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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/parisc/include/asm/uaccess.h
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/parisc/include/asm/uaccess.h')
-rw-r--r--arch/parisc/include/asm/uaccess.h227
1 files changed, 227 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
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+++ b/arch/parisc/include/asm/uaccess.h
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+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PARISC_UACCESS_H
+#define __PARISC_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <asm/page.h>
+#include <asm/cache.h>
+
+#include <linux/bug.h>
+#include <linux/string.h>
+
+#define KERNEL_DS ((mm_segment_t){0})
+#define USER_DS ((mm_segment_t){1})
+
+#define segment_eq(a, b) ((a).seg == (b).seg)
+
+#define get_ds() (KERNEL_DS)
+#define get_fs() (current_thread_info()->addr_limit)
+#define set_fs(x) (current_thread_info()->addr_limit = (x))
+
+/*
+ * Note that since kernel addresses are in a separate address space on
+ * parisc, we don't need to do anything for access_ok().
+ * We just let the page fault handler do the right thing. This also means
+ * that put_user is the same as __put_user, etc.
+ */
+
+#define access_ok(type, uaddr, size) \
+ ( (uaddr) == (uaddr) )
+
+#define put_user __put_user
+#define get_user __get_user
+
+#if !defined(CONFIG_64BIT)
+#define LDD_USER(val, ptr) __get_user_asm64(val, ptr)
+#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
+#else
+#define LDD_USER(val, ptr) __get_user_asm(val, "ldd", ptr)
+#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
+#endif
+
+/*
+ * The exception table contains two values: the first is the relative offset to
+ * the address of the instruction that is allowed to fault, and the second is
+ * the relative offset to the address of the fixup routine. Since relative
+ * addresses are used, 32bit values are sufficient even on 64bit kernel.
+ */
+
+#define ARCH_HAS_RELATIVE_EXTABLE
+struct exception_table_entry {
+ int insn; /* relative address of insn that is allowed to fault. */
+ int fixup; /* relative address of fixup routine */
+};
+
+#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
+ ".section __ex_table,\"aw\"\n" \
+ ".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
+ ".previous\n"
+
+/*
+ * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
+ * (with lowest bit set) for which the fault handler in fixup_exception() will
+ * load -EFAULT into %r8 for a read or write fault, and zeroes the target
+ * register in case of a read fault in get_user().
+ */
+#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\
+ ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1)
+
+/*
+ * load_sr2() preloads the space register %%sr2 - based on the value of
+ * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
+ * is 0), or with the current value of %%sr3 to access user space (USER_DS)
+ * memory. The following __get_user_asm() and __put_user_asm() functions have
+ * %%sr2 hard-coded to access the requested memory.
+ */
+#define load_sr2() \
+ __asm__(" or,= %0,%%r0,%%r0\n\t" \
+ " mfsp %%sr3,%0\n\t" \
+ " mtsp %0,%%sr2\n\t" \
+ : : "r"(get_fs()) : )
+
+#define __get_user_internal(val, ptr) \
+({ \
+ register long __gu_err __asm__ ("r8") = 0; \
+ \
+ switch (sizeof(*(ptr))) { \
+ case 1: __get_user_asm(val, "ldb", ptr); break; \
+ case 2: __get_user_asm(val, "ldh", ptr); break; \
+ case 4: __get_user_asm(val, "ldw", ptr); break; \
+ case 8: LDD_USER(val, ptr); break; \
+ default: BUILD_BUG(); \
+ } \
+ \
+ __gu_err; \
+})
+
+#define __get_user(val, ptr) \
+({ \
+ load_sr2(); \
+ __get_user_internal(val, ptr); \
+})
+
+#define __get_user_asm(val, ldx, ptr) \
+{ \
+ register long __gu_val; \
+ \
+ __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ : "=r"(__gu_val), "=r"(__gu_err) \
+ : "r"(ptr), "1"(__gu_err)); \
+ \
+ (val) = (__force __typeof__(*(ptr))) __gu_val; \
+}
+
+#if !defined(CONFIG_64BIT)
+
+#define __get_user_asm64(val, ptr) \
+{ \
+ union { \
+ unsigned long long l; \
+ __typeof__(*(ptr)) t; \
+ } __gu_tmp; \
+ \
+ __asm__(" copy %%r0,%R0\n" \
+ "1: ldw 0(%%sr2,%2),%0\n" \
+ "2: ldw 4(%%sr2,%2),%R0\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
+ : "=&r"(__gu_tmp.l), "=r"(__gu_err) \
+ : "r"(ptr), "1"(__gu_err)); \
+ \
+ (val) = __gu_tmp.t; \
+}
+
+#endif /* !defined(CONFIG_64BIT) */
+
+
+#define __put_user_internal(x, ptr) \
+({ \
+ register long __pu_err __asm__ ("r8") = 0; \
+ __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x); \
+ \
+ switch (sizeof(*(ptr))) { \
+ case 1: __put_user_asm("stb", __x, ptr); break; \
+ case 2: __put_user_asm("sth", __x, ptr); break; \
+ case 4: __put_user_asm("stw", __x, ptr); break; \
+ case 8: STD_USER(__x, ptr); break; \
+ default: BUILD_BUG(); \
+ } \
+ \
+ __pu_err; \
+})
+
+#define __put_user(x, ptr) \
+({ \
+ load_sr2(); \
+ __put_user_internal(x, ptr); \
+})
+
+
+/*
+ * The "__put_user/kernel_asm()" macros tell gcc they read from memory
+ * instead of writing. This is because they do not write to any memory
+ * gcc knows about, so there are no aliasing issues. These macros must
+ * also be aware that fixups are executed in the context of the fault,
+ * and any registers used there must be listed as clobbers.
+ * r8 is already listed as err.
+ */
+
+#define __put_user_asm(stx, x, ptr) \
+ __asm__ __volatile__ ( \
+ "1: " stx " %2,0(%%sr2,%1)\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ : "=r"(__pu_err) \
+ : "r"(ptr), "r"(x), "0"(__pu_err))
+
+
+#if !defined(CONFIG_64BIT)
+
+#define __put_user_asm64(__val, ptr) do { \
+ __asm__ __volatile__ ( \
+ "1: stw %2,0(%%sr2,%1)\n" \
+ "2: stw %R2,4(%%sr2,%1)\n" \
+ "9:\n" \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \
+ ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \
+ : "=r"(__pu_err) \
+ : "r"(ptr), "r"(__val), "0"(__pu_err)); \
+} while (0)
+
+#endif /* !defined(CONFIG_64BIT) */
+
+
+/*
+ * Complex access routines -- external declarations
+ */
+
+extern long strncpy_from_user(char *, const char __user *, long);
+extern unsigned lclear_user(void __user *, unsigned long);
+extern long lstrnlen_user(const char __user *, long);
+/*
+ * Complex access routines -- macros
+ */
+#define user_addr_max() (~0UL)
+
+#define strnlen_user lstrnlen_user
+#define clear_user lclear_user
+#define __clear_user lclear_user
+
+unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src,
+ unsigned long len);
+unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src,
+ unsigned long len);
+unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src,
+ unsigned long len);
+#define INLINE_COPY_TO_USER
+#define INLINE_COPY_FROM_USER
+
+struct pt_regs;
+int fixup_exception(struct pt_regs *regs);
+
+#endif /* __PARISC_UACCESS_H */