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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 13:00:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-19 13:00:23 -0700
commit62453a460a000156b100bf20ab78cf77232284d0 (patch)
tree70c73db399534c85fac1f87e17f0b15982260773
parent2f629969b01dab4ef6254fdfcfda3d82b1ad5420 (diff)
parentc006a06508db4841d256d82f42da392d6391f3d9 (diff)
Merge tag 'powerpc-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman: - Fix crashes when scv (System Call Vectored) is used to make a syscall when a transaction is active, on Power9 or later. - Fix bad interactions between rfscv (Return-from scv) and Power9 fake-suspend mode. - Fix crashes when handling machine checks in LPARs using the Hash MMU. - Partly revert a recent change to our XICS interrupt controller code, which broke the recently added Microwatt support. Thanks to Cédric Le Goater, Eirik Fuller, Ganesh Goudar, Gustavo Romero, Joel Stanley, Nicholas Piggin. * tag 'powerpc-5.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/xics: Set the IRQ chip data for the ICS native backend powerpc/mce: Fix access error in mce handler KVM: PPC: Book3S HV: Tolerate treclaim. in fake-suspend mode changing registers powerpc/64s: system call rfscv workaround for TM bugs selftests/powerpc: Add scv versions of the basic TM syscall tests powerpc/64s: system call scv tabort fix for corrupt irq soft-mask state
-rw-r--r--arch/powerpc/kernel/interrupt.c43
-rw-r--r--arch/powerpc/kernel/interrupt_64.S41
-rw-r--r--arch/powerpc/kernel/mce.c17
-rw-r--r--arch/powerpc/kvm/book3s_hv_rmhandlers.S36
-rw-r--r--arch/powerpc/sysdev/xics/xics-common.c4
-rw-r--r--tools/testing/selftests/powerpc/tm/tm-syscall-asm.S37
-rw-r--r--tools/testing/selftests/powerpc/tm/tm-syscall.c36
7 files changed, 159 insertions, 55 deletions
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index a73f3f70a657..de10a2697258 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -18,6 +18,7 @@
#include <asm/switch_to.h>
#include <asm/syscall.h>
#include <asm/time.h>
+#include <asm/tm.h>
#include <asm/unistd.h>
#if defined(CONFIG_PPC_ADV_DEBUG_REGS) && defined(CONFIG_PPC32)
@@ -136,6 +137,48 @@ notrace long system_call_exception(long r3, long r4, long r5,
*/
irq_soft_mask_regs_set_state(regs, IRQS_ENABLED);
+ /*
+ * If system call is called with TM active, set _TIF_RESTOREALL to
+ * prevent RFSCV being used to return to userspace, because POWER9
+ * TM implementation has problems with this instruction returning to
+ * transactional state. Final register values are not relevant because
+ * the transaction will be aborted upon return anyway. Or in the case
+ * of unsupported_scv SIGILL fault, the return state does not much
+ * matter because it's an edge case.
+ */
+ if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
+ unlikely(MSR_TM_TRANSACTIONAL(regs->msr)))
+ current_thread_info()->flags |= _TIF_RESTOREALL;
+
+ /*
+ * If the system call was made with a transaction active, doom it and
+ * return without performing the system call. Unless it was an
+ * unsupported scv vector, in which case it's treated like an illegal
+ * instruction.
+ */
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+ if (unlikely(MSR_TM_TRANSACTIONAL(regs->msr)) &&
+ !trap_is_unsupported_scv(regs)) {
+ /* Enable TM in the kernel, and disable EE (for scv) */
+ hard_irq_disable();
+ mtmsr(mfmsr() | MSR_TM);
+
+ /* tabort, this dooms the transaction, nothing else */
+ asm volatile(".long 0x7c00071d | ((%0) << 16)"
+ :: "r"(TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT));
+
+ /*
+ * Userspace will never see the return value. Execution will
+ * resume after the tbegin. of the aborted transaction with the
+ * checkpointed register state. A context switch could occur
+ * or signal delivered to the process before resuming the
+ * doomed transaction context, but that should all be handled
+ * as expected.
