dtl contains hypervisor dispatch events which are expected to be read by privileged users. Hence mark this safe for user access. Specify useroffset=0 and usersize=DISPATCH_LOG_BYTES to whitelist the entire object. Co-developed-by: Vishal Chourasia Signed-off-by: Vishal Chourasia Signed-off-by: Anjali K Reviewed-by: Srikar Dronamraju Signed-off-by: Michael Ellerman Link: https://msgid.link/20240614173844.746818-1-anjalik@linux.ibm.com --- arch/powerpc/platforms/pseries/setup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index 284a6fa04b0c..cba40d9d1284 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -343,8 +343,8 @@ static int alloc_dispatch_log_kmem_cache(void) { void (*ctor)(void *) = get_dtl_cache_ctor(); - dtl_cache = kmem_cache_create("dtl", DISPATCH_LOG_BYTES, - DISPATCH_LOG_BYTES, 0, ctor); + dtl_cache = kmem_cache_create_usercopy("dtl", DISPATCH_LOG_BYTES, + DISPATCH_LOG_BYTES, 0, 0, DISPATCH_LOG_BYTES, ctor); if (!dtl_cache) { pr_warn("Failed to create dispatch trace log buffer cache\n"); pr_warn("Stolen time statistics will be unreliable\n"); -- cgit v1.2.3-59-g8ed1b From a1216e62d039bf63a539bbe718536ec789a853dd Mon Sep 17 00:00:00 2001 From: Ganesh Goudar Date: Mon, 17 Jun 2024 19:32:40 +0530 Subject: powerpc/eeh: avoid possible crash when edev->pdev changes If a PCI device is removed during eeh_pe_report_edev(), edev->pdev will change and can cause a crash, hold the PCI rescan/remove lock while taking a copy of edev->pdev->bus. Signed-off-by: Ganesh Goudar Signed-off-by: Michael Ellerman Link: https://msgid.link/20240617140240.580453-1-ganeshgr@linux.ibm.com --- arch/powerpc/kernel/eeh_pe.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c index d1030bc52564..d283d281d28e 100644 --- a/arch/powerpc/kernel/eeh_pe.c +++ b/arch/powerpc/kernel/eeh_pe.c @@ -849,6 +849,7 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) { struct eeh_dev *edev; struct pci_dev *pdev; + struct pci_bus *bus = NULL; if (pe->type & EEH_PE_PHB) return pe->phb->bus; @@ -859,9 +860,11 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe) /* Retrieve the parent PCI bus of first (top) PCI device */ edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry); + pci_lock_rescan_remove(); pdev = eeh_dev_to_pci_dev(edev); if (pdev) - return pdev->bus; + bus = pdev->bus; + pci_unlock_rescan_remove(); - return NULL; + return bus; } -- cgit v1.2.3-59-g8ed1b From 21a741eb75f80397e5f7d3739e24d7d75e619011 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 25 Jun 2024 23:40:47 +1000 Subject: powerpc/pseries: Fix scv instruction crash with kexec kexec on pseries disables AIL (reloc_on_exc), required for scv instruction support, before other CPUs have been shut down. This means they can execute scv instructions after AIL is disabled, which causes an interrupt at an unexpected entry location that crashes the kernel. Change the kexec sequence to disable AIL after other CPUs have been brought down. As a refresher, the real-mode scv interrupt vector is 0x17000, and the fixed-location head code probably couldn't easily deal with implementing such high addresses so it was just decided not to support that interrupt at all. Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable@vger.kernel.org # v5.9+ Reported-by: Sourabh Jain Closes: https://lore.kernel.org/3b4b2943-49ad-4619-b195-bc416f1d1409@linux.ibm.com Signed-off-by: Nicholas Piggin Tested-by: Gautam Menghani Tested-by: Sourabh Jain Link: https://msgid.link/20240625134047.298759-1-npiggin@gmail.com Signed-off-by: Michael Ellerman --- arch/powerpc/kexec/core_64.c | 11 +++++++++++ arch/powerpc/platforms/pseries/kexec.c | 8 -------- arch/powerpc/platforms/pseries/pseries.h | 1 - arch/powerpc/platforms/pseries/setup.c | 1 - 4 files changed, 11 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c index 85050be08a23..72b12bc10f90 100644 --- a/arch/powerpc/kexec/core_64.c +++ b/arch/powerpc/kexec/core_64.c @@ -27,6 +27,7 @@ #include #include #include /* _end */ +#include #include #include #include @@ -317,6 +318,16 @@ void default_machine_kexec(struct kimage *image) if (!kdump_in_progress()) kexec_prepare_cpus(); +#ifdef CONFIG_PPC_PSERIES + /* + * This must be done after other CPUs have shut down, otherwise they + * could execute the 'scv' instruction, which is not supported with + * reloc disabled (see configure_exceptions()). + */ + if (firmware_has_feature(FW_FEATURE_SET_MODE)) + pseries_disable_reloc_on_exc(); +#endif + printk("kexec: Starting switchover sequence.