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-rw-r--r--arch/arm/mm/Kconfig36
-rw-r--r--arch/arm/mm/cache-tauros2.c32
-rw-r--r--arch/arm/mm/dma-mapping.c248
-rw-r--r--arch/arm/mm/idmap.c2
-rw-r--r--arch/arm/mm/init.c24
-rw-r--r--arch/arm/mm/mmu.c8
-rw-r--r--arch/arm/mm/pageattr.c3
-rw-r--r--arch/arm/mm/proc-v7.S2
8 files changed, 259 insertions, 96 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 549f6d3aec5b..55347662e5ed 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1037,24 +1037,26 @@ config ARCH_SUPPORTS_BIG_ENDIAN
This option specifies the architecture can support big endian
operation.
-config ARM_KERNMEM_PERMS
- bool "Restrict kernel memory permissions"
- depends on MMU
- help
- If this is set, kernel memory other than kernel text (and rodata)
- will be made non-executable. The tradeoff is that each region is
- padded to section-size (1MiB) boundaries (because their permissions
- are different and splitting the 1M pages into 4K ones causes TLB
- performance problems), wasting memory.
-
config DEBUG_RODATA
bool "Make kernel text and rodata read-only"
- depends on ARM_KERNMEM_PERMS
+ depends on MMU && !XIP_KERNEL
+ default y if CPU_V7
+ help
+ If this is set, kernel text and rodata memory will be made
+ read-only, and non-text kernel memory will be made non-executable.
+ The tradeoff is that each region is padded to section-size (1MiB)
+ boundaries (because their permissions are different and splitting
+ the 1M pages into 4K ones causes TLB performance problems), which
+ can waste memory.
+
+config DEBUG_ALIGN_RODATA
+ bool "Make rodata strictly non-executable"
+ depends on DEBUG_RODATA
default y
help
- If this is set, kernel text and rodata will be made read-only. This
- is to help catch accidental or malicious attempts to change the
- kernel's executable code. Additionally splits rodata from kernel
- text so it can be made explicitly non-executable. This creates
- another section-size padded region, so it can waste more memory
- space while gaining the read-only protections.
+ If this is set, rodata will be made explicitly non-executable. This
+ provides protection on the rare chance that attackers might find and
+ use ROP gadgets that exist in the rodata section. This adds an
+ additional section-aligned split of rodata from kernel text so it
+ can be made explicitly non-executable. This padding may waste memory
+ space to gain the additional protection.
diff --git a/arch/arm/mm/cache-tauros2.c b/arch/arm/mm/cache-tauros2.c
index 1e373d268c04..88255bea65e4 100644
--- a/arch/arm/mm/cache-tauros2.c
+++ b/arch/arm/mm/cache-tauros2.c
@@ -22,6 +22,11 @@
#include <asm/cputype.h>
#include <asm/hardware/cache-tauros2.h>
+/* CP15 PJ4 Control configuration register */
+#define CCR_L2C_PREFETCH_DISABLE BIT(24)
+#define CCR_L2C_ECC_ENABLE BIT(23)
+#define CCR_L2C_WAY7_4_DISABLE BIT(21)
+#define CCR_L2C_BURST8_ENABLE BIT(20)
/*
* When Tauros2 is used on a CPU that supports the v7 hierarchical
@@ -182,18 +187,18 @@ static void enable_extra_feature(unsigned int features)
u = read_extra_features();
if (features & CACHE_TAUROS2_PREFETCH_ON)
- u &= ~0x01000000;
+ u &= ~CCR_L2C_PREFETCH_DISABLE;
else
- u |= 0x01000000;
+ u |= CCR_L2C_PREFETCH_DISABLE;
pr_info("Tauros2: %s L2 prefetch.\n",
(features & CACHE_TAUROS2_PREFETCH_ON)
? "Enabling" : "Disabling");
if (features & CACHE_TAUROS2_LINEFILL_BURST8)
- u |= 0x00100000;
+ u |= CCR_L2C_BURST8_ENABLE;
else
- u &= ~0x00100000;
- pr_info("Tauros2: %s line fill burt8.\n",
+ u &= ~CCR_L2C_BURST8_ENABLE;
+ pr_info("Tauros2: %s burst8 line fill.\n",
(features & CACHE_TAUROS2_LINEFILL_BURST8)
? "Enabling" : "Disabling");
@@ -287,16 +292,15 @@ void __init tauros2_init(unsigned int features)
