Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH v5 3/8] arm: fixmap: implement __set_fixmap() | Date | Wed, 3 Sep 2014 14:57:04 -0700 |
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This is used from set_fixmap() and clear_fixmap() via asm-generic/fixmap.h. Also makes sure that the fixmap allocation fits into the expected range.
Based on patch by Rabin Vincent.
Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Rabin Vincent <rabin@rab.in> Acked-by: Nicolas Pitre <nico@linaro.org> --- arch/arm/include/asm/fixmap.h | 2 ++ arch/arm/mm/mmu.c | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+)
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index d984ca69ce19..714606f70425 100644 --- a/arch/arm/include/asm/fixmap.h +++ b/arch/arm/include/asm/fixmap.h @@ -14,6 +14,8 @@ enum fixed_addresses { __end_of_fixed_addresses }; +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); + #include <asm-generic/fixmap.h> #endif diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 7fa0966cd15f..fa3a667852cb 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -22,6 +22,7 @@ #include <asm/cputype.h> #include <asm/sections.h> #include <asm/cachetype.h> +#include <asm/fixmap.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/smp_plat.h> @@ -392,6 +393,30 @@ SET_MEMORY_FN(rw, pte_set_rw) SET_MEMORY_FN(x, pte_set_x) SET_MEMORY_FN(nx, pte_set_nx) +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long vaddr = __fix_to_virt(idx); + pte_t *pte = pte_offset_kernel(pmd_off_k(vaddr), vaddr); + + /* Make sure fixmap region does not exceed available allocation. */ + BUILD_BUG_ON(FIXADDR_START + (__end_of_fixed_addresses * PAGE_SIZE) > + FIXADDR_END); + BUG_ON(idx >= __end_of_fixed_addresses); + + if (pgprot_val(prot)) + set_pte_at(NULL, vaddr, pte, + pfn_pte(phys >> PAGE_SHIFT, prot)); + else + pte_clear(NULL, vaddr, pte); + + /* + * Given the potential a15 tlbi errata, we can only do tlb flushes + * with interrupts disabled. Callers must have taken care of this. + */ + WARN_ON_ONCE(!irqs_disabled()); + flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); +} + /* * Adjust the PMD section entries according to the CPU in use. */ -- 1.9.1
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