Merge tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "A bit of a big batch, partly because I didn't send any last week, and
  also just because the BPF fixes happened to land this week.

  Summary:

   - Fix a regression hit by the IPR SCSI driver, introduced by the
     recent addition of MSI domains on pseries.

   - A big series including 8 BPF fixes, some with potential security
     impact and the rest various code generation issues.

   - Fix our program check assembler entry path, which was accidentally
     jumping into a gas macro and generating strange stack frames, which
     could confuse find_bug().

   - A couple of fixes, and related changes, to fix corner cases in our
     machine check handling.

   - Fix our DMA IOMMU ops, which were not always returning the optimal
     DMA mask, leading to at least one device falling back to 32-bit DMA
     when it shouldn't.

   - A fix for KUAP handling on 32-bit Book3S.

   - Fix crashes seen when kdumping on some pseries systems.

  Thanks to Naveen N. Rao, Nicholas Piggin, Alexey Kardashevskiy, Cédric
  Le Goater, Christophe Leroy, Mahesh Salgaonkar, Abdul Haleem,
  Christoph Hellwig, Johan Almbladh, Stan Johnson"

* tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init
  powerpc/32s: Fix kuap_kernel_restore()
  powerpc/pseries/msi: Add an empty irq_write_msi_msg() handler
  powerpc/64s: Fix unrecoverable MCE calling async handler from NMI
  powerpc/64/interrupt: Reconcile soft-mask state in NMI and fix false BUG
  powerpc/64: warn if local irqs are enabled in NMI or hardirq context
  powerpc/traps: do not enable irqs in _exception
  powerpc/64s: fix program check interrupt emergency stack path
  powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000
  powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END
  powerpc/bpf ppc32: Fix JMP32_JSET_K
  powerpc/bpf ppc32: Fix ALU32 BPF_ARSH operation
  powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC
  powerpc/security: Add a helper to query stf_barrier type
  powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
  powerpc/bpf: Fix BPF_MOD when imm == 1
  powerpc/bpf: Validate branch ranges
  powerpc/lib: Add helper to check if offset is within conditional branch range
  powerpc/iommu: Report the correct most efficient DMA mask for PCI devices

5 files changed, 63 insertions, 25 deletions

diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 111249fd619d..038ce8d9061d 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -184,6 +184,15 @@ u64 dma_iommu_get_required_mask(struct device *dev)
 	struct iommu_table *tbl = get_iommu_table_base(dev);
 	u64 mask;
 
+	if (dev_is_pci(dev)) {
+		u64 bypass_mask = dma_direct_get_required_mask(dev);
+
+		if (dma_iommu_dma_supported(dev, bypass_mask)) {
+			dev_info(dev, "%s: returning bypass mask 0x%llx\n", __func__, bypass_mask);
+			return bypass_mask;
+		}
+	}
+
 	if (!tbl)
 		return 0;
 
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 37859e62a8dc..eaf1f72131a1 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1243,7 +1243,7 @@ EXC_COMMON_BEGIN(machine_check_common)
 	li	r10,MSR_RI
 	mtmsrd 	r10,1
 	addi	r3,r1,STACK_FRAME_OVERHEAD
-	bl	machine_check_exception
+	bl	machine_check_exception_async
 	b	interrupt_return_srr
 
 
@@ -1303,7 +1303,11 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
 	subi	r12,r12,1
 	sth	r12,PACA_IN_MCE(r13)
 
-	/* Invoke machine_check_exception to print MCE event and panic. */
+	/*
+	 * Invoke machine_check_exception to print MCE event and panic.
+	 * This is the NMI version of the handler because we are called from
+	 * the early handler which is a true NMI.
+	 */
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	machine_check_exception
 
@@ -1665,27 +1669,30 @@ EXC_COMMON_BEGIN(program_check_common)
 	 */
 
 	andi.	r10,r12,MSR_PR
-	bne	2f			/* If userspace, go normal path */
+	bne	.Lnormal_stack		/* If userspace, go normal path */
 
 	andis.	r10,r12,(SRR1_PROGTM)@h
-	bne	1f			/* If TM, emergency		*/
+	bne	.Lemergency_stack	/* If TM, emergency		*/
 
 	cmpdi	r1,-INT_FRAME_SIZE	/* check if r1 is in userspace	*/
-	blt	2f			/* normal path if not		*/
+	blt	.Lnormal_stack		/* normal path if not		*/
 
