Re: [PATCH v1 3/4] xen/x86: switch x86 to use generic implemetation of bug.h

[Oleksii]

On Mon, 2023-02-13 at 14:10 +0100, Jan Beulich wrote:
> On 03.02.2023 18:05, Oleksii Kurochko wrote:
> > Signed-off-by: Oleksii Kurochko 
> 
> Is there anything keeping x86 from also using the generic
> do_bug_frame()?
> If not, switching over would then likely mean no need for the new
> Kconfig
> control.
> 
Actually, it seems that it is possible to re-use bug_frame in x86 code
too. Looking at lines 1188 - 1264 [1]
they are mostly the same [2] except for updating of eip [3], processing
of BUGFRAME_bug - was added debugger_trap_fatal [4] and multiple usages
of fixup_exception_return() [5]. But all this stuff can be processed
outside do_bug_frame() function...

[1]
https://gitlab.com/xen-project/people/olkur/xen/-/blob/staging/xen/arch/x86/traps.c#L1188
[2]
https://gitlab.com/xen-project/people/olkur/xen/-/blob/generic-bug-h/xen/common/bug.c#L10
[3]https://gitlab.com/xen-project/people/olkur/xen/-/blob/staging/xen/arch/x86/traps.c#L1211
[4]
https://gitlab.com/xen-project/people/olkur/xen/-/blob/staging/xen/arch/x86/traps.c#L1244
[5]
https://gitlab.com/xen-project/people/olkur/xen/-/blob/staging/xen/arch/x86/traps.c#L1217
> Jan

Re: [PATCH v1 3/4] xen/x86: switch x86 to use generic implemetation of bug.h

[Jan Beulich]

On 03.02.2023 18:05, Oleksii Kurochko wrote:
> Signed-off-by: Oleksii Kurochko 

Is there anything keeping x86 from also using the generic do_bug_frame()?
If not, switching over would then likely mean no need for the new Kconfig
control.

Jan

[PATCH v1 3/4] xen/x86: switch x86 to use generic implemetation of bug.h

[Oleksii Kurochko]

Signed-off-by: Oleksii Kurochko 
---
 xen/arch/x86/acpi/cpufreq/cpufreq.c  |  2 +-
 xen/arch/x86/include/asm/asm_defns.h |  2 +-
 xen/arch/x86/include/asm/bug.h   | 32 ++--
 3 files changed, 4 insertions(+), 32 deletions(-)

diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c 
b/xen/arch/x86/acpi/cpufreq/cpufreq.c
index c27cbb2304..18ff2a443b 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -27,6 +27,7 @@
  * ~~
  */
 
+#include 
 #include 
 #include 
 #include 
@@ -35,7 +36,6 @@
 #include 
 #include 
 #include 
-#include 
 #include 
 #include 
 #include 
diff --git a/xen/arch/x86/include/asm/asm_defns.h 
b/xen/arch/x86/include/asm/asm_defns.h
index d9431180cf..a8526cf36c 100644
--- a/xen/arch/x86/include/asm/asm_defns.h
+++ b/xen/arch/x86/include/asm/asm_defns.h
@@ -6,7 +6,7 @@
 /* NB. Auto-generated from arch/.../asm-offsets.c */
 #include 
 #endif
-#include 
+#include 
 #include 
 #include 
 #include 
diff --git a/xen/arch/x86/include/asm/bug.h b/xen/arch/x86/include/asm/bug.h
index b7265bdfbe..6ead21d9fe 100644
--- a/xen/arch/x86/include/asm/bug.h
+++ b/xen/arch/x86/include/asm/bug.h
@@ -1,19 +1,10 @@
 #ifndef __X86_BUG_H__
 #define __X86_BUG_H__
 
-#define BUG_DISP_WIDTH24
-#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
-#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
-
-#define BUGFRAME_run_fn 0
-#define BUGFRAME_warn   1
-#define BUGFRAME_bug2
-#define BUGFRAME_assert 3
-
-#define BUGFRAME_NR 4
-
 #ifndef __ASSEMBLY__
 
+#define BUG_FRAME_STUFF
+
 struct bug_frame {
 signed int loc_disp:BUG_DISP_WIDTH;
 unsigned int line_hi:BUG_LINE_HI_WIDTH;
@@ -58,13 +49,6 @@ struct bug_frame {
:: _ASM_BUGFRAME_INFO(type, line, ptr, msg) );\
 } while (0)
 
-
-#define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 0, NULL)
-#define BUG() do {  \
-BUG_FRAME(BUGFRAME_bug,  __LINE__, __FILE__, 0, NULL);  \
-unreachable();  \
-} while (0)
-
 /*
  * TODO: untangle header dependences, break BUILD_BUG_ON() out of xen/lib.h,
  * and use a real static inline here to get proper type checking of fn().
@@ -75,19 +59,7 @@ struct bug_frame {
 BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL); \
 } while ( 0 )
 
-#define assert_failed(msg) do { \
-BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \
-unreachable();  \
-} while (0)
-
-extern const struct bug_frame __start_bug_frames[],
-  __stop_bug_frames_0[],
-  __stop_bug_frames_1[],
-  __stop_bug_frames_2[],
-  __stop_bug_frames_3[];
-
 #else  /* !__ASSEMBLY__ */
-
 /*
  * Construct a bugframe, suitable for using in assembly code.  Should always
  * match the C version above.  One complication is having to stash the strings
-- 
2.39.0