copy.c File Reference

#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include <sys/kassert.h>
#include <machine/pmap.h>

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Functions
int	copy_unsafe (void *to_addr, void *from_addr, uintptr_t len)
int	copystr_unsafe (void *to_addr, void *from_addr, uintptr_t len)
int	Copy_In (uintptr_t fromuser, void *tokernel, uintptr_t len)
int	Copy_Out (void *fromkernel, uintptr_t touser, uintptr_t len)
int	Copy_StrIn (uintptr_t fromuser, void *tokernel, uintptr_t len)
int	Copy_StrOut (void *fromkernel, uintptr_t touser, uintptr_t len)

Function Documentation

Copy_In()

int Copy_In	(	uintptr_t	fromuser,
		void *	tokernel,
		uintptr_t	len
	)

Copy_In –

Safely copy memory from userspace. Prevents userspace pointers from reading kernel memory.

Side effects: Kernel page fault may have occurred.

Parameters

[in]	fromuser	User address to copy from.
[in]	tokernel	Kernel address to copy to.
[in]	len	Length of the data to copy.

Return values

EFAULT

if the address is invalid or causes a fault.

Definition at line 34 of file copy.c.

{
    if (len == 0)
        return 0;
 
    // Kernel space
    if (fromuser >= MEM_USERSPACE_TOP) {
        kprintf("Copy_In: address exceeds userspace top\n");
        return EFAULT;
    }
 
    // Wrap around
    if (len > (MEM_USERSPACE_TOP - fromuser)) {
        kprintf("Copy_In: length exceeds userspace top\n");
        return EFAULT;
    }
 
    return copy_unsafe(tokernel, (void *)fromuser, len);
}

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Copy_Out()

int Copy_Out	(	void *	fromkernel,
		uintptr_t	touser,
		uintptr_t	len
	)

Copy_Out –

Safely copy memory to userspace. Prevents userspace pointers from writing kernel memory.

Side effects: Kernel page fault may have occurred.

Parameters

[in]	fromkernel	Kernel address to copy from.
[in]	touser	User address to copy to.
[in]	len	Length of the data to copy.

Return values

EFAULT

if the address is invalid or causes a fault.

Definition at line 70 of file copy.c.

{
    if (len == 0)
        return 0;
 
    // Kernel space
    if (touser >= MEM_USERSPACE_TOP) {
        kprintf("Copy_Out: address exceeds userspace top\n");
        return EFAULT;
    }
 
    // Wrap around
    if (len > (MEM_USERSPACE_TOP - touser)) {
        kprintf("Copy_Out: length exceeds userspace top\n");
        return EFAULT;
    }
 
    return copy_unsafe((void *)touser, fromkernel, len);
}

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Copy_StrIn()

int Copy_StrIn	(	uintptr_t	fromuser,
		void *	tokernel,
		uintptr_t	len
	)

Copy_StrIn –

Safely copy a string from userspace. Prevents userspace pointers from reading kernel memory.

Side effects: Kernel page fault may have occurred.

Parameters

[in]	fromuser	User address to copy from.
[in]	tokernel	Kernel address to copy to.
[in]	len	Maximum string length.

Return values

EFAULT

if the address is invalid or causes a fault.

Definition at line 106 of file copy.c.

{
    if (len == 0)
        return 0;
 
    // Kernel space
    if (fromuser >= MEM_USERSPACE_TOP) {
        kprintf("Copy_StrIn: address exceeds userspace top\n");
        return EFAULT;
    }
 
    // Wrap around
    if (len > (MEM_USERSPACE_TOP - fromuser)) {
        kprintf("Copy_StrIn: length exceeds userspace top\n");
        return EFAULT;
    }
 
    return copystr_unsafe(tokernel, (void *)fromuser, len);
}

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Copy_StrOut()

int Copy_StrOut	(	void *	fromkernel,
		uintptr_t	touser,
		uintptr_t	len
	)

Copy_StrOut –

Safely copy a string to userspace. Prevents userspace pointers from writing kernel memory.

Side effects: Kernel page fault may have occurred.

Parameters

[in]	fromkernel	Kernel address to copy from.
[in]	touser	User address to copy to.
[in]	len	Maximum string length.

Return values

EFAULT

if the address is invalid or causes a fault.

Definition at line 142 of file copy.c.

{
    if (len == 0)
        return 0;
 
    // Kernel space
    if (touser >= MEM_USERSPACE_TOP) {
        kprintf("Copy_StrOut: address exceeds userspace top\n");
        return EFAULT;
    }
 
    // Wrap around
    if (len > (MEM_USERSPACE_TOP - touser)) {
        kprintf("Copy_StrOut: length exceeds userspace top\n");
        return EFAULT;
    }
 
    return copystr_unsafe((void *)touser, fromkernel, len);
}

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copy_unsafe()

int copy_unsafe	(	void *	to_addr,
		void *	from_addr,
		uintptr_t	len
	)

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copystr_unsafe()

int copystr_unsafe	(	void *	to_addr,
		void *	from_addr,
		uintptr_t	len
	)

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