cregit-Linux how code gets into the kernel

Release 4.14 arch/sparc/include/asm/uaccess_64.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_UACCESS_H

#define _ASM_UACCESS_H

/*
 * User space memory access functions
 */

#include <linux/compiler.h>
#include <linux/string.h>
#include <asm/asi.h>
#include <asm/spitfire.h>
#include <asm/extable_64.h>

#include <asm/processor.h>

/*
 * Sparc64 is segmented, though more like the M68K than the I386.
 * We use the secondary ASI to address user memory, which references a
 * completely different VM map, thus there is zero chance of the user
 * doing something queer and tricking us into poking kernel memory.
 *
 * What is left here is basically what is needed for the other parts of
 * the kernel that expect to be able to manipulate, erum, "segments".
 * Or perhaps more properly, permissions.
 *
 * "For historical reasons, these macros are grossly misnamed." -Linus
 */


#define KERNEL_DS   ((mm_segment_t) { ASI_P })

#define USER_DS     ((mm_segment_t) { ASI_AIUS })	
/* har har har */


#define get_fs() ((mm_segment_t){(current_thread_info()->current_ds)})

#define get_ds() (KERNEL_DS)


#define segment_eq(a, b)  ((a).seg == (b).seg)


#define set_fs(val)								\
do {                                                                            \
        current_thread_info()->current_ds = (val).seg;                          \
        __asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg));        \
} while(0)

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 0 if the range is valid, nonzero otherwise.
 */

static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit) { if (__builtin_constant_p(size)) return addr > limit - size; addr += size; if (addr < size) return true; return addr > limit; }

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David Ahern51100.00%1100.00%
Total51100.00%1100.00%

#define __range_not_ok(addr, size, limit) \ ({ \ __chk_user_ptr(addr); \ __chk_range_not_ok((unsigned long __force)(addr), size, limit); \ })
static inline int __access_ok(const void __user * addr, unsigned long size) { return 1; }

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Sam Ravnborg20100.00%1100.00%
Total20100.00%1100.00%


static inline int access_ok(int type, const void __user * addr, unsigned long size) { return 1; }

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Sam Ravnborg23100.00%1100.00%
Total23100.00%1100.00%

void __retl_efault(void); /* Uh, these should become the main single-value transfer routines.. * They automatically use the right size if we just have the right * pointer type.. * * This gets kind of ugly. We want to return _two_ values in "get_user()" * and yet we don't want to do any pointers, because that is too much * of a performance impact. Thus we have a few rather ugly macros here, * and hide all the ugliness from the user. */ #define put_user(x, ptr) ({ \ unsigned long __pu_addr = (unsigned long)(ptr); \ __chk_user_ptr(ptr); \ __put_user_nocheck((__typeof__(*(ptr)))(x), __pu_addr, sizeof(*(ptr)));\ }) #define get_user(x, ptr) ({ \ unsigned long __gu_addr = (unsigned long)(ptr); \ __chk_user_ptr(ptr); \ __get_user_nocheck((x), __gu_addr, sizeof(*(ptr)), __typeof__(*(ptr)));\ }) #define __put_user(x, ptr) put_user(x, ptr) #define __get_user(x, ptr) get_user(x, ptr) struct __large_struct { unsigned long buf[100]; }; #define __m(x) ((struct __large_struct *)(x)) #define __put_user_nocheck(data, addr, size) ({ \ register int __pu_ret; \ switch (size) { \ case 1: __put_user_asm(data, b, addr, __pu_ret); break; \ case 2: __put_user_asm(data, h, addr, __pu_ret); break; \ case 4: __put_user_asm(data, w, addr, __pu_ret); break; \ case 8: __put_user_asm(data, x, addr, __pu_ret); break; \ default: __pu_ret = __put_user_bad(); break; \ } \ __pu_ret; \ }) #define __put_user_asm(x, size, addr, ret) \ __asm__ __volatile__( \ "/* Put user asm, inline. */\n" \ "1:\t" "st"#size "a %1, [%2] %%asi\n\t" \ "clr %0\n" \ "2:\n\n\t" \ ".section .fixup,#alloc,#execinstr\n\t" \ ".align 4\n" \ "3:\n\t" \ "sethi %%hi(2b), %0\n\t" \ "jmpl %0 + %%lo(2b), %%g0\n\t" \ " mov %3, %0\n\n\t" \ ".previous\n\t" \ ".section __ex_table,\"a\"\n\t" \ ".align 4\n\t" \ ".word 1b, 3b\n\t" \ ".previous\n\n\t" \ : "=r" (ret) : "r" (x), "r" (__m(addr)), \ "i" (-EFAULT)) int __put_user_bad(void); #define __get_user_nocheck(data, addr, size, type) ({ \ register int __gu_ret; \ register unsigned long __gu_val; \ switch (size) { \ case 1: __get_user_asm(__gu_val, ub, addr, __gu_ret); break; \ case 2: __get_user_asm(__gu_val, uh, addr, __gu_ret); break; \ case 4: __get_user_asm(__gu_val, uw, addr, __gu_ret); break; \ case 8: __get_user_asm(__gu_val, x, addr, __gu_ret); break; \ default: \ __gu_val = 0; \ __gu_ret = __get_user_bad(); \ break; \ } \ data = (__force type) __gu_val; \ __gu_ret; \ }) #define __get_user_asm(x, size, addr, ret) \ __asm__ __volatile__( \ "/* Get user asm, inline. */\n" \ "1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \ "clr %0\n" \ "2:\n\n\t" \ ".section .fixup,#alloc,#execinstr\n\t" \ ".align 4\n" \ "3:\n\t" \ "sethi %%hi(2b), %0\n\t" \ "clr %1\n\t" \ "jmpl %0 + %%lo(2b), %%g0\n\t" \ " mov %3, %0\n\n\t" \ ".previous\n\t" \ ".section __ex_table,\"a\"\n\t" \ ".align 4\n\t" \ ".word 1b, 3b\n\n\t" \ ".previous\n\t" \ : "=r" (ret), "=r" (x) : "r" (__m(addr)), \ "i" (-EFAULT)) int __get_user_bad(void); unsigned long __must_check raw_copy_from_user(void *to, const void __user *from, unsigned long size); unsigned long __must_check raw_copy_to_user(void __user *to, const void *from, unsigned long size); #define INLINE_COPY_FROM_USER #define INLINE_COPY_TO_USER unsigned long __must_check raw_copy_in_user(void __user *to, const void __user *from, unsigned long size); unsigned long __must_check __clear_user(void __user *, unsigned long); #define clear_user __clear_user __must_check long strnlen_user(const char __user *str, long n); struct pt_regs; unsigned long compute_effective_address(struct pt_regs *, unsigned int insn, unsigned int rd); #endif /* _ASM_UACCESS_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Sam Ravnborg30673.38%19.09%
David Ahern6415.35%19.09%
David S. Miller276.47%218.18%
Michael S. Tsirkin92.16%218.18%
Al Viro92.16%327.27%
Greg Kroah-Hartman10.24%19.09%
Alexey Dobriyan10.24%19.09%
Total417100.00%11100.00%
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