[PATCH][PPC32] Fix SPE state corruption on e500

[Kumar Gala]

Linus,

Unfortunately the restoring of SPE state was causing data corruption since 
we were restoring based on the size of the altivec context and not 
the SPE context.  Also, fixed setting of last_task_used_spe on 
start_thread, flush_thread, and exit_thread.

Patch should go in for 2.6.10.

Signed-off-by: Kumar Gala <kumar.gala@xxxxxxxxxxxxx>

--

diff -Nru a/arch/ppc/kernel/process.c b/arch/ppc/kernel/process.c
--- a/arch/ppc/kernel/process.c	2004-12-14 15:59:07 -06:00
+++ b/arch/ppc/kernel/process.c	2004-12-14 15:59:07 -06:00
@@ -321,7 +321,7 @@
 	trap = TRAP(regs);
 	if (trap == 0x300 || trap == 0x600)
 		printk("DAR: %08lX, DSISR: %08lX\n", regs->dar, regs->dsisr);
-	printk("TASK = %p[%d] '%s' THREAD: %p",
+	printk("TASK = %p[%d] '%s' THREAD: %p\n",
 	       current, current->pid, current->comm, current->thread_info);
 	printk("Last syscall: %ld ", current->thread.last_syscall);
 
@@ -370,6 +370,10 @@
 		last_task_used_math = NULL;
 	if (last_task_used_altivec == current)
 		last_task_used_altivec = NULL;
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
 }
 
 void flush_thread(void)
@@ -378,6 +382,10 @@
 		last_task_used_math = NULL;
 	if (last_task_used_altivec == current)
 		last_task_used_altivec = NULL;
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
 }
 
 void
@@ -480,6 +488,10 @@
 		last_task_used_math = NULL;
 	if (last_task_used_altivec == current)
 		last_task_used_altivec = NULL;
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
 	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
 	current->thread.fpscr = 0;
 #ifdef CONFIG_ALTIVEC
diff -Nru a/arch/ppc/kernel/signal.c b/arch/ppc/kernel/signal.c
--- a/arch/ppc/kernel/signal.c	2004-12-14 15:59:07 -06:00
+++ b/arch/ppc/kernel/signal.c	2004-12-14 15:59:07 -06:00
@@ -319,7 +319,7 @@
 	if (!__get_user(msr, &sr->mc_gregs[PT_MSR]) && (msr & MSR_SPE) != 0) {
 		/* restore spe registers from the stack */
 		if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
-				     sizeof(sr->mc_vregs)))
+				     ELF_NEVRREG * sizeof(u32)))
 			return 1;
 	} else if (current->thread.used_spe)
 		memset(&current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/