[PATCH 1/3] xen: events: mark cpu_evtchn_mask_p as __refdata

[PATCH 1/3] xen: events: mark cpu_evtchn_mask_p as __refdata

[Ian Campbell]

This variable starts out pointing at init_evtchn_mask which is marked
__initdata but is set to point to a non-init data region in xen_init_IRQ
which is itself an __init function so this is safe.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Tested-and-acked-by: Andrew Jones <drjones@redhat.com>
---
 drivers/xen/events.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 51051cf..d88702e 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -114,7 +114,7 @@ struct cpu_evtchn_s {
 static __initdata struct cpu_evtchn_s init_evtchn_mask = {
 	.bits[0 ... (NR_EVENT_CHANNELS/BITS_PER_LONG)-1] = ~0ul,
 };
-static struct cpu_evtchn_s *cpu_evtchn_mask_p = &init_evtchn_mask;
+static struct cpu_evtchn_s __refdata *cpu_evtchn_mask_p = &init_evtchn_mask;
 
 static inline unsigned long *cpu_evtchn_mask(int cpu)
 {
-- 
1.5.6.5

[PATCH 2/3] xen: annotate functions which only call into __init at start of day

[Ian Campbell]

Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be
called at resume time as well as at start of day but only reference
__init functions (extend_brk) at start of day. Hence annotate with
__refdata.

    WARNING: arch/x86/built-in.o(.text+0x4f1): Section mismatch in reference
        from the function xen_hvm_init_shared_info() to the function
        .init.text:extend_brk()
    The function xen_hvm_init_shared_info() references
    the function __init extend_brk().
    This is often because xen_hvm_init_shared_info lacks a __init
    annotation or the annotation of extend_brk is wrong.

xen_hvm_init_shared_info calls extend_brk() iff !shared_info_page and
initialises shared_info_page with the result. This happens at start of
day only.

    WARNING: arch/x86/built-in.o(.text+0x599b): Section mismatch in reference
        from the function xen_build_mfn_list_list() to the function
        .init.text:extend_brk()
    The function xen_build_mfn_list_list() references
    the function __init extend_brk().
    This is often because xen_build_mfn_list_list lacks a __init
    annotation or the annotation of extend_brk is wrong.

(this warning occurs multiple times)

xen_build_mfn_list_list only calls extend_brk() at boot time, while
building the initial mfn list list

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 arch/x86/xen/enlighten.c |    2 +-
 arch/x86/xen/p2m.c       |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 50542ef..f4195fa 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1292,7 +1292,7 @@ static int init_hvm_pv_info(int *major, int *minor)
 	return 0;
 }
 
-void xen_hvm_init_shared_info(void)
+void __refdata xen_hvm_init_shared_info(void)
 {
 	int cpu;
 	struct xen_add_to_physmap xatp;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index fd12d7c..53fe9fc 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -136,7 +136,7 @@ static void p2m_init(unsigned long *p2m)
  * - After resume we're called from within stop_machine, but the mfn
  *   tree should alreay be completely allocated.
  */
-void xen_build_mfn_list_list(void)
+void __refdata xen_build_mfn_list_list(void)
 {
 	unsigned long pfn;
 
-- 
1.5.6.5

[PATCH 3/3] xen p2m: annotate variable which appears unused

[Ian Campbell]

 CC      arch/x86/xen/p2m.o
arch/x86/xen/p2m.c: In function 'm2p_remove_override':
arch/x86/xen/p2m.c:460: warning: 'address' may be used uninitialized in this function
arch/x86/xen/p2m.c: In function 'm2p_add_override':
arch/x86/xen/p2m.c:426: warning: 'address' may be used uninitialized in this function

In actual fact address is inialised in one "if (!PageHighMem(page))"
statement and used in a second and so is always initialised before
use.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 arch/x86/xen/p2m.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 53fe9fc..3720efa 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -421,7 +421,7 @@ int m2p_add_override(unsigned long mfn, struct page *page)
 {
 	unsigned long flags;
 	unsigned long pfn;
-	unsigned long address;
+	unsigned long uninitialized_var(address);
 	unsigned level;
 	pte_t *ptep = NULL;
 
@@ -455,7 +455,7 @@ int m2p_remove_override(struct page *page)
 	unsigned long flags;
 	unsigned long mfn;
 	unsigned long pfn;
-	unsigned long address;
+	unsigned long uninitialized_var(address);
 	unsigned level;
 	pte_t *ptep = NULL;
 
-- 
1.5.6.5

Re: [PATCH 3/3] xen p2m: annotate variable which appears unused

[Konrad Rzeszutek Wilk]

On Fri, Feb 11, 2011 at 03:23:58PM +0000, Ian Campbell wrote:
>  CC      arch/x86/xen/p2m.o
> arch/x86/xen/p2m.c: In function 'm2p_remove_override':
> arch/x86/xen/p2m.c:460: warning: 'address' may be used uninitialized in this function
> arch/x86/xen/p2m.c: In function 'm2p_add_override':
> arch/x86/xen/p2m.c:426: warning: 'address' may be used uninitialized in this function

Thanks for  doing those. I've been seeing them for weeks now and just never
got off to fixing them.
> 
> In actual fact address is inialised in one "if (!PageHighMem(page))"
> statement and used in a second and so is always initialised before
> use.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  arch/x86/xen/p2m.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index 53fe9fc..3720efa 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -421,7 +421,7 @@ int m2p_add_override(unsigned long mfn, struct page *page)
>  {
>  	unsigned long flags;
>  	unsigned long pfn;
> -	unsigned long address;
> +	unsigned long uninitialized_var(address);
>  	unsigned level;
>  	pte_t *ptep = NULL;
>  
> @@ -455,7 +455,7 @@ int m2p_remove_override(struct page *page)
>  	unsigned long flags;
>  	unsigned long mfn;
>  	unsigned long pfn;
> -	unsigned long address;
> +	unsigned long uninitialized_var(address);
>  	unsigned level;
>  	pte_t *ptep = NULL;
>  
> -- 
> 1.5.6.5

Re: [PATCH 2/3] xen: annotate functions which only call into __init at start of day

[Jan Beulich]

>>> On 11.02.11 at 16:23, Ian Campbell <ian.campbell@citrix.com> wrote:
> Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be
> called at resume time as well as at start of day but only reference
> __init functions (extend_brk) at start of day. Hence annotate with
> __refdata.

