ARM: 7325/1: fix v7 boot with lockdep enabled

commit 8e43a905dd574f54c5715d978318290ceafbe275 upstream.

Bootup with lockdep enabled has been broken on v7 since b46c0f74657d
("ARM: 7321/1: cache-v7: Disable preemption when reading CCSIDR").

This is because v7_setup (which is called very early during boot) calls
v7_flush_dcache_all, and the save_and_disable_irqs added by that patch
ends up attempting to call into lockdep C code (trace_hardirqs_off())
when we are in no position to execute it (no stack, MMU off).

Fix this by using a notrace variant of save_and_disable_irqs.  The code
already uses the notrace variant of restore_irqs.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 29035e8..7bb8bf9 100644 (file)
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -137,6 +137,11 @@
        disable_irq
        .endm
 
+       .macro  save_and_disable_irqs_notrace, oldcpsr
+       mrs     \oldcpsr, cpsr
+       disable_irq_notrace
+       .endm
+
 /*
  * Restore interrupt state previously stored in a register.  We don't
  * guarantee that this will preserve the flags.

diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 7a24d39..a655d3d 100644 (file)
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -55,7 +55,7 @@ loop1:
        cmp     r1, #2                          @ see what cache we have at this level
        blt     skip                            @ skip if no cache, or just i-cache
 #ifdef CONFIG_PREEMPT
-       save_and_disable_irqs r9                @ make cssr&csidr read atomic
+       save_and_disable_irqs_notrace r9        @ make cssr&csidr read atomic
 #endif
        mcr     p15, 2, r10, c0, c0, 0          @ select current cache level in cssr
        isb                                     @ isb to sych the new cssr&csidr