Commit 4e960f52 authored Feb 15, 2016 by Geert Uytterhoeven Committed by Simon Horman Feb 17, 2016

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>

parent b1568d80

arch/arm/mach-shmobile/headsmp.S

+14 −6

Original line number	Diff line number	Diff line
		@@ -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