node = of_find_matching_node(NULL, tauros2_ids);
if (!node) {
pr_info("Not found marvell,tauros2-cache, disable it\n");
- return;
+ } else {
+ ret = of_property_read_u32(node, "marvell,tauros2-cache-features", &f);
+ if (ret) {
+ pr_info("Not found marvell,tauros-cache-features property, "
+ "disable extra features\n");
+ features = 0;
+ } else
+ features = f;
}
-
- ret = of_property_read_u32(node, "marvell,tauros2-cache-features", &f);
- if (ret) {
- pr_info("Not found marvell,tauros-cache-features property, "
- "disable extra features\n");
- features = 0;
- } else
- features = f;
#endif
tauros2_internal_init(features);
}
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 0eca3812527e..deac58d5f1f7 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -42,6 +42,55 @@
#include "dma.h"
#include "mm.h"
+struct arm_dma_alloc_args {
+ struct device *dev;
+ size_t size;
+ gfp_t gfp;
+ pgprot_t prot;
+ const void *caller;
+ bool want_vaddr;
+};
+
+struct arm_dma_free_args {
+ struct device *dev;
+ size_t size;
+ void *cpu_addr;
+ struct page *page;
+ bool want_vaddr;
+};
+
+struct arm_dma_allocator {
+ void *(*alloc)(struct arm_dma_alloc_args *args,
+ struct page **ret_page);
+ void (*free)(struct arm_dma_free_args *args);
+};
+
+struct arm_dma_buffer {
+ struct list_head list;
+ void *virt;
+ struct arm_dma_allocator *allocator;
+};
+
+static LIST_HEAD(arm_dma_bufs);
+static DEFINE_SPINLOCK(arm_dma_bufs_lock);
+
+static struct arm_dma_buffer *arm_dma_buffer_find(void *virt)
+{
+ struct arm_dma_buffer *buf, *found = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&arm_dma_bufs_lock, flags);
+ list_for_each_entry(buf, &arm_dma_bufs, list) {
+ if (buf->virt == virt) {
+ list_del(&buf->list);
+ found = buf;
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
+ return found;
+}
+
/*
* The DMA API is built upon the notion of "buffer ownership". A buffer
* is either exclusively owned by the CPU (and therefore may be accessed
@@ -592,7 +641,7 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c, wv) NULL
#define __alloc_from_pool(size, ret_page) NULL
#define __alloc_from_contiguous(dev, size, prot, ret, c, wv) NULL
-#define __free_from_pool(cpu_addr, size) 0
+#define __free_from_pool(cpu_addr, size) do { } while (0)
#define __free_from_contiguous(dev, page, cpu_addr, size, wv) do { } while (0)
#define __dma_free_remap(cpu_addr, size) do { } while (0)
@@ -610,7 +659,78 @@ static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp,
return page_address(page);
}
+static void *simple_allocator_alloc(struct arm_dma_alloc_args *args,
+ struct page **ret_page)
+{
+ return __alloc_simple_buffer(args->dev, args->size, args->gfp,
+ ret_page);
+}
+
+static void simple_allocator_free(struct arm_dma_free_args *args)
+{
+ __dma_free_buffer(args->page, args->size);
+}
+static struct arm_dma_allocator simple_allocator = {
+ .alloc = simple_allocator_alloc,
+ .free = simple_allocator_free,
+};
+
+static void *cma_allocator_alloc(struct arm_dma_alloc_args *args,
+ struct page **ret_page)
+{
+ return __alloc_from_contiguous(args->dev, args->size, args->prot,
+ ret_page, args->caller,
+ args->want_vaddr);
+}
+
+static void cma_allocator_free(struct arm_dma_free_args *args)
+{
+ __free_from_contiguous(args->dev, args->page, args->cpu_addr,
+ args->size, args->want_vaddr);
+}
+
+static struct arm_dma_allocator cma_allocator = {
+ .alloc = cma_allocator_alloc,
+ .free = cma_allocator_free,
+};
+
+static void *pool_allocator_alloc(struct arm_dma_alloc_args *args,
+ struct page **ret_page)
+{
+ return __alloc_from_pool(args->size, ret_page);
+}
+
+static void pool_allocator_free(struct arm_dma_free_args *args)
