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RISC-V: Copy kernel memory mappings to userspace addrenv

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Copy the kernel mappings to the new (user) address environment. The
copyuing is done exactly once. This relies on the fact that the kernel
L1/L2 mappings will never change, as all of the kernel memory is mapped
upon boot.
This commit is contained in:
Ville Juven 2022-01-17 11:31:19 +02:00 committed by Xiang Xiao
parent 57127b9429
commit 1322f82802
1 changed files with 48 additions and 0 deletions
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48
arch/risc-v/src/common/riscv_addrenv.c
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@ -88,6 +88,12 @@
#define ADDRENV_VBASE (CONFIG_ARCH_DATA_VBASE)
/****************************************************************************
* Public Data
****************************************************************************/
extern uintptr_t g_kernel_mappings;
/****************************************************************************
* Private Functions
****************************************************************************/
@ -187,6 +193,38 @@ static int create_spgtables(group_addrenv_t *addrenv)
return i;
}
/****************************************************************************
* Name: copy_kernel_mappings
*
* Description:
* Copy kernel mappings to address environment. Expects that the user page
* table does not contain any mappings yet (as they will be wiped).
*
* Input Parameters:
* addrenv - Describes the address environment. The page tables must exist
* at this point.
*
* Returned value:
* OK on success, ERROR on failure
*
****************************************************************************/
static int copy_kernel_mappings(group_addrenv_t *addrenv)
{
uintptr_t user_mappings = addrenv->spgtables[0];
/* Copy the L1 references */
if (user_mappings == 0)
{
return -EINVAL;
}
memcpy((void *)user_mappings, (void *)g_kernel_mappings, RV_MMU_PAGE_SIZE);
return OK;
}
/****************************************************************************
* Name: create_region
*
@ -343,6 +381,16 @@ int up_addrenv_create(size_t textsize, size_t datasize, size_t heapsize,
goto errout;
}
/* Map the kernel memory for the user */
ret = copy_kernel_mappings(addrenv);
if (ret < 0)
{
serr("ERROR: Failed to copy kernel mappings to new environment");
goto errout;
}
/* Calculate the base addresses for convenience */
resvbase = ADDRENV_VBASE;