ARM: use linker magic for vectors and vector stubs
authorRussell King <rmk+kernel@arm.linux.org.uk>
Thu, 4 Jul 2013 11:03:31 +0000 (12:03 +0100)
committerRussell King <rmk+kernel@arm.linux.org.uk>
Wed, 31 Jul 2013 20:34:24 +0000 (21:34 +0100)
Use linker magic to create the vectors and vector stubs: we can tell the
linker to place them at an appropriate VMA, but keep the LMA within the
kernel.  This gets rid of some unnecessary symbol manipulation, and
have the linker calculate the relocations appropriately.

Cc: <stable@vger.kernel.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arch/arm/kernel/entry-armv.S
arch/arm/kernel/vmlinux.lds.S

index 79a41fa978f56e191f5c30952c9863e4dc8ae92b..7e1ae91e5b1a96f4e398a43d95d57bc10f6677cd 100644 (file)
@@ -993,7 +993,7 @@ ENDPROC(vector_\name)
 1:
        .endm
 
-       .globl  __stubs_start
+       .section .stubs, "ax", %progbits
 __stubs_start:
        @ This must be the first word
        .word   vector_swi
@@ -1120,24 +1120,16 @@ vector_addrexcptn:
 vector_fiq:
        subs    pc, lr, #4
 
-       .globl  __stubs_end
-__stubs_end:
-
-       .equ    stubs_offset, __vectors_start + 0x1000 - __stubs_start
-
-       .globl  __vectors_start
+       .section .vectors, "ax", %progbits
 __vectors_start:
-       W(b)    vector_rst + stubs_offset
-       W(b)    vector_und + stubs_offset
-       W(ldr)  pc, .LCvswi + stubs_offset
-       W(b)    vector_pabt + stubs_offset
-       W(b)    vector_dabt + stubs_offset
-       W(b)    vector_addrexcptn + stubs_offset
-       W(b)    vector_irq + stubs_offset
-       W(b)    vector_fiq + stubs_offset
-
-       .globl  __vectors_end
-__vectors_end:
+       W(b)    vector_rst
+       W(b)    vector_und
+       W(ldr)  pc, __vectors_start + 0x1000
+       W(b)    vector_pabt
+       W(b)    vector_dabt
+       W(b)    vector_addrexcptn
+       W(b)    vector_irq
+       W(b)    vector_fiq
 
        .data
 
index fa25e4e425f6070c0a6055de98271f865dde3823..7bcee5c9b6049c2723df9e3e9fc9b0b088b5fe0b 100644 (file)
@@ -148,6 +148,23 @@ SECTIONS
        . = ALIGN(PAGE_SIZE);
        __init_begin = .;
 #endif
+       /*
+        * The vectors and stubs are relocatable code, and the
+        * only thing that matters is their relative offsets
+        */
+       __vectors_start = .;
+       .vectors 0 : AT(__vectors_start) {
+               *(.vectors)
+       }
+       . = __vectors_start + SIZEOF(.vectors);
+       __vectors_end = .;
+
+       __stubs_start = .;
+       .stubs 0x1000 : AT(__stubs_start) {
+               *(.stubs)
+       }
+       . = __stubs_start + SIZEOF(.stubs);
+       __stubs_end = .;
 
        INIT_TEXT_SECTION(8)
        .exit.text : {