+{
+ __free_from_pool(args->cpu_addr, args->size);
+}
+
+static struct arm_dma_allocator pool_allocator = {
+ .alloc = pool_allocator_alloc,
+ .free = pool_allocator_free,
+};
+
+static void *remap_allocator_alloc(struct arm_dma_alloc_args *args,
+ struct page **ret_page)
+{
+ return __alloc_remap_buffer(args->dev, args->size, args->gfp,
+ args->prot, ret_page, args->caller,
+ args->want_vaddr);
+}
+
+static void remap_allocator_free(struct arm_dma_free_args *args)
+{
+ if (args->want_vaddr)
+ __dma_free_remap(args->cpu_addr, args->size);
+
+ __dma_free_buffer(args->page, args->size);
+}
+
+static struct arm_dma_allocator remap_allocator = {
+ .alloc = remap_allocator_alloc,
+ .free = remap_allocator_free,
+};
static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, pgprot_t prot, bool is_coherent,
@@ -619,7 +739,16 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
u64 mask = get_coherent_dma_mask(dev);
struct page *page = NULL;
void *addr;
- bool want_vaddr;
+ bool allowblock, cma;
+ struct arm_dma_buffer *buf;
+ struct arm_dma_alloc_args args = {
+ .dev = dev,
+ .size = PAGE_ALIGN(size),
+ .gfp = gfp,
+ .prot = prot,
+ .caller = caller,
+ .want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs),
+ };
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
@@ -633,6 +762,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
if (!mask)
return NULL;
+ buf = kzalloc(sizeof(*buf), gfp);
+ if (!buf)
+ return NULL;
+
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
@@ -644,28 +777,37 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
* platform; see CONFIG_HUGETLBFS.
*/
gfp &= ~(__GFP_COMP);
+ args.gfp = gfp;
*handle = DMA_ERROR_CODE;
- size = PAGE_ALIGN(size);
- want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);
-
- if (nommu())
- addr = __alloc_simple_buffer(dev, size, gfp, &page);
- else if (dev_get_cma_area(dev) && (gfp & __GFP_DIRECT_RECLAIM))
- addr = __alloc_from_contiguous(dev, size, prot, &page,
- caller, want_vaddr);
- else if (is_coherent)
- addr = __alloc_simple_buffer(dev, size, gfp, &page);
- else if (!gfpflags_allow_blocking(gfp))
- addr = __alloc_from_pool(size, &page);
+ allowblock = gfpflags_allow_blocking(gfp);
+ cma = allowblock ? dev_get_cma_area(dev) : false;
+
+ if (cma)
+ buf->allocator = &cma_allocator;
+ else if (nommu() || is_coherent)
+ buf->allocator = &simple_allocator;
+ else if (allowblock)
+ buf->allocator = &remap_allocator;
else
- addr = __alloc_remap_buffer(dev, size, gfp, prot, &page,
- caller, want_vaddr);
+ buf->allocator = &pool_allocator;
+
+ addr = buf->allocator->alloc(&args, &page);
+
+ if (page) {
+ unsigned long flags;
- if (page)
*handle = pfn_to_dma(dev, page_to_pfn(page));
+ buf->virt = args.want_vaddr ? addr : page;
+
+ spin_lock_irqsave(&arm_dma_bufs_lock, flags);
+ list_add(&buf->list, &arm_dma_bufs);
+ spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
+ } else {
+ kfree(buf);
+ }
- return want_vaddr ? addr : page;
+ return args.want_vaddr ? addr : page;
}
/*
@@ -741,25 +883,21 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
bool is_coherent)
{
struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
- bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs);
-
- size = PAGE_ALIGN(size);
-
- if (nommu()) {
- __dma_free_buffer(page, size);
- } else if (!is_coherent && __free_from_pool(cpu_addr, size)) {
+ struct arm_dma_buffer *buf;
+ struct arm_dma_free_args args = {
+ .dev = dev,
+ .size = PAGE_ALIGN(size),
+ .cpu_addr = cpu_addr,
+ .page = page,
+ .want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs),
+ };
+
+ buf = arm_dma_buffer_find(cpu_addr);
+ if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr))
