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Commit 98e12b5a authored by Russell King's avatar Russell King
Browse files

ARM: Fix decompressor's kernel size estimation for ROM=y 



Commit 2552fc27 changed the way the decompressor decides if it is safe
to decompress the kernel directly to its final location.  Unfortunately,
it took the top of the compressed data as being the stack pointer,
which it is for ROM=n cases.  However, for ROM=y, the stack pointer
is not relevant, and results in the wrong answer.

Fix this by explicitly storing the end of the biggybacked data in the
decompressor, and use that to calculate the compressed image size.

CC: <stable@kernel.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent baac35c4

arch/arm/boot/compressed/head.S

+23 −27
Original line number Diff line number Diff line
@@ -170,8 +170,8 @@ not_angel: 


		.text

		adr	r0, LC0

 ARM(		ldmia	r0, {r1, r2, r3, r4, r5, r6, ip, sp}	)

 THUMB(		ldmia	r0, {r1, r2, r3, r4, r5, r6, ip}	)

 ARM(		ldmia	r0, {r1, r2, r3, r4, r5, r6, r11, ip, sp})

 THUMB(		ldmia	r0, {r1, r2, r3, r4, r5, r6, r11, ip}	)

 THUMB(		ldr	sp, [r0, #28]				)

		subs	r0, r0, r1		@ calculate the delta offset
@@ -182,12 +182,13 @@ not_angel: 
		/*

		 * We're running at a different address.  We need to fix

		 * up various pointers:

		 *   r5 - zImage base address

		 *   r6 - GOT start

		 *   r5 - zImage base address (_start)

		 *   r6 - size of decompressed image

		 *   r11 - GOT start

		 *   ip - GOT end

		 */

		add	r5, r5, r0

		add	r6, r6, r0

		add	r11, r11, r0

		add	ip, ip, r0



#ifndef CONFIG_ZBOOT_ROM
@@ -205,10 +206,10 @@ not_angel: 
		/*

		 * Relocate all entries in the GOT table.

		 */

1:		ldr	r1, [r6, #0]		@ relocate entries in the GOT

1:		ldr	r1, [r11, #0]		@ relocate entries in the GOT

		add	r1, r1, r0		@ table.  This fixes up the

		str	r1, [r6], #4		@ C references.

		cmp	r6, ip

		str	r1, [r11], #4		@ C references.

		cmp	r11, ip

		blo	1b

#else
@@ -216,12 +217,12 @@ not_angel: 
		 * Relocate entries in the GOT table.  We only relocate

		 * the entries that are outside the (relocated) BSS region.

		 */

1:		ldr	r1, [r6, #0]		@ relocate entries in the GOT

1:		ldr	r1, [r11, #0]		@ relocate entries in the GOT

		cmp	r1, r2			@ entry < bss_start ||

		cmphs	r3, r1			@ _end < entry

		addlo	r1, r1, r0		@ table.  This fixes up the

		str	r1, [r6], #4		@ C references.

		cmp	r6, ip

		str	r1, [r11], #4		@ C references.

		cmp	r11, ip

		blo	1b

#endif
@@ -247,6 +248,7 @@ not_relocated: mov r0, #0 
 * Check to see if we will overwrite ourselves.

 *   r4 = final kernel address

 *   r5 = start of this image

 *   r6 = size of decompressed image

 *   r2 = end of malloc space (and therefore this image)

 * We basically want:

 *   r4 >= r2 -> OK
@@ -254,8 +256,7 @@ not_relocated: mov r0, #0 
 */

		cmp	r4, r2

		bhs	wont_overwrite

		sub	r3, sp, r5		@ > compressed kernel size

		add	r0, r4, r3, lsl #2	@ allow for 4x expansion

		add	r0, r4, r6

		cmp	r0, r5

		bls	wont_overwrite
@@ -271,7 +272,6 @@ not_relocated: mov r0, #0 
 * r1-r3  = unused