+ */
+ return -ENOSYS;
+ }
+#endif // CONFIG_PPC_TRANSACTIONAL_MEM
+
local_irq_enable();
if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) {
diff --git a/arch/powerpc/kernel/interrupt_64.S b/arch/powerpc/kernel/interrupt_64.S
index d4212d2ff0b5..ec950b08a8dc 100644
--- a/arch/powerpc/kernel/interrupt_64.S
+++ b/arch/powerpc/kernel/interrupt_64.S
@@ -12,7 +12,6 @@
#include <asm/mmu.h>
#include <asm/ppc_asm.h>
#include <asm/ptrace.h>
-#include <asm/tm.h>
.section ".toc","aw"
SYS_CALL_TABLE:
@@ -55,12 +54,6 @@ COMPAT_SYS_CALL_TABLE:
.globl system_call_vectored_\name
system_call_vectored_\name:
_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
- extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
- bne tabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
SCV_INTERRUPT_TO_KERNEL
mr r10,r1
ld r1,PACAKSAVE(r13)
@@ -247,12 +240,6 @@ _ASM_NOKPROBE_SYMBOL(system_call_common_real)
.globl system_call_common
system_call_common:
_ASM_NOKPROBE_SYMBOL(system_call_common)
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-BEGIN_FTR_SECTION
- extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
- bne tabort_syscall
-END_FTR_SECTION_IFSET(CPU_FTR_TM)
-#endif
mr r10,r1
ld r1,PACAKSAVE(r13)
std r10,0(r1)
@@ -425,34 +412,6 @@ SOFT_MASK_TABLE(.Lsyscall_rst_start, 1b)
RESTART_TABLE(.Lsyscall_rst_start, .Lsyscall_rst_end, syscall_restart)
#endif
-#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-tabort_syscall:
-_ASM_NOKPROBE_SYMBOL(tabort_syscall)
- /* Firstly we need to enable TM in the kernel */
- mfmsr r10
- li r9, 1
- rldimi r10, r9, MSR_TM_LG, 63-MSR_TM_LG
- mtmsrd r10, 0
-
- /* tabort, this dooms the transaction, nothing else */
- li r9, (TM_CAUSE_SYSCALL|TM_CAUSE_PERSISTENT)
- TABORT(R9)
-
- /*
- * Return directly to userspace. We have corrupted user register state,
- * but userspace will never see that register state. Execution will
- * resume after the tbegin of the aborted transaction with the
- * checkpointed register state.
- */
- li r9, MSR_RI
- andc r10, r10, r9
- mtmsrd r10, 1
- mtspr SPRN_SRR0, r11
- mtspr SPRN_SRR1, r12
- RFI_TO_USER
- b . /* prevent speculative execution */
-#endif
-
/*
* If MSR EE/RI was never enabled, IRQs not reconciled, NVGPRs not
* touched, no exit work created, then this can be used.
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index 47a683cd00d2..fd829f7f25a4 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -249,6 +249,7 @@ void machine_check_queue_event(void)
{
int index;
struct machine_check_event evt;
+ unsigned long msr;
if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
return;
@@ -262,8 +263,20 @@ void machine_check_queue_event(void)
memcpy(&local_paca->mce_info->mce_event_queue[index],
&evt, sizeof(evt));
- /* Queue irq work to process this event later. */
- irq_work_queue(&mce_event_process_work);
+ /*
+ * Queue irq work to process this event later. Before
+ * queuing the work enable translation for non radix LPAR,
+ * as irq_work_queue may try to access memory outside RMO
+ * region.
+ */
+ if (!radix_enabled() && firmware_has_feature(FW_FEATURE_LPAR)) {
+ msr = mfmsr();
+ mtmsr(msr | MSR_IR | MSR_DR);
+ irq_work_queue(&mce_event_process_work);
+ mtmsr(msr);
+ } else {
+ irq_work_queue(&mce_event_process_work);
+ }
}
void mce_common_process_ue(struct pt_regs *regs,
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 75079397c2a5..90484425a1e6 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -2536,7 +2536,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_P9_TM_HV_ASSIST)
/* The following code handles the fake_suspend = 1 case */
mflr r0
std r0, PPC_LR_STKOFF(r1)
- stdu r1, -PPC_MIN_STKFRM(r1)
+ stdu r1, -TM_FRAME_SIZE(r1)
/* Turn on TM. */
mfmsr r8
@@ -2551,10 +2551,42 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
nop
+ /*
+ * It's possible that treclaim. may modify registers, if we have lost
+ * track of fake-suspend state in the guest due to it using rfscv.
+ * Save and restore registers in case this occurs.
