diff options
| -rw-r--r-- | arch/arm64/mm/mmu.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 14a62c773201..9758f7e3f4b6 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -55,6 +55,8 @@ EXPORT_SYMBOL(kimage_voffset); u32 __boot_cpu_mode[] = { BOOT_CPU_MODE_EL2, BOOT_CPU_MODE_EL1 }; +static bool rodata_is_rw __ro_after_init = true; + /* * The booting CPU updates the failed status @__early_cpu_boot_status, * with MMU turned off. @@ -71,10 +73,21 @@ EXPORT_SYMBOL(empty_zero_page); static DEFINE_SPINLOCK(swapper_pgdir_lock); static DEFINE_MUTEX(fixmap_lock); -void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) +void noinstr set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) { pgd_t *fixmap_pgdp; + /* + * Don't bother with the fixmap if swapper_pg_dir is still mapped + * writable in the kernel mapping. + */ + if (rodata_is_rw) { + WRITE_ONCE(*pgdp, pgd); + dsb(ishst); + isb(); + return; + } + spin_lock(&swapper_pgdir_lock); fixmap_pgdp = pgd_set_fixmap(__pa_symbol(pgdp)); WRITE_ONCE(*fixmap_pgdp, pgd); @@ -628,6 +641,7 @@ void mark_rodata_ro(void) * to cover NOTES and EXCEPTION_TABLE. */ section_size = (unsigned long)__init_begin - (unsigned long)__start_rodata; + WRITE_ONCE(rodata_is_rw, false); update_mapping_prot(__pa_symbol(__start_rodata), (unsigned long)__start_rodata, section_size, PAGE_KERNEL_RO); |