return;
- } else if (!dev_get_cma_area(dev)) {
- if (want_vaddr && !is_coherent)
- __dma_free_remap(cpu_addr, size);
- __dma_free_buffer(page, size);
- } else {
- /*
- * Non-atomic allocations cannot be freed with IRQs disabled
- */
- WARN_ON(irqs_disabled());
- __free_from_contiguous(dev, page, cpu_addr, size, want_vaddr);
- }
+
+ buf->allocator->free(&args);
+ kfree(buf);
}
void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
@@ -1122,6 +1260,9 @@ static inline void __free_iova(struct dma_iommu_mapping *mapping,
spin_unlock_irqrestore(&mapping->lock, flags);
}
+/* We'll try 2M, 1M, 64K, and finally 4K; array must end with 0! */
+static const int iommu_order_array[] = { 9, 8, 4, 0 };
+
static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
gfp_t gfp, struct dma_attrs *attrs)
{
@@ -1129,6 +1270,7 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
int count = size >> PAGE_SHIFT;
int array_size = count * sizeof(struct page *);
int i = 0;
+ int order_idx = 0;
if (array_size <= PAGE_SIZE)
pages = kzalloc(array_size, GFP_KERNEL);
@@ -1154,6 +1296,10 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
return pages;
}
+ /* Go straight to 4K chunks if caller says it's OK. */
+ if (dma_get_attr(DMA_ATTR_ALLOC_SINGLE_PAGES, attrs))
+ order_idx = ARRAY_SIZE(iommu_order_array) - 1;
+
/*
* IOMMU can map any pages, so himem can also be used here
*/
@@ -1162,22 +1308,24 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
while (count) {
int j, order;
- for (order = __fls(count); order > 0; --order) {
- /*
- * We do not want OOM killer to be invoked as long
- * as we can fall back to single pages, so we force
- * __GFP_NORETRY for orders higher than zero.
- */
- pages[i] = alloc_pages(gfp | __GFP_NORETRY, order);
- if (pages[i])
- break;
+ order = iommu_order_array[order_idx];
+
+ /* Drop down when we get small */
+ if (__fls(count) < order) {
+ order_idx++;
+ continue;
}
- if (!pages[i]) {
- /*
- * Fall back to single page allocation.
- * Might invoke OOM killer as last resort.
- */
+ if (order) {
+ /* See if it's easy to allocate a high-order chunk */
+ pages[i] = alloc_pages(gfp | __GFP_NORETRY, order);
+
+ /* Go down a notch at first sign of pressure */
+ if (!pages[i]) {
+ order_idx++;
+ continue;
+ }
+ } else {
pages[i] = alloc_pages(gfp, 0);
if (!pages[i])
goto error;
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index d65909697165..bd274a05b8ff 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -15,7 +15,7 @@
* page tables.
*/
pgd_t *idmap_pgd;
-phys_addr_t (*arch_virt_to_idmap) (unsigned long x);
+unsigned long (*arch_virt_to_idmap)(unsigned long x);
#ifdef CONFIG_ARM_LPAE
static void idmap_add_pmd(pud_t *pud, unsigned long addr, unsigned long end,
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 49bd08178008..370581aeb871 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -572,8 +572,9 @@ void __init mem_init(void)
}
}
-#ifdef CONFIG_ARM_KERNMEM_PERMS
+#ifdef CONFIG_DEBUG_RODATA
struct section_perm {
+ const char *name;
unsigned long start;
unsigned long end;
pmdval_t mask;
@@ -581,9 +582,13 @@ struct section_perm {
pmdval_t clear;
};
+/* First section-aligned location at or after __start_rodata. */
+extern char __start_rodata_section_aligned[];
+
static struct section_perm nx_perms[] = {
/* Make pages tables, etc before _stext RW (set NX). */
{
+ .name = "pre-text NX",
.start = PAGE_OFFSET,
.end = (unsigned long)_stext,
.mask = ~PMD_SECT_XN,
@@ -591,26 +596,26 @@ static struct section_perm nx_perms[] = {
},
/* Make init RW (set NX). */
{
+ .name = "init NX",
.start = (unsigned long)__init_begin,
.end = (unsigned long)_sdata,
.mask = ~PMD_SECT_XN,
.prot = PMD_SECT_XN,
},