__ref for functions (__refdata for data items).

Jan

>     WARNING: arch/x86/built-in.o(.text+0x4f1): Section mismatch in reference
>         from the function xen_hvm_init_shared_info() to the function
>         .init.text:extend_brk()
>     The function xen_hvm_init_shared_info() references
>     the function __init extend_brk().
>     This is often because xen_hvm_init_shared_info lacks a __init
>     annotation or the annotation of extend_brk is wrong.
> 
> xen_hvm_init_shared_info calls extend_brk() iff !shared_info_page and
> initialises shared_info_page with the result. This happens at start of
> day only.
> 
>     WARNING: arch/x86/built-in.o(.text+0x599b): Section mismatch in reference
>         from the function xen_build_mfn_list_list() to the function
>         .init.text:extend_brk()
>     The function xen_build_mfn_list_list() references
>     the function __init extend_brk().
>     This is often because xen_build_mfn_list_list lacks a __init
>     annotation or the annotation of extend_brk is wrong.
> 
> (this warning occurs multiple times)
> 
> xen_build_mfn_list_list only calls extend_brk() at boot time, while
> building the initial mfn list list
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>  arch/x86/xen/enlighten.c |    2 +-
>  arch/x86/xen/p2m.c       |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
> index 50542ef..f4195fa 100644
> --- a/arch/x86/xen/enlighten.c
> +++ b/arch/x86/xen/enlighten.c
> @@ -1292,7 +1292,7 @@ static int init_hvm_pv_info(int *major, int *minor)
>  	return 0;
>  }
>  
> -void xen_hvm_init_shared_info(void)
> +void __refdata xen_hvm_init_shared_info(void)
>  {
>  	int cpu;
>  	struct xen_add_to_physmap xatp;
> diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
> index fd12d7c..53fe9fc 100644
> --- a/arch/x86/xen/p2m.c
> +++ b/arch/x86/xen/p2m.c
> @@ -136,7 +136,7 @@ static void p2m_init(unsigned long *p2m)
>   * - After resume we're called from within stop_machine, but the mfn
>   *   tree should alreay be completely allocated.
>   */
> -void xen_build_mfn_list_list(void)
> +void __refdata xen_build_mfn_list_list(void)
>  {
>  	unsigned long pfn;
>  

Re: [PATCH 2/3] xen: annotate functions which only call into __init at start of day

[Ian Campbell]

On Fri, 2011-02-11 at 16:31 +0000, Jan Beulich wrote:
> >>> On 11.02.11 at 16:23, Ian Campbell <ian.campbell@citrix.com> wrote:
> > Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be
> > called at resume time as well as at start of day but only reference
> > __init functions (extend_brk) at start of day. Hence annotate with
> > __refdata.
> 
> __ref for functions (__refdata for data items).

Oops, correct. Strangely didn't generate any warnings/errors.

Ian.

>From 79f2b81934879be52353f64076b7936ba6fd08a3 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@citrix.com>
Date: Fri, 11 Feb 2011 16:36:03 +0000
Subject: [PATCH] xen: annotate functions which only call into __init at start of day

Both xen_hvm_init_shared_info and xen_build_mfn_list_list can be
called at resume time as well as at start of day but only reference
__init functions (extend_brk) at start of day. Hence annotate with
__ref.

    WARNING: arch/x86/built-in.o(.text+0x4f1): Section mismatch in reference
        from the function xen_hvm_init_shared_info() to the function
        .init.text:extend_brk()
    The function xen_hvm_init_shared_info() references
    the function __init extend_brk().
    This is often because xen_hvm_init_shared_info lacks a __init
    annotation or the annotation of extend_brk is wrong.

xen_hvm_init_shared_info calls extend_brk() iff !shared_info_page and
initialises shared_info_page with the result. This happens at start of
day only.

    WARNING: arch/x86/built-in.o(.text+0x599b): Section mismatch in reference
        from the function xen_build_mfn_list_list() to the function
        .init.text:extend_brk()
    The function xen_build_mfn_list_list() references
    the function __init extend_brk().
    This is often because xen_build_mfn_list_list lacks a __init
    annotation or the annotation of extend_brk is wrong.

(this warning occurs multiple times)

xen_build_mfn_list_list only calls extend_brk() at boot time, while
building the initial mfn list list

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 arch/x86/xen/enlighten.c |    2 +-
 arch/x86/xen/p2m.c       |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 50542ef..28e6d42 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1292,7 +1292,7 @@ static int init_hvm_pv_info(int *major, int *minor)
 	return 0;
 }
 
-void xen_hvm_init_shared_info(void)
+void __ref xen_hvm_init_shared_info(void)
 {
 	int cpu;
 	struct xen_add_to_physmap xatp;
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index fd12d7c..3239bf6 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -136,7 +136,7 @@ static void p2m_init(unsigned long *p2m)
  * - After resume we're called from within stop_machine, but the mfn
  *   tree should alreay be completely allocated.
  */
-void xen_build_mfn_list_list(void)
+void __ref xen_build_mfn_list_list(void)
 {
 	unsigned long pfn;
 
-- 
1.5.6.5