2021-04-01 18:46:32

by Thomas Bogendoerfer

[permalink] [raw]
Subject: [PATCH v3 2/4] MIPS: uaccess: Added __get/__put_kernel_nofault

Added __get/__put_kernel_nofault as preparation for removing
get/set_fs.

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Thomas Bogendoerfer <[email protected]>
---
arch/mips/include/asm/uaccess.h | 24 ++++++++++++++++++++++++
arch/mips/mm/Makefile | 4 ++++
arch/mips/mm/maccess.c | 10 ++++++++++
3 files changed, 38 insertions(+)
create mode 100644 arch/mips/mm/maccess.c

diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index d273a3857809..c5cab0b8f902 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -355,6 +355,18 @@ do { \
(val) = __gu_tmp.t; \
}

+#define HAVE_GET_KERNEL_NOFAULT
+
+#define __get_kernel_nofault(dst, src, type, err_label) \
+do { \
+ int __gu_err; \
+ \
+ __get_kernel_common(*((type *)(dst)), sizeof(type), \
+ (__force type *)(src)); \
+ if (unlikely(__gu_err)) \
+ goto err_label; \
+} while (0)
+
#ifndef CONFIG_EVA
#define __put_kernel_common(ptr, size) __put_user_common(ptr, size)
#else
@@ -483,6 +495,18 @@ do { \

extern void __put_user_unknown(void);

+#define __put_kernel_nofault(dst, src, type, err_label) \
+do { \
+ type __pu_val; \
+ int __pu_err = 0; \
+ \
+ __pu_val = *(__force type *)(src); \
+ __put_kernel_common(((type *)(dst)), sizeof(type)); \
+ if (unlikely(__pu_err)) \
+ goto err_label; \
+} while (0)
+
+
/*
* We're generating jump to subroutines which will be outside the range of
* jump instructions
diff --git a/arch/mips/mm/Makefile b/arch/mips/mm/Makefile
index 865926a37775..76e3ee8882fa 100644
--- a/arch/mips/mm/Makefile
+++ b/arch/mips/mm/Makefile
@@ -22,6 +22,10 @@ else
obj-y += uasm-mips.o
endif

+ifndef CONFIG_EVA
+obj-y += maccess.o
+endif
+
obj-$(CONFIG_32BIT) += ioremap.o pgtable-32.o
obj-$(CONFIG_64BIT) += ioremap64.o pgtable-64.o
obj-$(CONFIG_HIGHMEM) += highmem.o
diff --git a/arch/mips/mm/maccess.c b/arch/mips/mm/maccess.c
new file mode 100644
index 000000000000..58173842c6be
--- /dev/null
+++ b/arch/mips/mm/maccess.c
@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+
+bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+{
+ /* highest bit set means kernel space */
+ return (unsigned long)unsafe_src >> (BITS_PER_LONG - 1);
+}
--
2.29.2