On Fri, Mar 18, 2016 at 06:40:31AM -0600, Jan Beulich wrote:
> >>> On 15.03.16 at 18:56, <konrad.w...@oracle.com> wrote:
> > --- a/xen/include/asm-arm/bug.h
> > +++ b/xen/include/asm-arm/bug.h
> > @@ -31,6 +31,7 @@ struct bug_frame {
> > #define BUGFRAME_warn 0
> > #define BUGFRAME_bug 1
> > #define BUGFRAME_assert 2
> > +#define BUGFRAME_NR 3
> >
> > /* Many versions of GCC doesn't support the asm %c parameter which would
> > * be preferable to this unpleasantness. We use mergeable string
> > @@ -39,6 +40,7 @@ struct bug_frame {
> > */
> > #define BUG_FRAME(type, line, file, has_msg, msg) do {
> > \
> > BUILD_BUG_ON((line) >> 16);
> > \
> > + BUILD_BUG_ON(type >= BUGFRAME_NR);
> > \
>
> The x86 variant has type properly parenthesized - why not here?
>
> > --- a/xen/include/asm-x86/bug.h
> > +++ b/xen/include/asm-x86/bug.h
> > @@ -9,7 +9,7 @@
> > #define BUGFRAME_warn 1
> > #define BUGFRAME_bug 2
> > #define BUGFRAME_assert 3
> > -
> > +#define BUGFRAME_NR 4
> > #ifndef __ASSEMBLY__
>
> Please retain the blank line.
>
> > @@ -51,6 +51,7 @@ struct bug_frame {
> >
> > #define BUG_FRAME(type, line, ptr, second_frame, msg) do {
> > \
> > BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH + BUG_LINE_HI_WIDTH));
> > \
> > + BUILD_BUG_ON((type) >= (BUGFRAME_NR));
> > \
>
> The ARM variant has BUGFRAME_NR properly un-parenthesized -
> why here?
I know I copied and pasted it and I must have done something uncanny.
Anyhow this is what the change looks like now (I've retained the Reviewed
and Ack as I think this change is mostly cosmetical in nature?)
From 123ad665b283f8c59688bd86be0bbe79ce5723bb Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Date: Thu, 10 Mar 2016 16:45:31 -0500
Subject: [PATCH] x86/arm: Add BUGFRAME_NR define and BUILD checks.
So that we have a nice mechansim to figure out the upper
bounds of bug.frames and also catch compiler errors in case
one tries to use a higher frame number.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
Acked-by: Julien Grall <julien.gr...@arm.com>
---
Cc: Stefano Stabellini <stefano.stabell...@citrix.com>
Cc: Julien Grall <julien.gr...@arm.com>
Cc: Keir Fraser <k...@xen.org>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Andrew Cooper <andrew.coop...@citrix.com>
v3: First time included.
v4: Add BUG_FRAME check also in the assembler version of the macro.
v5: Add Acks, make BUILD_BUG_ON checks look correct. Position the
BUGFRAME_NR properly.
---
---
xen/include/asm-arm/bug.h | 3 +++
xen/include/asm-x86/bug.h | 7 +++++++
2 files changed, 10 insertions(+)
diff --git a/xen/include/asm-arm/bug.h b/xen/include/asm-arm/bug.h
index ab9e811..68353e1 100644
--- a/xen/include/asm-arm/bug.h
+++ b/xen/include/asm-arm/bug.h
@@ -32,6 +32,8 @@ struct bug_frame {
#define BUGFRAME_bug 1
#define BUGFRAME_assert 2
+#define BUGFRAME_NR 3
+
/* Many versions of GCC doesn't support the asm %c parameter which would
* be preferable to this unpleasantness. We use mergeable string
* sections to avoid multiple copies of the string appearing in the
@@ -39,6 +41,7 @@ struct bug_frame {
*/
#define BUG_FRAME(type, line, file, has_msg, msg) do { \
BUILD_BUG_ON((line) >> 16); \
+ BUILD_BUG_ON((type) >= BUGFRAME_NR); \
asm ("1:"BUG_INSTR"\n" \
".pushsection .rodata.str, \"aMS\", %progbits, 1\n" \
"2:\t.asciz " __stringify(file) "\n" \
diff --git a/xen/include/asm-x86/bug.h b/xen/include/asm-x86/bug.h
index e868e85..7825565 100644
--- a/xen/include/asm-x86/bug.h
+++ b/xen/include/asm-x86/bug.h
@@ -10,6 +10,7 @@
#define BUGFRAME_bug 2
#define BUGFRAME_assert 3
+#define BUGFRAME_NR 4
#ifndef __ASSEMBLY__
struct bug_frame {
@@ -51,6 +52,7 @@ struct bug_frame {
#define BUG_FRAME(type, line, ptr, second_frame, msg) do { \
BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH + BUG_LINE_HI_WIDTH)); \
+ BUILD_BUG_ON((type) >= BUGFRAME_NR); \
asm volatile ( _ASM_BUGFRAME_TEXT(second_frame) \
:: _ASM_BUGFRAME_INFO(type, line, ptr, msg) ); \
} while (0)
@@ -83,6 +85,11 @@ extern const struct bug_frame __start_bug_frames[],
* in .rodata
*/
.macro BUG_FRAME type, line, file_str, second_frame, msg
+
+ .if \type >= BUGFRAME_NR
+ .error "Invalid BUGFRAME index"
+ .endif
+
.L\@ud: ud2a
.pushsection .rodata.str1, "aMS", @progbits, 1
--
2.5.0
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