[ARM] VFP: fix section mismatch error

Fix a real section mismatch issue; the test code is thrown away after
initialisation, but if we do not detect the VFP hardware, it is left
hooked into the exception handler.  Any VFP instructions which are
subsequently executed risk calling the discarded exception handler.

Introduce a new "null" handler which returns to the "unrecognised
fault" return address.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index ca2a5ad..806ce26 100644 (file)
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -29,6 +29,10 @@ do_vfp:
        add     r10, r10, #TI_VFPSTATE  @ r10 = workspace
        ldr     pc, [r4]                @ call VFP entry point
 
+ENTRY(vfp_null_entry)
+       mov     pc, lr
+ENDPROC(vfp_null_entry)
+
 .LCvfp:
        .word   vfp_vector
 

diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index f1e5951..1106b5f 100644 (file)
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -26,8 +26,9 @@
  */
 void vfp_testing_entry(void);
 void vfp_support_entry(void);
+void vfp_null_entry(void);
 
-void (*vfp_vector)(void) = vfp_testing_entry;
+void (*vfp_vector)(void) = vfp_null_entry;
 union vfp_state *last_VFP_context[NR_CPUS];
 
 /*
@@ -321,8 +322,10 @@ static int __init vfp_init(void)
         * The handler is already setup to just log calls, so
         * we just need to read the VFPSID register.
         */
+       vfp_vector = vfp_testing_entry;
        vfpsid = fmrx(FPSID);
        barrier();
+       vfp_vector = vfp_null_entry;
 
        printk(KERN_INFO "VFP support v0.3: ");
        if (VFP_arch) {

diff --git a/include/asm-arm/linkage.h b/include/asm-arm/linkage.h
index dbe4b4e..5a25632 100644 (file)
--- a/include/asm-arm/linkage.h
+++ b/include/asm-arm/linkage.h
@@ -4,4 +4,8 @@
 #define __ALIGN .align 0
 #define __ALIGN_STR ".align 0"
 
+#define ENDPROC(name) \
+  .type name, %function; \
+  END(name)
+
 #endif