Commit a1d2d9cb authored by Vasily Gorbik's avatar Vasily Gorbik
Browse files

s390/boot: do not change default_lma 



The current modification of the default_lma is illogical and should be
avoided. It would be more appropriate to introduce and utilize a new
variable vmlinux_lma instead, so that default_lma remains unchanged and
at its original "default" value of 0x100000.

Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 26300860

arch/s390/boot/startup.c

+12 −13
Original line number Diff line number Diff line
@@ -235,9 +235,9 @@ static unsigned long setup_kernel_memory_layout(void) 
/*

 * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's.

 */

static void clear_bss_section(void)

static void clear_bss_section(unsigned long vmlinux_lma)

{

	memset((void *)vmlinux.default_lma + vmlinux.image_size, 0, vmlinux.bss_size);

	memset((void *)vmlinux_lma + vmlinux.image_size, 0, vmlinux.bss_size);

}



/*
@@ -256,7 +256,6 @@ static void setup_vmalloc_size(void) 


static void offset_vmlinux_info(unsigned long offset)

{

	vmlinux.default_lma += offset;

	*(unsigned long *)(&vmlinux.entry) += offset;

	vmlinux.bootdata_off += offset;

	vmlinux.bootdata_preserved_off += offset;
@@ -278,7 +277,7 @@ static void offset_vmlinux_info(unsigned long offset) 
void startup_kernel(void)

{

	unsigned long max_physmem_end;

	unsigned long random_lma;

	unsigned long vmlinux_lma = 0;

	unsigned long asce_limit;

	unsigned long safe_addr;

	void *img;
@@ -316,26 +315,26 @@ void startup_kernel(void) 
	rescue_initrd(safe_addr, ident_map_size);



	if (kaslr_enabled()) {

		random_lma = get_random_base();

		if (random_lma) {

			__kaslr_offset = random_lma - vmlinux.default_lma;

			img = (void *)vmlinux.default_lma;

		vmlinux_lma = get_random_base();

		if (vmlinux_lma) {

			__kaslr_offset = vmlinux_lma - vmlinux.default_lma;

			offset_vmlinux_info(__kaslr_offset);

		}

	}

	vmlinux_lma = vmlinux_lma ?: vmlinux.default_lma;

	physmem_reserve(RR_VMLINUX, vmlinux_lma, vmlinux.image_size + vmlinux.bss_size);



	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {

		img = decompress_kernel();

		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);

		memmove((void *)vmlinux_lma, img, vmlinux.image_size);

	} else if (__kaslr_offset) {

		memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);

		img = (void *)vmlinux.default_lma;

		memmove((void *)vmlinux_lma, img, vmlinux.image_size);

		memset(img, 0, vmlinux.image_size);

	}



	/* vmlinux decompression is done, shrink reserved low memory */

	physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end);

	if (!__kaslr_offset)

		physmem_reserve(RR_VMLINUX, vmlinux.default_lma, vmlinux.image_size + vmlinux.bss_size);

	physmem_alloc_range(RR_AMODE31, vmlinux.amode31_size, PAGE_SIZE, 0, SZ_2G, true);



	/*
@@ -351,7 +350,7 @@ void startup_kernel(void) 
	 * - copy_bootdata() must follow setup_vmem() to propagate changes to

	 *   bootdata made by setup_vmem()

	 */

	clear_bss_section();

	clear_bss_section(vmlinux_lma);

	handle_relocs(__kaslr_offset);

	setup_vmem(asce_limit);

	copy_bootdata();