[V3] ARM: add missing linker section markup to head-common.S

Commit Message

Stephen Warren July 5, 2013, 6:10 p.m. UTC

From: Stephen Warren <[e-mail]>

Macro __INIT is used to place various code in head-common.S into the init
section. This should be matched by a closing __FINIT. Also, add an
explicit ".text" to ensure subsequent code is placed into the correct
section; __FINIT is simply a closing marker to match __INIT and doesn't
guarantee to revert to .text.

This historically caused no problem, because macro __CPUINIT was used at
the exact location where __FINIT was missing, which then placed following
code into the cpuinit section. However, with commit 22f0a2736 "init.h:
remove __cpuinit sections from the kernel" applied, __CPUINIT becomes a
no-op, thus leaving all this code in the init section, rather than the
regular text section. This caused issues such as secondary CPU boot
failures or crashes.

Signed-off-by: Stephen Warren <[e-mail]>
Acked-by: Paul Gortmaker <[e-mail]>
---
v3: Added .text after __FINIT to force the correct section.
v2: Moved __FINIT after lookup_processor_type, to correctly match the
location of __CPUINIT.
---
 arch/arm/kernel/head-common.S | 3 +++
 1 file changed, 3 insertions(+)

Comments

Russell King - ARM Linux July 5, 2013, 9:32 p.m. UTC | #1

On Fri, Jul 05, 2013 at 12:10:55PM -0600, Stephen Warren wrote:
> From: Stephen Warren <[e-mail]>
> 
> Macro __INIT is used to place various code in head-common.S into the init
> section. This should be matched by a closing __FINIT. Also, add an
> explicit ".text" to ensure subsequent code is placed into the correct
> section; __FINIT is simply a closing marker to match __INIT and doesn't
> guarantee to revert to .text.
> 
> This historically caused no problem, because macro __CPUINIT was used at
> the exact location where __FINIT was missing, which then placed following
> code into the cpuinit section. However, with commit 22f0a2736 "init.h:
> remove __cpuinit sections from the kernel" applied, __CPUINIT becomes a
> no-op, thus leaving all this code in the init section, rather than the
> regular text section. This caused issues such as secondary CPU boot
> failures or crashes.
> 
> Signed-off-by: Stephen Warren <[e-mail]>
> Acked-by: Paul Gortmaker <[e-mail]>
> ---
> v3: Added .text after __FINIT to force the correct section.
> v2: Moved __FINIT after lookup_processor_type, to correctly match the
> location of __CPUINIT.

Much better, thanks.  Please put it in the patch system and I'll send it
along, thanks.

Patch

diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S
index 529ce99..47cd974 100644
--- a/arch/arm/kernel/head-common.S
+++ b/arch/arm/kernel/head-common.S
@@ -133,6 +133,9 @@  ENTRY(lookup_processor_type)
 	ldmfd	sp!, {r4 - r6, r9, pc}
 ENDPROC(lookup_processor_type)
 
+	__FINIT
+	.text
+
 /*
  * Read processor ID register (CP#15, CR0), and look up in the linker-built
  * supported processor list.  Note that we can't use the absolute addresses