ARM: shmobile: Move shmobile_smp_{mpidr, fn, arg}[] from .text to .bss

If CONFIG_DEBUG_RODATA=y, the kernel crashes during system suspend:

    Freezing user space processes ... (elapsed 0.004 seconds) done.
    Freezing remaining freezable tasks ... (elapsed 0.002 seconds)
    done.
    PM: suspend of devices complete after 111.948 msecs
    PM: late suspend of devices complete after 1.086 msecs
    PM: noirq suspend of devices complete after 11.576 msecs
    Disabling non-boot CPUs ...
    Kernel panic - not syncing: Attempted to kill the idle task!
    1014ec ---[ end Kernel panic - not syncing: Attempted to kill the idle task!
    CPU0: stopping

This happens because the .text section is marked read-only, while the
arrays shmobile_smp_mpidr[], shmobile_smp_fn[], and shmobile_smp_arg[]
are being written to.

Fix this by moving these arrays from the .text to the .bss section.
This requires accessing them through PC-relative offsets.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

1 files changed, 14 insertions, 6 deletions

diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index 330c1fc63197..94d86ed16414 100644
--- a/arch/arm/mach-shmobile/headsmp.S
+++ b/arch/arm/mach-shmobile/headsmp.S
@@ -50,9 +50,11 @@ ENTRY(shmobile_smp_boot)
         mrc     p15, 0, r1, c0, c0, 5           @ r1 = MPIDR
         and     r0, r1, r0                      @ r0 = cpu_logical_map() value
         mov     r1, #0                          @ r1 = CPU index
-        adr     r5, 1f                          @ array of per-cpu mpidr values
-        adr     r6, 2f                          @ array of per-cpu functions
-        adr     r7, 3f                          @ array of per-cpu arguments
+        adr     r2, 1f
+        ldmia   r2, {r5, r6, r7}
+        add     r5, r5, r2                      @ array of per-cpu mpidr values
+        add     r6, r6, r2                      @ array of per-cpu functions
+        add     r7, r7, r2                      @ array of per-cpu arguments
 
 shmobile_smp_boot_find_mpidr:
         ldr     r8, [r5, r1, lsl #2]
@@ -80,12 +82,18 @@ ENTRY(shmobile_smp_sleep)
         b       shmobile_smp_boot
 ENDPROC(shmobile_smp_sleep)
 
+        .align  2
+1:      .long   shmobile_smp_mpidr - .
+        .long   shmobile_smp_fn - 1b
+        .long   shmobile_smp_arg - 1b
+
+        .bss
         .globl  shmobile_smp_mpidr
 shmobile_smp_mpidr:
-1:      .space  NR_CPUS * 4
+        .space  NR_CPUS * 4
         .globl  shmobile_smp_fn
 shmobile_smp_fn:
-2:      .space  NR_CPUS * 4
+        .space  NR_CPUS * 4
         .globl  shmobile_smp_arg
 shmobile_smp_arg:
-3:      .space  NR_CPUS * 4
+        .space  NR_CPUS * 4