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-rw-r--r--arch/arm64/mm/init.c134
1 files changed, 112 insertions, 22 deletions
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3b061e67bfe..61a38eaf0895 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -35,7 +35,10 @@
#include <linux/efi.h>
#include <linux/swiotlb.h>
+#include <asm/boot.h>
#include <asm/fixmap.h>
+#include <asm/kasan.h>
+#include <asm/kernel-pgtable.h>
#include <asm/memory.h>
#include <asm/sections.h>
#include <asm/setup.h>
@@ -45,7 +48,13 @@
#include "mm.h"
-phys_addr_t memstart_addr __read_mostly = 0;
+/*
+ * We need to be able to catch inadvertent references to memstart_addr
+ * that occur (potentially in generic code) before arm64_memblock_init()
+ * executes, which assigns it its actual value. So use a default value
+ * that cannot be mistaken for a real physical address.
+ */
+s64 memstart_addr __read_mostly = -1;
phys_addr_t arm64_dma_phys_limit __read_mostly;
#ifdef CONFIG_BLK_DEV_INITRD
@@ -58,8 +67,8 @@ static int __init early_initrd(char *p)
if (*endp == ',') {
size = memparse(endp + 1, NULL);
- initrd_start = (unsigned long)__va(start);
- initrd_end = (unsigned long)__va(start + size);
+ initrd_start = start;
+ initrd_end = start + size;
}
return 0;
}
@@ -159,7 +168,57 @@ early_param("mem", early_mem);
void __init arm64_memblock_init(void)
{
- memblock_enforce_memory_limit(memory_limit);
+ const s64 linear_region_size = -(s64)PAGE_OFFSET;
+
+ /*
+ * Ensure that the linear region takes up exactly half of the kernel
+ * virtual address space. This way, we can distinguish a linear address
+ * from a kernel/module/vmalloc address by testing a single bit.
+ */
+ BUILD_BUG_ON(linear_region_size != BIT(VA_BITS - 1));
+
+ /*
+ * Select a suitable value for the base of physical memory.
+ */
+ memstart_addr = round_down(memblock_start_of_DRAM(),
+ ARM64_MEMSTART_ALIGN);
+
+ /*
+ * Remove the memory that we will not be able to cover with the
+ * linear mapping. Take care not to clip the kernel which may be
+ * high in memory.
+ */
+ memblock_remove(max_t(u64, memstart_addr + linear_region_size, __pa(_end)),
+ ULLONG_MAX);
+ if (memblock_end_of_DRAM() > linear_region_size)
+ memblock_remove(0, memblock_end_of_DRAM() - linear_region_size);
+
+ /*
+ * Apply the memory limit if it was set. Since the kernel may be loaded
+ * high up in memory, add back the kernel region that must be accessible
+ * via the linear mapping.
+ */
+ if (memory_limit != (phys_addr_t)ULLONG_MAX) {
+ memblock_enforce_memory_limit(memory_limit);
+ memblock_add(__pa(_text), (u64)(_end - _text));
+ }
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ extern u16 memstart_offset_seed;
+ u64 range = linear_region_size -
+ (memblock_end_of_DRAM() - memblock_start_of_DRAM());
+
+ /*
+ * If the size of the linear region exceeds, by a sufficient
+ * margin, the size of the region that the available physical
+ * memory spans, randomize the linear region as well.
+ */
+ if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
+ range = range / ARM64_MEMSTART_ALIGN + 1;
+ memstart_addr -= ARM64_MEMSTART_ALIGN *
+ ((range * memstart_offset_seed) >> 16);
+ }
+ }
/*
* Register the kernel text, kernel data, initrd, and initial
@@ -167,8 +226,13 @@ void __init arm64_memblock_init(void)
*/
memblock_reserve(__pa(_text), _end - _text);
#ifdef CONFIG_BLK_DEV_INITRD
- if (initrd_start)
- memblock_reserve(__virt_to_phys(initrd_start), initrd_end - initrd_start);
+ if (initrd_start) {
+ memblock_reserve(initrd_start, initrd_end - initrd_start);
+
+ /* the generic initrd code expects virtual addresses */
+ initrd_start = __phys_to_virt(initrd_start);
+ initrd_end = __phys_to_virt(initrd_end);
+ }
#endif
early_init_fdt_scan_reserved_mem();
@@ -302,35 +366,38 @@ void __init mem_init(void)
#ifdef CONFIG_KASAN
" kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
#endif
+ " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
+ " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
+ " .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
#ifdef CONFIG_SPARSEMEM_VMEMMAP
" vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
" 0x%16lx - 0x%16lx (%6ld MB actual)\n"
#endif
" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
" PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
- " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
- " memory : 0x%16lx - 0x%16lx (%6ld MB)\n"
- " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
- " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
- " .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ " memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
#ifdef CONFIG_KASAN
MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
#endif
+ MLM(MODULES_VADDR, MODULES_END),
MLG(VMALLOC_START, VMALLOC_END),
+ MLK_ROUNDUP(_text, __start_rodata),
+ MLK_ROUNDUP(__start_rodata, _etext),
+ MLK_ROUNDUP(__init_begin, __init_end),
+ MLK_ROUNDUP(_sdata, _edata),
#ifdef CONFIG_SPARSEMEM_VMEMMAP
- MLG((unsigned long)vmemmap,
- (unsigned long)vmemmap + VMEMMAP_SIZE),
- MLM((unsigned long)virt_to_page(PAGE_OFFSET),
+ MLG(VMEMMAP_START,
+ VMEMMAP_START + VMEMMAP_SIZE),
+ MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()),
(unsigned long)virt_to_page(high_memory)),
#endif
MLK(FIXADDR_START, FIXADDR_TOP),
MLM(PCI_IO_START, PCI_IO_END),
- MLM(MODULES_VADDR, MODULES_END),
- MLM(PAGE_OFFSET, (unsigned long)high_memory),
- MLK_ROUNDUP(__init_begin, __init_end),
- MLK_ROUNDUP(_text, _etext),
- MLK_ROUNDUP(_sdata, _edata));
+ MLM(__phys_to_virt(memblock_start_of_DRAM()),
+ (unsigned long)high_memory));
#undef MLK
#undef MLM
@@ -343,8 +410,6 @@ void __init mem_init(void)
#ifdef CONFIG_COMPAT
BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
#endif
- BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
- BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
extern int sysctl_overcommit_memory;
@@ -358,8 +423,8 @@ void __init mem_init(void)
void free_initmem(void)
{
- fixup_init();
free_initmem_default(0);
+ fixup_init();
}
#ifdef CONFIG_BLK_DEV_INITRD
@@ -380,3 +445,28 @@ static int __init keepinitrd_setup(char *__unused)
__setup("keepinitrd", keepinitrd_setup);
#endif
+
+/*
+ * Dump out memory limit information on panic.
+ */
+static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
+{
+ if (memory_limit != (phys_addr_t)ULLONG_MAX) {
+ pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
+ } else {
+ pr_emerg("Memory Limit: none\n");
+ }
+ return 0;
+}
+
+static struct notifier_block mem_limit_notifier = {
+ .notifier_call = dump_mem_limit,
+};
+
+static int __init register_mem_limit_dumper(void)
+{
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &mem_limit_notifier);
+ return 0;
+}
+__initcall(register_mem_limit_dumper);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.