x86/boot/compressed/64: Don't pre-map memory in KASLR code (8570978e) · Commits · 戴 / test

arch/x86/boot/compressed/ident_map_64.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -87,11 +87,9 @@ phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
		static struct x86_mapping_info mapping_info;

		/*
		* Adds the specified range to what will become the new identity mappings.
		* Once all ranges have been added, the new mapping is activated by calling
		* finalize_identity_maps() below.
		* Adds the specified range to the identity mappings.
		*/
		void add_identity_map(unsigned long start, unsigned long size)
		static void add_identity_map(unsigned long start, unsigned long size)
		{
		unsigned long end = start + size;

arch/x86/boot/compressed/kaslr.c

+1 −23

Original line number	Diff line number	Diff line
		@@ -397,8 +397,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
		*/
		mem_avoid[MEM_AVOID_ZO_RANGE].start = input;
		mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input;
		add_identity_map(mem_avoid[MEM_AVOID_ZO_RANGE].start,
		mem_avoid[MEM_AVOID_ZO_RANGE].size);

		/* Avoid initrd. */
		initrd_start = (u64)boot_params->ext_ramdisk_image << 32;
		@@ -416,15 +414,11 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
		cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1;
		mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line;
		mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size;
		add_identity_map(mem_avoid[MEM_AVOID_CMDLINE].start,
		mem_avoid[MEM_AVOID_CMDLINE].size);
		}

		/* Avoid boot parameters. */
		mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params;
		mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params);
		add_identity_map(mem_avoid[MEM_AVOID_BOOTPARAMS].start,
		mem_avoid[MEM_AVOID_BOOTPARAMS].size);

		/* We don't need to set a mapping for setup_data. */

		@@ -433,11 +427,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,

		/* Enumerate the immovable memory regions */
		num_immovable_mem = count_immovable_mem_regions();

		#ifdef CONFIG_X86_VERBOSE_BOOTUP
		/* Make sure video RAM can be used. */
		add_identity_map(0, PMD_SIZE);
		#endif
		}

		/*
		@@ -884,21 +873,10 @@ void choose_random_location(unsigned long input,
		warn("Physical KASLR disabled: no suitable memory region!");
		} else {
		/* Update the new physical address location. */
		if (*output != random_addr) {
		add_identity_map(random_addr, output_size);
		if (*output != random_addr)
		*output = random_addr;
		}

		/*
		* This loads the identity mapping page table.
		* This should only be done if a new physical address
		* is found for the kernel, otherwise we should keep
		* the old page table to make it be like the "nokaslr"
		* case.
		*/
		finalize_identity_maps();
		}


		/* Pick random virtual address starting from LOAD_PHYSICAL_ADDR. */
		if (IS_ENABLED(CONFIG_X86_64))

arch/x86/boot/compressed/misc.h

+0 −10

Original line number	Diff line number	Diff line
		@@ -98,17 +98,7 @@ static inline void choose_random_location(unsigned long input,
		#endif

		#ifdef CONFIG_X86_64
		void initialize_identity_maps(void);
		void add_identity_map(unsigned long start, unsigned long size);
		void finalize_identity_maps(void);
		extern unsigned char _pgtable[];
		#else
		static inline void initialize_identity_maps(void)
		{ }
		static inline void add_identity_map(unsigned long start, unsigned long size)
		{ }
		static inline void finalize_identity_maps(void)
		{ }
		#endif

		#ifdef CONFIG_EARLY_PRINTK

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