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-rw-r--r--arch/arm64/kernel/machine_kexec.c32
-rw-r--r--arch/arm64/mm/mmu.c103
2 files changed, 80 insertions, 55 deletions
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index bc96c8a7fc79..b63baa749609 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -14,7 +14,9 @@
#include <asm/cacheflush.h>
#include <asm/cpu_ops.h>
+#include <asm/mmu.h>
#include <asm/mmu_context.h>
+#include <asm/page.h>
#include "cpu-reset.h"
@@ -22,8 +24,6 @@
extern const unsigned char arm64_relocate_new_kernel[];
extern const unsigned long arm64_relocate_new_kernel_size;
-static unsigned long kimage_start;
-
/**
* kexec_image_info - For debugging output.
*/
@@ -64,8 +64,6 @@ void machine_kexec_cleanup(struct kimage *kimage)
*/
int machine_kexec_prepare(struct kimage *kimage)
{
- kimage_start = kimage->start;
-
kexec_image_info(kimage);
if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
@@ -183,7 +181,7 @@ void machine_kexec(struct kimage *kimage)
kexec_list_flush(kimage);
/* Flush the new image if already in place. */
- if (kimage->head & IND_DONE)
+ if ((kimage != kexec_crash_image) && (kimage->head & IND_DONE))
kexec_segment_flush(kimage);
pr_info("Bye!\n");
@@ -201,7 +199,7 @@ void machine_kexec(struct kimage *kimage)
*/
cpu_soft_restart(1, reboot_code_buffer_phys, kimage->head,
- kimage_start, 0);
+ kimage->start, 0);
BUG(); /* Should never get here. */
}
@@ -210,3 +208,25 @@ void machine_crash_shutdown(struct pt_regs *regs)
{
/* Empty routine needed to avoid build errors. */
}
+
+void arch_kexec_protect_crashkres(void)
+{
+ int i;
+
+ kexec_segment_flush(kexec_crash_image);
+
+ for (i = 0; i < kexec_crash_image->nr_segments; i++)
+ set_memory_valid(
+ __phys_to_virt(kexec_crash_image->segment[i].mem),
+ kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 0);
+}
+
+void arch_kexec_unprotect_crashkres(void)
+{
+ int i;
+
+ for (i = 0; i < kexec_crash_image->nr_segments; i++)
+ set_memory_valid(
+ __phys_to_virt(kexec_crash_image->segment[i].mem),
+ kexec_crash_image->segment[i].memsz >> PAGE_SHIFT, 1);
+}
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 91502e36e6d9..0c429ec6fde8 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -22,6 +22,8 @@
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/kexec.h>
#include <linux/libfdt.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
@@ -393,10 +395,28 @@ static void update_mapping_prot(phys_addr_t phys, unsigned long virt,
flush_tlb_kernel_range(virt, virt + size);
}
-static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end)
+static void __init __map_memblock(pgd_t *pgd, phys_addr_t start,
+ phys_addr_t end, pgprot_t prot, int flags)
+{
+ __create_pgd_mapping(pgd, start, __phys_to_virt(start), end - start,
+ prot, early_pgtable_alloc, flags);
+}
+
+void __init mark_linear_text_alias_ro(void)
+{
+ /*
+ * Remove the write permissions from the linear alias of .text/.rodata
+ */
+ update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text),
+ (unsigned long)__init_begin - (unsigned long)_text,
+ PAGE_KERNEL_RO);
+}
+
+static void __init map_mem(pgd_t *pgd)
{
phys_addr_t kernel_start = __pa_symbol(_text);
phys_addr_t kernel_end = __pa_symbol(__init_begin);
+ struct memblock_region *reg;
int flags = 0;
if (debug_pagealloc_enabled())
@@ -405,30 +425,28 @@ static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end
/*
* Take care not to create a writable alias for the
* read-only text and rodata sections of the kernel image.
+ * So temporarily mark them as NOMAP to skip mappings in
+ * the following for-loop
*/
+ memblock_mark_nomap(kernel_start, kernel_end - kernel_start);
+#ifdef CONFIG_KEXEC_CORE
+ if (crashk_res.end)
+ memblock_mark_nomap(crashk_res.start,
+ resource_size(&crashk_res));
+#endif
- /* No overlap with the kernel text/rodata */
- if (end < kernel_start || start >= kernel_end) {
- __create_pgd_mapping(pgd, start, __phys_to_virt(start),
- end - start, PAGE_KERNEL,
- early_pgtable_alloc, flags);
- return;
- }
+ /* map all the memory banks */
+ for_each_memblock(memory, reg) {
+ phys_addr_t start = reg->base;
+ phys_addr_t end = start + reg->size;
- /*
- * This block overlaps the kernel text/rodata mappings.
- * Map the portion(s) which don't overlap.
- */
- if (start < kernel_start)
- __create_pgd_mapping(pgd, start,
- __phys_to_virt(start),
- kernel_start - start, PAGE_KERNEL,
- early_pgtable_alloc, flags);
- if (kernel_end < end)
- __create_pgd_mapping(pgd, kernel_end,
- __phys_to_virt(kernel_end),
- end - kernel_end, PAGE_KERNEL,
- early_pgtable_alloc, flags);
+ if (start >= end)
+ break;
+ if (memblock_is_nomap(reg))
+ continue;
+
+ __map_memblock(pgd, start, end, PAGE_KERNEL, flags);
+ }
/*
* Map the linear alias of the [_text, __init_begin) interval
@@ -440,37 +458,24 @@ static void __init __map_memblock(pgd_t *pgd, phys_addr_t start, phys_addr_t end
* Note that contiguous mappings cannot be remapped in this way,
* so we should avoid them here.
*/
- __create_pgd_mapping(pgd, kernel_start, __phys_to_virt(kernel_start),
- kernel_end - kernel_start, PAGE_KERNEL,
- early_pgtable_alloc, NO_CONT_MAPPINGS);
-}
+ __map_memblock(pgd, kernel_start, kernel_end,
+ PAGE_KERNEL, NO_CONT_MAPPINGS);
+ memblock_clear_nomap(kernel_start, kernel_end - kernel_start);
-void __init mark_linear_text_alias_ro(void)
-{
+#ifdef CONFIG_KEXEC_CORE
/*
- * Remove the write permissions from the linear alias of .text/.rodata
+ * Use page-level mappings here so that we can shrink the region
+ * in page granularity and put back unused memory to buddy system
+ * through /sys/kernel/kexec_crash_size interface.
*/
- update_mapping_prot(__pa_symbol(_text), (unsigned long)lm_alias(_text),
- (unsigned long)__init_begin - (unsigned long)_text,
- PAGE_KERNEL_RO);
-}
-
-static void __init map_mem(pgd_t *pgd)
-{
- struct memblock_region *reg;
-
- /* map all the memory banks */
- for_each_memblock(memory, reg) {
- phys_addr_t start = reg->base;
- phys_addr_t end = start + reg->size;
-
- if (start >= end)
- break;
- if (memblock_is_nomap(reg))
- continue;
-
- __map_memblock(pgd, start, end);
+ if (crashk_res.end) {
+ __map_memblock(pgd, crashk_res.start, crashk_res.end + 1,
+ PAGE_KERNEL,
+ NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS);
+ memblock_clear_nomap(crashk_res.start,
+ resource_size(&crashk_res));
}
+#endif
}
void mark_rodata_ro(void)
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-12 13:04:34 +0300