+ */
+ mfspr r3, SPRN_DSCR
+ mfspr r4, SPRN_XER
+ mfspr r5, SPRN_AMR
+ /* SPRN_TAR would need to be saved here if the kernel ever used it */
+ mfcr r12
+ SAVE_NVGPRS(r1)
+ SAVE_GPR(2, r1)
+ SAVE_GPR(3, r1)
+ SAVE_GPR(4, r1)
+ SAVE_GPR(5, r1)
+ stw r12, 8(r1)
+ std r1, HSTATE_HOST_R1(r13)
+
/* We have to treclaim here because that's the only way to do S->N */
li r3, TM_CAUSE_KVM_RESCHED
TRECLAIM(R3)
+ GET_PACA(r13)
+ ld r1, HSTATE_HOST_R1(r13)
+ REST_GPR(2, r1)
+ REST_GPR(3, r1)
+ REST_GPR(4, r1)
+ REST_GPR(5, r1)
+ lwz r12, 8(r1)
+ REST_NVGPRS(r1)
+ mtspr SPRN_DSCR, r3
+ mtspr SPRN_XER, r4
+ mtspr SPRN_AMR, r5
+ mtcr r12
+ HMT_MEDIUM
+
/*
* We were in fake suspend, so we are not going to save the
* register state as the guest checkpointed state (since
@@ -2582,7 +2614,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
std r5, VCPU_TFHAR(r9)
std r6, VCPU_TFIAR(r9)
- addi r1, r1, PPC_MIN_STKFRM
+ addi r1, r1, TM_FRAME_SIZE
ld r0, PPC_LR_STKOFF(r1)
mtlr r0
blr
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index 5c1a157a83b8..244a727c6ba4 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -348,9 +348,9 @@ static int xics_host_map(struct irq_domain *domain, unsigned int virq,
if (xics_ics->check(xics_ics, hwirq))
return -EINVAL;
- /* No chip data for the XICS domain */
+ /* Let the ICS be the chip data for the XICS domain. For ICS native */
irq_domain_set_info(domain, virq, hwirq, xics_ics->chip,
- NULL, handle_fasteoi_irq, NULL, NULL);
+ xics_ics, handle_fasteoi_irq, NULL, NULL);
return 0;
}
diff --git a/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S b/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S
index bd1ca25febe4..aed632d29fff 100644
--- a/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S
+++ b/tools/testing/selftests/powerpc/tm/tm-syscall-asm.S
@@ -1,5 +1,5 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#include <ppc-asm.h>
+#include <basic_asm.h>
#include <asm/unistd.h>
.text
@@ -26,3 +26,38 @@ FUNC_START(getppid_tm_suspended)
1:
li r3, -1
blr
+
+
+.macro scv level
+ .long (0x44000001 | (\level) << 5)
+.endm
+
+FUNC_START(getppid_scv_tm_active)
+ PUSH_BASIC_STACK(0)
+ tbegin.
+ beq 1f
+ li r0, __NR_getppid
+ scv 0
+ tend.
+ POP_BASIC_STACK(0)
+ blr
+1:
+ li r3, -1
+ POP_BASIC_STACK(0)
+ blr
+
+FUNC_START(getppid_scv_tm_suspended)
+ PUSH_BASIC_STACK(0)
+ tbegin.
+ beq 1f
+ li r0, __NR_getppid
+ tsuspend.
+ scv 0
+ tresume.
+ tend.
+ POP_BASIC_STACK(0)
+ blr
+1:
+ li r3, -1
+ POP_BASIC_STACK(0)
+ blr
diff --git a/tools/testing/selftests/powerpc/tm/tm-syscall.c b/tools/testing/selftests/powerpc/tm/tm-syscall.c
index 467a6b3134b2..b763354c2eb4 100644
--- a/tools/testing/selftests/powerpc/tm/tm-syscall.c
+++ b/tools/testing/selftests/powerpc/tm/tm-syscall.c
@@ -19,23 +19,36 @@
#include "utils.h"
#include "tm.h"
+#ifndef PPC_FEATURE2_SCV
+#define PPC_FEATURE2_SCV 0x00100000 /* scv syscall */
+#endif
+
extern int getppid_tm_active(void);
extern int getppid_tm_suspended(void);
+extern int getppid_scv_tm_active(void);
+extern int getppid_scv_tm_suspended(void);
unsigned retries = 0;
#define TEST_DURATION 10 /* seconds */
-pid_t getppid_tm(bool suspend)
+pid_t getppid_tm(bool scv, bool suspend)
{
int i;
pid_t pid;
for (i = 0; i < TM_RETRIES; i++) {
- if (suspend)
- pid = getppid_tm_suspended();
- else
- pid = getppid_tm_active();
+ if (suspend) {
+ if (scv)
+ pid = getppid_scv_tm_suspended();
+ else
+ pid = getppid_tm_suspended();
+ } else {
+ if (scv)
+ pid = getppid_scv_tm_active();
+ else
+ pid = getppid_tm_active();
+ }
if (pid >= 0)
return pid;
@@ -82,15 +95,24 @@ int tm_syscall(void)
* Test a syscall within a suspended transaction and verify
* that it succeeds.
*/
- FAIL_IF(getppid_tm(true) == -1); /* Should succeed. */
+ FAIL_IF(getppid_tm(false, true) == -1); /* Should succeed. */
/*
* Test a syscall within an active transaction and verify that
* it fails with the correct failure code.
*/
- FAIL_IF(getppid_tm(false) != -1); /* Should fail... */
+ FAIL_IF(getppid_tm(false, false) != -1); /* Should fail... */
FAIL_IF(!failure_is_persistent()); /* ...persistently... */
FAIL_IF(!failure_is_syscall()); /* ...with code syscall. */
+
+ /* Now do it all again with scv if it is available. */
+ if (have_hwcap2(PPC_FEATURE2_SCV)) {
+ FAIL_IF(getppid_tm(true, true) == -1); /* Should succeed. */
+ FAIL_IF(getppid_tm(true, false) != -1); /* Should fail... */
+ FAIL_IF(!failure_is_persistent()); /* ...persistently... */
+ FAIL_IF(!failure_is_syscall()); /* ...with code syscall. */
+ }
+
gettimeofday(&now, 0);
}