-#ifdef CONFIG_DEBUG_RODATA
/* Make rodata NX (set RO in ro_perms below). */
{
- .start = (unsigned long)__start_rodata,
+ .name = "rodata NX",
+ .start = (unsigned long)__start_rodata_section_aligned,
.end = (unsigned long)__init_begin,
.mask = ~PMD_SECT_XN,
.prot = PMD_SECT_XN,
},
-#endif
};
-#ifdef CONFIG_DEBUG_RODATA
static struct section_perm ro_perms[] = {
/* Make kernel code and rodata RX (set RO). */
{
+ .name = "text/rodata RO",
.start = (unsigned long)_stext,
.end = (unsigned long)__init_begin,
#ifdef CONFIG_ARM_LPAE
@@ -623,7 +628,6 @@ static struct section_perm ro_perms[] = {
#endif
},
};
-#endif
/*
* Updates section permissions only for the current mm (sections are
@@ -670,8 +674,8 @@ void set_section_perms(struct section_perm *perms, int n, bool set,
for (i = 0; i < n; i++) {
if (!IS_ALIGNED(perms[i].start, SECTION_SIZE) ||
!IS_ALIGNED(perms[i].end, SECTION_SIZE)) {
- pr_err("BUG: section %lx-%lx not aligned to %lx\n",
- perms[i].start, perms[i].end,
+ pr_err("BUG: %s section %lx-%lx not aligned to %lx\n",
+ perms[i].name, perms[i].start, perms[i].end,
SECTION_SIZE);
continue;
}
@@ -712,7 +716,6 @@ void fix_kernmem_perms(void)
stop_machine(__fix_kernmem_perms, NULL, NULL);
}
-#ifdef CONFIG_DEBUG_RODATA
int __mark_rodata_ro(void *unused)
{
update_sections_early(ro_perms, ARRAY_SIZE(ro_perms));
@@ -735,11 +738,10 @@ void set_kernel_text_ro(void)
set_section_perms(ro_perms, ARRAY_SIZE(ro_perms), true,
current->active_mm);
}
-#endif /* CONFIG_DEBUG_RODATA */
#else
static inline void fix_kernmem_perms(void) { }
-#endif /* CONFIG_ARM_KERNMEM_PERMS */
+#endif /* CONFIG_DEBUG_RODATA */
void free_tcmmem(void)
{
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 434d76f0b363..e4b681aafd6d 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -1253,7 +1253,7 @@ static inline void prepare_page_table(void)
#ifdef CONFIG_XIP_KERNEL
/* The XIP kernel is mapped in the module area -- skip over it */
- addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK;
+ addr = ((unsigned long)_exiprom + PMD_SIZE - 1) & PMD_MASK;
#endif
for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
pmd_clear(pmd_off_k(addr));
@@ -1335,7 +1335,7 @@ static void __init devicemaps_init(const struct machine_desc *mdesc)
#ifdef CONFIG_XIP_KERNEL
map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
map.virtual = MODULES_VADDR;
- map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
+ map.length = ((unsigned long)_exiprom - map.virtual + ~SECTION_MASK) & SECTION_MASK;
map.type = MT_ROM;
create_mapping(&map);
#endif
@@ -1426,7 +1426,11 @@ static void __init kmap_init(void)
static void __init map_lowmem(void)
{
struct memblock_region *reg;
+#ifdef CONFIG_XIP_KERNEL
+ phys_addr_t kernel_x_start = round_down(__pa(_sdata), SECTION_SIZE);
+#else
phys_addr_t kernel_x_start = round_down(__pa(_stext), SECTION_SIZE);
+#endif
phys_addr_t kernel_x_end = round_up(__pa(__init_end), SECTION_SIZE);
/* Map all the lowmem memory banks. */
diff --git a/arch/arm/mm/pageattr.c b/arch/arm/mm/pageattr.c
index cf30daff8932..d19b1ad29b07 100644
--- a/arch/arm/mm/pageattr.c
+++ b/arch/arm/mm/pageattr.c
@@ -49,6 +49,9 @@ static int change_memory_common(unsigned long addr, int numpages,
WARN_ON_ONCE(1);
}
+ if (!numpages)
+ return 0;
+
if (start < MODULES_VADDR || start >= MODULES_END)
return -EINVAL;
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 0f92d575a304..0f8963a7e7d9 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -487,7 +487,7 @@ __errata_finish:
.align 2
__v7_setup_stack_ptr:
- .word __v7_setup_stack - .
+ .word PHYS_RELATIVE(__v7_setup_stack, .)
ENDPROC(__v7_setup)
.bss
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-02 15:38:07 +0300