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-rw-r--r--arch/arm/mm/Kconfig37
-rw-r--r--arch/arm/mm/context.c3
-rw-r--r--arch/arm/mm/mmu.c57
-rw-r--r--arch/arm/mm/proc-v7-2level.S2
-rw-r--r--arch/arm/mm/proc-v7-3level.S2
-rw-r--r--arch/arm/mm/proc-v7.S11
6 files changed, 98 insertions, 14 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 6cacdc8dd654..cd2c88e7a8f7 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -421,24 +421,28 @@ 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
@@ -776,6 +780,7 @@ 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
@@ -783,11 +788,43 @@ 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.
+
+ See Documentation/arm/kernel_user_helpers.txt for details.
+
+ 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 to hinder
+ such exploits. However, in that case, if a binary or library
+ relying on those helpers 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/context.c b/arch/arm/mm/context.c
index b55b1015724b..4a0544492f10 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -245,7 +245,8 @@ void check_and_switch_context(struct mm_struct *mm, struct task_struct *tsk)
if (cpumask_test_and_clear_cpu(cpu, &tlb_flush_pending)) {
local_flush_bp_all();
local_flush_tlb_all();
- dummy_flush_tlb_a15_erratum();
+ if (erratum_a15_798181())
+ dummy_flush_tlb_a15_erratum();
}
atomic64_set(&per_cpu(active_asids, cpu), asid);
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 4f56617a2392..53cdbd39ec8e 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -989,6 +989,7 @@ phys_addr_t arm_lowmem_limit __initdata = 0;
void __init sanity_check_meminfo(void)
{
+ phys_addr_t memblock_limit = 0;
int i, j, highmem = 0;
phys_addr_t vmalloc_limit = __pa(vmalloc_min - 1) + 1;
@@ -1052,9 +1053,32 @@ void __init sanity_check_meminfo(void)
bank->size = size_limit;
}
#endif
- if (!bank->highmem && bank->start + bank->size > arm_lowmem_limit)
- arm_lowmem_limit = bank->start + bank->size;
+ if (!bank->highmem) {
+ phys_addr_t bank_end = bank->start + bank->size;
+ if (bank_end > arm_lowmem_limit)
+ arm_lowmem_limit = bank_end;
+
+ /*
+ * Find the first non-section-aligned page, and point
+ * memblock_limit at it. This relies on rounding the
+ * limit down to be section-aligned, which happens at
+ * the end of this function.
+ *
+ * With this algorithm, the start or end of almost any
+ * bank can be non-section-aligned. The only exception
+ * is that the start of the bank 0 must be section-
+ * aligned, since otherwise memory would need to be
+ * allocated when mapping the start of bank 0, which
+ * occurs before any free memory is mapped.
+ */
+ if (!memblock_limit) {
+ if (!IS_ALIGNED(bank->start, SECTION_SIZE))
+ memblock_limit = bank->start;
+ else if (!IS_ALIGNED(bank_end, SECTION_SIZE))
+ memblock_limit = bank_end;
+ }
+ }
j++;
}
#ifdef CONFIG_HIGHMEM
@@ -1079,7 +1103,18 @@ void __init sanity_check_meminfo(void)
#endif
meminfo.nr_banks = j;
high_memory = __va(arm_lowmem_limit - 1) + 1;
- memblock_set_current_limit(arm_lowmem_limit);
+
+ /*
+ * Round the memblock limit down to a section size. This
+ * helps to ensure that we will allocate memory from the
+ * last full section, which should be mapped.
+ */
+ if (memblock_limit)
+ memblock_limit = round_down(memblock_limit, SECTION_SIZE);
+ if (!memblock_limit)
+ memblock_limit = arm_lowmem_limit;
+
+ memblock_set_current_limit(memblock_limit);
}
static inline void prepare_page_table(void)
@@ -1160,7 +1195,7 @@ 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);
@@ -1205,15 +1240,27 @@ 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);
if (!vectors_high()) {
map.virtual = 0;
+ map.length = PAGE_SIZE * 2;
map.type = MT_LOW_VECTORS;
create_mapping(&map);
}
+ /* 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);
+
/*
* Ask the machine support to map in the statically mapped devices.
*/
@@ -1276,8 +1323,6 @@ void __init paging_init(struct machine_desc *mdesc)
{
void *zero_page;
- memblock_set_current_limit(arm_lowmem_limit);
-
build_mem_type_table();
prepare_page_table();
map_lowmem();
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index f64afb9f1bd5..bdd3be4be77a 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 c36ac69488c8..01a719e18bb0 100644
--- a/arch/arm/mm/proc-v7-3level.S
+++ b/arch/arm/mm/proc-v7-3level.S
@@ -81,7 +81,7 @@ 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 5c6d5a3050ea..73398bcf9bd8 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)
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 17:29:38 +0000