Attachment 188843 Details for Bug 224350 – Patch for this bug

[patch] Patch for this bug

0001-powerpc64-Add-handler-for-Facility-Unavailable.patch (text/plain), 2.53 KB, created by Gustavo Romero on 2017-12-14 22:29:28 UTC

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Creator: Gustavo Romero

Created: 2017-12-14 22:29:28 UTC

Size: 2.53 KB

patch

obsolete

>From c935b4a72dccd14ddb6fec2a279bef53d54df754 Mon Sep 17 00:00:00 2001
>From: Gustavo Romero <gromero@br.ibm.com>
>Date: Thu, 14 Dec 2017 23:12:47 +0100
>Subject: [PATCH] powerpc64: Add handler for Facility Unavailable
>
>Currently Facility Unavailable is absent and once an application
>tries to use or access a register from a feature disabled in the
>CPU it causes a kernel panic.
>
>A simple test-case is:
>
>int main() { asm volatile ("tbegin.;"); }
>
>which will use TM (Hardware Transactional Memory) feature which
>is not supported by the kernel and so will trigger the following
>kernel panic:
>
>----
>
>fatal user trap:
>
>   exception       = 0xf60 (unknown)
>   srr0            = 0x10000890
>   srr1            = 0x800000000000f032
>   lr              = 0x100004e4
>   curthread       = 0x5f93000
>          pid = 1021, comm = htm
>
>panic: unknown trap
>cpuid = 40
>KDB: stack backtrace:
>Uptime: 3m18s
>Dumping 10 MB (3 chunks)
>  chunk 0: 11MB (2648 pages) ... ok
>  chunk 1: 1MB (24 pages) ... ok
>  chunk 2: 1MB (2 pages)panic: IOMMU mapping error: -4
>
>cpuid = 40
>Uptime: 3m18s
>
>----
>
>This commit fixes that state by adding a handler for Facility
>Unavailable exception (0xF60), treating the instruction that
>trigged the exception as an illegal instruction.
>---
> sys/powerpc/include/trap.h | 3 +++
> sys/powerpc/powerpc/trap.c | 6 ++++++
> 2 files changed, 9 insertions(+)
>
>diff --git a/sys/powerpc/include/trap.h b/sys/powerpc/include/trap.h
>index 22bb0d252be..783117c4085 100644
>--- a/sys/powerpc/include/trap.h
>+++ b/sys/powerpc/include/trap.h
>@@ -80,6 +80,9 @@
> #define	EXC_HEA		0x0e40		/* Hypervisor Emulation Assistance */
> #define	EXC_VSX		0x0f40		/* VSX Unavailable */
> 
>+/* Power ISA 2.07+: */
>+#define EXC_FAC_UNA	0xF60		/* Facility Unavailable */
>+
> /* The following are available on 4xx and 85xx */
> #define	EXC_CRIT	0x0100		/* Critical Input Interrupt */
> #define	EXC_PIT		0x1000		/* Programmable Interval Timer */
>diff --git a/sys/powerpc/powerpc/trap.c b/sys/powerpc/powerpc/trap.c
>index 7c119301003..97b740cceba 100644
>--- a/sys/powerpc/powerpc/trap.c
>+++ b/sys/powerpc/powerpc/trap.c
>@@ -143,6 +143,7 @@ static struct powerpc_exception powerpc_exceptions[] = {
> 	{ EXC_VECAST_G4,	"altivec assist" },
> 	{ EXC_THRM,	"thermal management" },
> 	{ EXC_RUNMODETRC,	"run mode/trace" },
>+        { EXC_FAC_UNA,  "facility unavailable" },
> 	{ EXC_LAST,	NULL }
> };
> 
>@@ -279,6 +280,11 @@ trap(struct trapframe *frame)
> 			enable_fpu(td);
> 			break;
> 
>+		case EXC_FAC_UNA:
>+			sig = SIGILL;
>+			ucode =	ILL_ILLOPC;
>+			break;
>+
> 		case EXC_VECAST_E:
> 		case EXC_VECAST_G4:
> 		case EXC_VECAST_G5:
>-- 
>2.13.2
>

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Attachments on bug 224350: 188843