 	/* Use the emergency stack					*/
-1:	andi.	r10,r12,MSR_PR		/* Set CR0 correctly for label	*/
+.Lemergency_stack:
+	andi.	r10,r12,MSR_PR		/* Set CR0 correctly for label	*/
 					/* 3 in EXCEPTION_PROLOG_COMMON	*/
 	mr	r10,r1			/* Save r1			*/
 	ld	r1,PACAEMERGSP(r13)	/* Use emergency stack		*/
 	subi	r1,r1,INT_FRAME_SIZE	/* alloc stack frame		*/
 	__ISTACK(program_check)=0
 	__GEN_COMMON_BODY program_check
-	b 3f
-2:
+	b .Ldo_program_check
+
+.Lnormal_stack:
 	__ISTACK(program_check)=1
 	__GEN_COMMON_BODY program_check
-3:
+
+.Ldo_program_check:
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	bl	program_check_exception
 	REST_NVGPRS(r1) /* instruction emulation may change GPRs */
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 551b653228c4..c4f1d6b7d992 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -229,6 +229,9 @@ notrace void arch_local_irq_restore(unsigned long mask)
 		return;
 	}
 
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(in_nmi() || in_hardirq());
+
 	/*
 	 * After the stb, interrupts are unmasked and there are no interrupts
 	 * pending replay. The restart sequence makes this atomic with
@@ -321,6 +324,9 @@ notrace void arch_local_irq_restore(unsigned long mask)
 	if (mask)
 		return;
 
+	if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
+		WARN_ON_ONCE(in_nmi() || in_hardirq());
+
 	/*
 	 * From this point onward, we can take interrupts, preempt,
 	 * etc... unless we got hard-disabled. We check if an event
diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index 1a998490fe60..15fb5ea1b9ea 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -263,6 +263,11 @@ static int __init handle_no_stf_barrier(char *p)
 
 early_param("no_stf_barrier", handle_no_stf_barrier);
 
+enum stf_barrier_type stf_barrier_type_get(void)
+{
+	return stf_enabled_flush_types;
+}
+
 /* This is the generic flag used by other architectures */
 static int __init handle_ssbd(char *p)
 {
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index aac8c0412ff9..11741703d26e 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -340,10 +340,16 @@ static bool exception_common(int signr, struct pt_regs *regs, int code,
 		return false;
 	}
 
-	show_signal_msg(signr, regs, code, addr);
+	/*
+	 * Must not enable interrupts even for user-mode exception, because
+	 * this can be called from machine check, which may be a NMI or IRQ
+	 * which don't like interrupts being enabled. Could check for
+	 * in_hardirq || in_nmi perhaps, but there doesn't seem to be a good
+	 * reason why _exception() should enable irqs for an exception handler,
+	 * the handlers themselves do that directly.
+	 */
 
-	if (arch_irqs_disabled())
-		interrupt_cond_local_irq_enable(regs);
+	show_signal_msg(signr, regs, code, addr);
 
 	current->thread.trap_nr = code;
 
@@ -790,24 +796,22 @@ void die_mce(const char *str, struct pt_regs *regs, long err)
 	 * do_exit() checks for in_interrupt() and panics in that case, so
 	 * exit the irq/nmi before calling die.
 	 */
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
-		irq_exit();
-	else
+	if (in_nmi())
 		nmi_exit();
+	else
+		irq_exit();
 	die(str, regs, err);
 }
 
 /*
- * BOOK3S_64 does not call this handler as a non-maskable interrupt
+ * BOOK3S_64 does not usually call this handler as a non-maskable interrupt
  * (it uses its own early real-mode handler to handle the MCE proper
  * and then raises irq_work to call this handler when interrupts are
- * enabled).
+ * enabled). The only time when this is not true is if the early handler
+ * is unrecoverable, then it does call this directly to try to get a
+ * message out.
  */
-#ifdef CONFIG_PPC_BOOK3S_64
-DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception)
-#else
-DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
-#endif
+static void __machine_check_exception(struct pt_regs *regs)
 {
 	int recover = 0;
 
@@ -841,12 +845,19 @@ bail:
 	/* Must die if the interrupt is not recoverable */
 	if (regs_is_unrecoverable(regs))
 		die_mce("Unrecoverable Machine check", regs, SIGBUS);
+}
 
 #ifdef CONFIG_PPC_BOOK3S_64
-	return;
-#else
-	return 0;
+DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception_async)
+{
+	__machine_check_exception(regs);
+}
 #endif
+DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
+{
+	__machine_check_exception(regs);
+
+	return 0;
 }
 
 DEFINE_INTERRUPT_HANDLER(SMIException) /* async? */