diff options
Diffstat (limited to 'arch/arm/mm')
| -rw-r--r-- | arch/arm/mm/Kconfig | 34 | ||||
| -rw-r--r-- | arch/arm/mm/mmu.c | 14 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7-2level.S | 2 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7-3level.S | 2 | ||||
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 11 |
5 files changed, 55 insertions, 8 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 35955b54944..2950082a531 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -411,24 +411,28 @@ config CPU_32v3 select CPU_USE_DOMAINS if MMU select NEEDS_SYSCALL_FOR_CMPXCHG if SMP select TLS_REG_EMUL if SMP || !MMU + select NEED_KUSER_HELPERS config CPU_32v4 bool select CPU_USE_DOMAINS if MMU select NEEDS_SYSCALL_FOR_CMPXCHG if SMP select TLS_REG_EMUL if SMP || !MMU + select NEED_KUSER_HELPERS config CPU_32v4T bool select CPU_USE_DOMAINS if MMU select NEEDS_SYSCALL_FOR_CMPXCHG if SMP select TLS_REG_EMUL if SMP || !MMU + select NEED_KUSER_HELPERS config CPU_32v5 bool select CPU_USE_DOMAINS if MMU select NEEDS_SYSCALL_FOR_CMPXCHG if SMP select TLS_REG_EMUL if SMP || !MMU + select NEED_KUSER_HELPERS config CPU_32v6 bool @@ -756,6 +760,7 @@ config CPU_BPREDICT_DISABLE config TLS_REG_EMUL bool + select NEED_KUSER_HELPERS help An SMP system using a pre-ARMv6 processor (there are apparently a few prototypes like that in existence) and therefore access to @@ -763,11 +768,40 @@ config TLS_REG_EMUL config NEEDS_SYSCALL_FOR_CMPXCHG bool + select NEED_KUSER_HELPERS help SMP on a pre-ARMv6 processor? Well OK then. Forget about fast user space cmpxchg support. It is just not possible. +config NEED_KUSER_HELPERS + bool + +config KUSER_HELPERS + bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS + default y + help + Warning: disabling this option may break user programs. + + Provide kuser helpers in the vector page. The kernel provides + helper code to userspace in read only form at a fixed location + in the high vector page to allow userspace to be independent of + the CPU type fitted to the system. This permits binaries to be + run on ARMv4 through to ARMv7 without modification. + + However, the fixed address nature of these helpers can be used + by ROP (return orientated programming) authors when creating + exploits. + + If all of the binaries and libraries which run on your platform + are built specifically for your platform, and make no use of + these helpers, then you can turn this option off. However, + when such an binary or library is run, it will receive a SIGILL + signal, which will terminate the program. + + Say N here only if you are absolutely certain that you do not + need these helpers; otherwise, the safe option is to say Y. + config DMA_CACHE_RWFO bool "Enable read/write for ownership DMA cache maintenance" depends on CPU_V6K && SMP diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 394342d0482..b832135ec43 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -1220,7 +1220,7 @@ static void __init devicemaps_init(struct machine_desc *mdesc) /* * Allocate the vector page early. */ - vectors = early_alloc(PAGE_SIZE); + vectors = early_alloc(PAGE_SIZE * 2); early_trap_init(vectors); @@ -1265,15 +1265,27 @@ static void __init devicemaps_init(struct machine_desc *mdesc) map.pfn = __phys_to_pfn(virt_to_phys(vectors)); map.virtual = 0xffff0000; map.length = PAGE_SIZE; +#ifdef CONFIG_KUSER_HELPERS map.type = MT_HIGH_VECTORS; +#else + map.type = MT_LOW_VECTORS; +#endif create_mapping(&map, false); if (!vectors_high()) { map.virtual = 0; + map.length = PAGE_SIZE * 2; map.type = MT_LOW_VECTORS; create_mapping(&map, false); } + /* Now create a kernel read-only mapping */ + map.pfn += 1; + map.virtual = 0xffff0000 + PAGE_SIZE; + map.length = PAGE_SIZE; + map.type = MT_LOW_VECTORS; + create_mapping(&map, false); + /* * Ask the machine support to map in the statically mapped devices. */ diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S index 9704097c450..b3997c70af3 100644 --- a/arch/arm/mm/proc-v7-2level.S +++ b/arch/arm/mm/proc-v7-2level.S @@ -110,7 +110,7 @@ ENTRY(cpu_v7_set_pte_ext) ARM( str r3, [r0, #2048]! ) THUMB( add r0, r0, #2048 ) THUMB( str r3, [r0] ) - ALT_SMP(mov pc,lr) + ALT_SMP(W(nop)) ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte #endif mov pc, lr diff --git a/arch/arm/mm/proc-v7-3level.S b/arch/arm/mm/proc-v7-3level.S index 363027e811d..6ba4bd9118f 100644 --- a/arch/arm/mm/proc-v7-3level.S +++ b/arch/arm/mm/proc-v7-3level.S @@ -73,7 +73,7 @@ ENTRY(cpu_v7_set_pte_ext) tst r3, #1 << (55 - 32) @ L_PTE_DIRTY orreq r2, #L_PTE_RDONLY 1: strd r2, r3, [r0] - ALT_SMP(mov pc, lr) + ALT_SMP(W(nop)) ALT_UP (mcr p15, 0, r0, c7, c10, 1) @ flush_pte #endif mov pc, lr diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index e35fec34453..5fbccee5f64 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -75,13 +75,14 @@ ENTRY(cpu_v7_do_idle) ENDPROC(cpu_v7_do_idle) ENTRY(cpu_v7_dcache_clean_area) - ALT_SMP(mov pc, lr) @ MP extensions imply L1 PTW - ALT_UP(W(nop)) - dcache_line_size r2, r3 -1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry + ALT_SMP(W(nop)) @ MP extensions imply L1 PTW + ALT_UP_B(1f) + mov pc, lr +1: dcache_line_size r2, r3 +2: mcr p15, 0, r0, c7, c10, 1 @ clean D entry add r0, r0, r2 subs r1, r1, r2 - bhi 1b + bhi 2b dsb mov pc, lr ENDPROC(cpu_v7_dcache_clean_area) |