Patchwork [Precise] Section mismatch warnings

login
register
mail settings
Submitter Tim Gardner
Date March 29, 2012, 1:25 p.m.
Message ID <4F7462B7.2010004@canonical.com>
Download mbox | patch
Permalink /patch/149392/
State New
Headers show

Comments

Tim Gardner - March 29, 2012, 1:25 p.m.
On 03/28/2012 11:47 PM, Tetsuo Handa wrote:
> load_elf_binary() is definitely called after initialization.

Good catch. This same issue also exists in older kernels where we've
applied the NX emulation patches.

http://bugs.launchpad.net/bugs/968233

rtg
Tetsuo Handa - March 30, 2012, 3:05 p.m.
Tim Gardner wrote:
> This is a multi-part message in MIME format.
> 
> On 03/28/2012 11:47 PM, Tetsuo Handa wrote:
> > load_elf_binary() is definitely called after initialization.
> 
> Good catch. This same issue also exists in older kernels where we've
> applied the NX emulation patches.

OK. Then, I think we also want to fix these warnings probably introduced by
commit a6021559 "UBUNTU: SAUCE: (no-up) Modularize vesafb".

WARNING: drivers/video/vesafb.o(.exit.text+0x42): Section mismatch in reference from the function vesafb_remove() to the (unknown reference) .init.data:(unknown)
The function __exit vesafb_remove() references
a (unknown reference) __initdata (unknown).
This is often seen when error handling in the exit function
uses functionality in the init path.
The fix is often to remove the __initdata annotation of
(unknown) so it may be used outside an init section.

WARNING: drivers/video/vesafb.o(.exit.text+0x4a): Section mismatch in reference from the function vesafb_remove() to the variable .init.data:vesafb_fix
The function __exit vesafb_remove() references
a variable __initdata vesafb_fix.
This is often seen when error handling in the exit function
uses functionality in the init path.
The fix is often to remove the __initdata annotation of
vesafb_fix so it may be used outside an init section.



  49 static struct fb_fix_screeninfo vesafb_fix __initdata = {
  50         .id     = "VESA VGA",
  51         .type   = FB_TYPE_PACKED_PIXELS,
  52         .accel  = FB_ACCEL_NONE,
  53 };

 527 static int __exit vesafb_remove(struct platform_device *device)
 528 {
 529         struct fb_info *info = dev_get_drvdata(&device->dev);
 530 
 531         unregister_framebuffer(info);
 532 #ifdef CONFIG_MTRR
 533         {
 534                 struct vesafb_info *vfb_info = (struct vesafb_info *) info->par;
 535                 if (vfb_info->mtrr_hdl >= 0)
 536                         mtrr_del(vfb_info->mtrr_hdl, 0, 0);
 537         }
 538 #endif
 539         iounmap(info->screen_base);
 540         framebuffer_release(info);
 541         release_mem_region(vesafb_fix.smem_start, vesafb_fix.smem_len);
                                           |                      |
                              These values are no longer valid upon unloading.
 542 
 543         return 0;
 544 }
Tim Gardner - March 30, 2012, 3:39 p.m.
BugLink: http://bugs.launchpad.net/bugs/969309

I guess I ought to do a more exhaustive audit for these section
mismatches. It makes me wonder why we haven't had more problems with
section mismatches.

rtg

Patch

From e540f21852043a4d8e8cf5e505607909d0ab0f51 Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner@canonical.com>
Date: Thu, 29 Mar 2012 06:21:01 -0600
Subject: [PATCH] UBUNTU: SAUCE: disable_nx should not be in __cpuinitdata
 section for X86_32

I noticed a section mismatch warning while building 3.2.0-20.33 for X86_32.

 AR      arch/x86/lib/lib.a
  LD      vmlinux.o
  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x187833): Section mismatch in reference from the function load_elf_binary() to the variable .cpuinit.data:disable_nx
The function load_elf_binary() references
the variable __cpuinitdata disable_nx.
This is often because load_elf_binary lacks a __cpuinitdata
annotation or the annotation of disable_nx is wrong.

load_elf_binary() is definitely called after initialization.

This code was added by 'UBUNTU: ubuntu: nx-emu - i386: NX emulation', so
this is not an upstream problem.

Reported-by: Tetsuo Handa <from-ubuntu@I-love.SAKURA.ne.jp>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
---
 arch/x86/mm/setup_nx.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/arch/x86/mm/setup_nx.c b/arch/x86/mm/setup_nx.c
index 90c9eff3..89fd946 100644
--- a/arch/x86/mm/setup_nx.c
+++ b/arch/x86/mm/setup_nx.c
@@ -6,7 +6,11 @@ 
 #include <asm/pgtable.h>
 #include <asm/proto.h>
 
+#ifdef CONFIG_X86_32
+int disable_nx; /* referenced by load_elf_binary() */
+#else
 int disable_nx __cpuinitdata;
+#endif
 
 /*
  * noexec = on|off
-- 
1.7.9.1