x86/kaslr: Make command line handling safer (709709ac) · Commits · 戴 / test

arch/x86/boot/compressed/kaslr.c

+14 −12

Original line number	Diff line number	Diff line
		@@ -268,15 +268,19 @@ static void parse_gb_huge_pages(char param, char val)
		static void handle_mem_options(void)
		{
		char args = (char )get_cmd_line_ptr();
		size_t len = strlen((char *)args);
		size_t len;
		char *tmp_cmdline;
		char param, val;
		u64 mem_size;

		if (!args)
		return;

		if (!strstr(args, "memmap=") && !strstr(args, "mem=") &&
		!strstr(args, "hugepages"))
		return;

		len = strlen(args);
		tmp_cmdline = malloc(len + 1);
		if (!tmp_cmdline)
		error("Failed to allocate space for tmp_cmdline");
		@@ -399,8 +403,7 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
		{
		unsigned long init_size = boot_params->hdr.init_size;
		u64 initrd_start, initrd_size;
		u64 cmd_line, cmd_line_size;
		char *ptr;
		unsigned long cmd_line, cmd_line_size;

		/*
		* Avoid the region that is unsafe to overlap during
		@@ -421,16 +424,15 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
		/* No need to set mapping for initrd, it will be handled in VO. */

		/* Avoid kernel command line. */
		cmd_line = (u64)boot_params->ext_cmd_line_ptr << 32;
		cmd_line \|= boot_params->hdr.cmd_line_ptr;
		cmd_line = get_cmd_line_ptr();
		/* Calculate size of cmd_line. */
		ptr = (char *)(unsigned long)cmd_line;
		for (cmd_line_size = 0; ptr[cmd_line_size++];)
		;
		if (cmd_line) {
		cmd_line_size = strlen((char *)cmd_line) + 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;

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