Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH v3 2/7] arm: fixmap: implement __set_fixmap() | Date | Tue, 12 Aug 2014 11:24:24 -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> --- arch/arm/include/asm/fixmap.h | 2 ++ arch/arm/mm/mmu.c | 19 +++++++++++++++++++ 2 files changed, 21 insertions(+)
diff --git a/arch/arm/include/asm/fixmap.h b/arch/arm/include/asm/fixmap.h index a7add6f9315d..48935cc5004f 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..48ba2b1d7d8e 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 +393,24 @@ 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(FIXADDR_START), 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); + 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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