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Subject[004/116] ARM: Fix decompressors kernel size estimation for ROM=y
2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Russell King <rmk+kernel@arm.linux.org.uk>

commit 98e12b5a6e05413420a7e3b3eca7fbfc2ff41b6d upstream.

Commit 2552fc2 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.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/arm/boot/compressed/head.S | 50 ++++++++++++++------------------
arch/arm/boot/compressed/vmlinux.lds.in | 3 +
2 files changed, 26 insertions(+), 27 deletions(-)

--- a/arch/arm/boot/compressed/head.S
+++ b/arch/arm/boot/compressed/head.S
@@ -162,8 +162,8 @@ 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

@@ -174,12 +174,13 @@ 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
@@ -197,10 +198,10 @@ 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

@@ -208,12 +209,12 @@ 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

@@ -239,6 +240,7 @@ 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
@@ -246,8 +248,7 @@ 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

@@ -263,7 +264,6 @@ 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
@@ -304,7 +304,8 @@ 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
@@ -328,7 +329,6 @@ 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" (???)
@@ -534,7 +534,6 @@ __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
@@ -573,19 +572,19 @@ 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 )
@@ -764,8 +763,7 @@ 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
@@ -838,10 +836,8 @@ __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
*/
@@ -953,7 +949,7 @@ __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
--- a/arch/arm/boot/compressed/vmlinux.lds.in
+++ b/arch/arm/boot/compressed/vmlinux.lds.in
@@ -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 = .;



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