\n"); /* switch to a staticly allocated stack. Based on irq stack code. diff --git a/arch/powerpc/platforms/pseries/kexec.c b/arch/powerpc/platforms/pseries/kexec.c index 096d09ed89f6..431be156ca9b 100644 --- a/arch/powerpc/platforms/pseries/kexec.c +++ b/arch/powerpc/platforms/pseries/kexec.c @@ -61,11 +61,3 @@ void pseries_kexec_cpu_down(int crash_shutdown, int secondary) } else xics_kexec_teardown_cpu(secondary); } - -void pseries_machine_kexec(struct kimage *image) -{ - if (firmware_has_feature(FW_FEATURE_SET_MODE)) - pseries_disable_reloc_on_exc(); - - default_machine_kexec(image); -} diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h index bba4ad192b0f..3968a6970fa8 100644 --- a/arch/powerpc/platforms/pseries/pseries.h +++ b/arch/powerpc/platforms/pseries/pseries.h @@ -38,7 +38,6 @@ static inline void smp_init_pseries(void) { } #endif extern void pseries_kexec_cpu_down(int crash_shutdown, int secondary); -void pseries_machine_kexec(struct kimage *image); extern void pSeries_final_fixup(void); diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c index cba40d9d1284..b10a25325238 100644 --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -1159,7 +1159,6 @@ define_machine(pseries) { .machine_check_exception = pSeries_machine_check_exception, .machine_check_log_err = pSeries_machine_check_log_err, #ifdef CONFIG_KEXEC_CORE - .machine_kexec = pseries_machine_kexec, .kexec_cpu_down = pseries_kexec_cpu_down, #endif #ifdef CONFIG_MEMORY_HOTPLUG -- cgit v1.2.3-59-g8ed1b From 8b7f59de92ac65aa21c7d779274dbfa577ae2d2c Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sat, 6 Jul 2024 22:08:33 +1000 Subject: selftests/powerpc: Fix build with USERCFLAGS set Currently building the powerpc selftests with USERCFLAGS set to anything causes the build to break: $ make -C tools/testing/selftests/powerpc V=1 USERCFLAGS=-Wno-error ... gcc -Wno-error cache_shape.c ... cache_shape.c:18:10: fatal error: utils.h: No such file or directory 18 | #include "utils.h" | ^~~~~~~~~ compilation terminated. This happens because the USERCFLAGS are added to CFLAGS in lib.mk, which causes the check of CFLAGS in powerpc/flags.mk to skip setting CFLAGS at all, resulting in none of the usual CFLAGS being passed. That can be seen in the output above, the only flag passed to the compiler is -Wno-error. Fix it by dropping the conditional setting of CFLAGS in flags.mk. Instead always set CFLAGS, but also append USERCFLAGS if they are set. Note that appending to CFLAGS (with +=) wouldn't work, because flags.mk is included by multiple Makefiles (to support partial builds), causing CFLAGS to be appended to multiple times. Additionally that would place the USERCFLAGS prior to the standard CFLAGS, meaning the USERCFLAGS couldn't override the standard flags. Being able to override the standard flags is desirable, for example for adding -Wno-error. With the fix in place, the CFLAGS are set correctly, including the USERCFLAGS: $ make -C tools/testing/selftests/powerpc V=1 USERCFLAGS=-Wno-error ... gcc -std=gnu99 -O2 -Wall -Werror -DGIT_VERSION='"v6.10-rc2-7-gdea17e7e56c3"' -I/home/michael/linux/tools/testing/selftests/powerpc/include -Wno-error cache_shape.c ... Fixes: 5553a79387e9 ("selftests/powerpc: Add flags.mk to support pmu buildable") Signed-off-by: Michael Ellerman Link: https://msgid.link/20240706120833.909853-1-mpe@ellerman.id.au --- tools/testing/selftests/powerpc/flags.mk | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/tools/testing/selftests/powerpc/flags.mk b/tools/testing/selftests/powerpc/flags.mk index b909bee3cb2a..abb9e58d95c4 100644 --- a/tools/testing/selftests/powerpc/flags.mk +++ b/tools/testing/selftests/powerpc/flags.mk @@ -5,8 +5,5 @@ GIT_VERSION := $(shell git describe --always --long --dirty || echo "unknown") export GIT_VERSION endif -ifeq ($(CFLAGS),) -CFLAGS := -std=gnu99 -O2 -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(selfdir)/powerpc/include $(CFLAGS) +CFLAGS := -std=gnu99 -O2 -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(selfdir)/powerpc/include $(USERCFLAGS) export CFLAGS -endif - -- cgit v1.2.3-59-g8ed1b