From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/arch/s390/mm/maccess.c | 68 +++++++++++++++++++++++++--------
1 files changed, 51 insertions(+), 17 deletions(-)
diff --git a/kernel/arch/s390/mm/maccess.c b/kernel/arch/s390/mm/maccess.c
index 7be0647..1d17413 100644
--- a/kernel/arch/s390/mm/maccess.c
+++ b/kernel/arch/s390/mm/maccess.c
@@ -16,6 +16,7 @@
#include <linux/cpu.h>
#include <asm/ctl_reg.h>
#include <asm/io.h>
+#include <asm/stacktrace.h>
static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
{
@@ -51,24 +52,32 @@
* Therefore we have a read-modify-write sequence: the function reads eight
* bytes from destination at an eight byte boundary, modifies the bytes
* requested and writes the result back in a loop.
- *
- * Note: this means that this function may not be called concurrently on
- * several cpus with overlapping words, since this may potentially
- * cause data corruption.
*/
-void notrace s390_kernel_write(void *dst, const void *src, size_t size)
+static DEFINE_SPINLOCK(s390_kernel_write_lock);
+
+notrace void *s390_kernel_write(void *dst, const void *src, size_t size)
{
+ void *tmp = dst;
+ unsigned long flags;
long copied;
- while (size) {
- copied = s390_kernel_write_odd(dst, src, size);
- dst += copied;
- src += copied;
- size -= copied;
+ spin_lock_irqsave(&s390_kernel_write_lock, flags);
+ if (!(flags & PSW_MASK_DAT)) {
+ memcpy(dst, src, size);
+ } else {
+ while (size) {
+ copied = s390_kernel_write_odd(tmp, src, size);
+ tmp += copied;
+ src += copied;
+ size -= copied;
+ }
}
+ spin_unlock_irqrestore(&s390_kernel_write_lock, flags);
+
+ return dst;
}
-static int __memcpy_real(void *dest, void *src, size_t count)
+static int __no_sanitize_address __memcpy_real(void *dest, void *src, size_t count)
{
register unsigned long _dest asm("2") = (unsigned long) dest;
register unsigned long _len1 asm("3") = (unsigned long) count;
@@ -89,21 +98,23 @@
return rc;
}
-/*
- * Copy memory in real mode (kernel to kernel)
- */
-int memcpy_real(void *dest, void *src, size_t count)
+static unsigned long __no_sanitize_address _memcpy_real(unsigned long dest,
+ unsigned long src,
+ unsigned long count)
{
int irqs_disabled, rc;
unsigned long flags;
if (!count)
return 0;
- flags = __arch_local_irq_stnsm(0xf8UL);
+ flags = arch_local_irq_save();
irqs_disabled = arch_irqs_disabled_flags(flags);
if (!irqs_disabled)
trace_hardirqs_off();
- rc = __memcpy_real(dest, src, count);
+ __arch_local_irq_stnsm(0xf8); // disable DAT
+ rc = __memcpy_real((void *) dest, (void *) src, (size_t) count);
+ if (flags & PSW_MASK_DAT)
+ __arch_local_irq_stosm(0x04); // enable DAT
if (!irqs_disabled)
trace_hardirqs_on();
__arch_local_irq_ssm(flags);
@@ -111,6 +122,29 @@
}
/*
+ * Copy memory in real mode (kernel to kernel)
+ */
+int memcpy_real(void *dest, void *src, size_t count)
+{
+ int rc;
+
+ if (S390_lowcore.nodat_stack != 0) {
+ preempt_disable();
+ rc = CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack, 3,
+ dest, src, count);
+ preempt_enable();
+ return rc;
+ }
+ /*
+ * This is a really early memcpy_real call, the stacks are
+ * not set up yet. Just call _memcpy_real on the early boot
+ * stack
+ */
+ return _memcpy_real((unsigned long) dest,(unsigned long) src,
+ (unsigned long) count);
+}
+
+/*
* Copy memory in absolute mode (kernel to kernel)
*/
void memcpy_absolute(void *dest, void *src, size_t count)
--
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