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riscv: drop the use of XIP_OFFSET in create_kernel_page_table()

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XIP_OFFSET is the hard-coded offset of writable data section within the
kernel.

By hard-coding this value, the read-only section of the kernel (which is
placed before the writable data section) is restricted in size.

As a preparation to remove this hard-coded value entirely, stop using
XIP_OFFSET in create_kernel_page_table(). Instead use _sdata and _start to
do the same thing.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/4ea3f222a7eb9f91c04b155ff2e4d3ef19158acc.1717789719.git.namcao@linutronix.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Nam Cao 2024-06-07 22:22:12 +02:00 committed by Palmer Dabbelt
parent 75fdf791df
commit a7cfb99943
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1 changed files with 4 additions and 3 deletions
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7
arch/riscv/mm/init.c
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@ -917,7 +917,7 @@ static void __init relocate_kernel(void)
static void __init create_kernel_page_table(pgd_t *pgdir,
__always_unused bool early)
{
uintptr_t va, end_va;
uintptr_t va, start_va, end_va;
/* Map the flash resident part */
end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
@ -927,10 +927,11 @@ static void __init create_kernel_page_table(pgd_t *pgdir,
PMD_SIZE, PAGE_KERNEL_EXEC);
/* Map the data in RAM */
start_va = kernel_map.virt_addr + (uintptr_t)&_sdata - (uintptr_t)&_start;
end_va = kernel_map.virt_addr + kernel_map.size;
for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += PMD_SIZE)
for (va = start_va; va < end_va; va += PMD_SIZE)
create_pgd_mapping(pgdir, va,
kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
kernel_map.phys_addr + (va - start_va),
PMD_SIZE, PAGE_KERNEL);
}
#else