RISC-V: use memcpy for kexec_file mode
The pointer to buffer loading kernel binaries is in kernel space for
kexec_fil mode, When copy_from_user copies data from pointer to a block
of memory, it checkes that the pointer is in the user space range, on
RISCV-V that is:
static inline bool __access_ok(unsigned long addr, unsigned long size)
{
return size <= TASK_SIZE && addr <= TASK_SIZE - size;
}
and TASK_SIZE is 0x4000000000 for 64-bits, which now causes
copy_from_user to reject the access of the field 'buf' of struct
kexec_segment that is in range [CONFIG_PAGE_OFFSET - VMALLOC_SIZE,
CONFIG_PAGE_OFFSET), is invalid user space pointer.
This patch fixes this issue by skipping access_ok(), use mempcy() instead.
Signed-off-by: Liao Chang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>