 * r4     = kernel execution address

 * r5     = decompressed kernel start

 * r6     = processor ID

 * r7     = architecture ID

 * r8     = atags pointer

 * r9-r12,r14 = corrupted
@@ -312,7 +312,8 @@ LC0: .word LC0 @ r1 
		.word	_end			@ r3

		.word	zreladdr		@ r4

		.word	_start			@ r5

		.word	_got_start		@ r6

		.word	_image_size		@ r6

		.word	_got_start		@ r11

		.word	_got_end		@ ip

		.word	user_stack+4096		@ sp

LC1:		.word	reloc_end - reloc_start
@@ -336,7 +337,6 @@ params: ldr r0, =params_phys 
 *

 * On entry,

 *  r4 = kernel execution address

 *  r6 = processor ID

 *  r7 = architecture number

 *  r8 = atags pointer

 *  r9 = run-time address of "start"  (???)
@@ -542,7 +542,6 @@ __common_mmu_cache_on: 
 * r1-r3  = unused

 * r4     = kernel execution address

 * r5     = decompressed kernel start

 * r6     = processor ID

 * r7     = architecture ID

 * r8     = atags pointer

 * r9-r12,r14 = corrupted
@@ -581,19 +580,19 @@ call_kernel: bl cache_clean_flush 
 *  r1  = corrupted

 *  r2  = corrupted

 *  r3  = block offset

 *  r6  = corrupted

 *  r9  = corrupted

 *  r12 = corrupted

 */



call_cache_fn:	adr	r12, proc_types

#ifdef CONFIG_CPU_CP15

		mrc	p15, 0, r6, c0, c0	@ get processor ID

		mrc	p15, 0, r9, c0, c0	@ get processor ID

#else

		ldr	r6, =CONFIG_PROCESSOR_ID

		ldr	r9, =CONFIG_PROCESSOR_ID

#endif

1:		ldr	r1, [r12, #0]		@ get value

		ldr	r2, [r12, #4]		@ get mask

		eor	r1, r1, r6		@ (real ^ match)

		eor	r1, r1, r9		@ (real ^ match)

		tst	r1, r2			@       & mask

 ARM(		addeq	pc, r12, r3		) @ call cache function

 THUMB(		addeq	r12, r3			)
@@ -778,8 +777,7 @@ proc_types: 
 * Turn off the Cache and MMU.  ARMv3 does not support

 * reading the control register, but ARMv4 does.

 *

 * On entry,  r6 = processor ID

 * On exit,   r0, r1, r2, r3, r12 corrupted

 * On exit, r0, r1, r2, r3, r9, r12 corrupted

 * This routine must preserve: r4, r6, r7

 */

		.align	5
@@ -852,10 +850,8 @@ __armv3_mmu_cache_off: 
/*

 * Clean and flush the cache to maintain consistency.

 *

 * On entry,

 *  r6 = processor ID

 * On exit,

 *  r1, r2, r3, r11, r12 corrupted

 *  r1, r2, r3, r9, r11, r12 corrupted

 * This routine must preserve:

 *  r0, r4, r5, r6, r7

 */
@@ -967,7 +963,7 @@ __armv4_mmu_cache_flush: 
		mov	r2, #64*1024		@ default: 32K dcache size (*2)

		mov	r11, #32		@ default: 32 byte line size

		mrc	p15, 0, r3, c0, c0, 1	@ read cache type

		teq	r3, r6			@ cache ID register present?

		teq	r3, r9			@ cache ID register present?

		beq	no_cache_id

		mov	r1, r3, lsr #18

		and	r1, r1, #7

arch/arm/boot/compressed/vmlinux.lds.in

+3 −0
Original line number Diff line number Diff line
@@ -36,6 +36,9 @@ SECTIONS 


  _etext = .;



  /* Assume size of decompressed image is 4x the compressed image */

  _image_size = (_etext - _text) * 4;



  _got_start = .;

  .got			: { *(.got) }

  _got_end = .;