* [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h
@ 2023-03-07 15:50 Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME Oleksii Kurochko
` (3 more replies)
0 siblings, 4 replies; 12+ messages in thread
From: Oleksii Kurochko @ 2023-03-07 15:50 UTC (permalink / raw
To: xen-devel
Cc: Julien Grall, Jan Beulich, Andrew Cooper, Stefano Stabellini,
Gianluca Guida, Oleksii Kurochko, George Dunlap, Wei Liu,
Bertrand Marquis, Volodymyr Babchuk, Roger Pau Monné
A large part of the content of the bug.h is repeated among all
architectures (especially x86 and RISCV have the same implementation), so it
was created a new config CONFIG_GENERIC_BUG_FRAME which is used to
introduce generic implementation of do_bug_frame() and move x86's <asm/bug.h>
to <xen/common/...> with the following changes:
* Add inclusion of arch-specific header <asm/bug.h>
* Rename the guard and remove x86 specific changes
* Wrap macros BUG_FRAME/run_in_exception_handler/WARN/BUG/assert_failed/etc
into #ifndef "BUG_FRAME/run_in_exception_handler/WARN/BUG/assert_failed/etc"
thereby each architecture can override the generic implementation of macros.
* Add #if{n}def __ASSEMBLY__ ... #endif
* Introduce BUG_FRAME_STRUCTURE define to be able to change the structure of bug
frame
* Introduce BUG_INSTR and BUG_ASM_CONST to make _ASM_BUGFRAME_TEXT reusable between
architectures
* Introduce BUG_DEBUGGER_TRAP_FATAL to hide details about TRAP_invalid_op for specific
architecture
* Introduce BUILD_BUG_ON_LINE_WIDTH(line) to make more generic BUG_FRAME macros
* Make macros related to bug frame structure more generic.
RISC-V will be switched to use <xen/bug.h> and in the future, it will use common
the version of do_bug_frame() when xen/common will work for RISC-V.
---
Changes in V6:
* Update the cover letter message: add information that BUG_DEBUGGER_TRAP_FATAL() and
BUILD_BUG_ON_LINE_WIDTH().
* Introduce BUILD_BUG_ON_LINE_WIDTH(line) to make more generic BUG_FRAME macros.
* fix addressed code style
* change -EINVAL to -ENOENT in case when bug_frame wasn't found in generic do_bug_frame().
* change all 'return id' to 'break' inside switch/case of do_bug_frame().
* move up "#ifndef __ASSEMBLY__" to include BUG_DEBUGGER_TRAP_FATAL.
* update the comment of BUG_ASM_CONST.
* Introduce BUILD_BUG_ON_LINE_WIDTH(line) to make more generic BUG_FRAME macros
* remove #ifndef BUG_FRAME_STRUCT around BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH as it is
required to be defined before <asm/bug.h> as it is used by x86's <asm/bug.h> when
the header is included in assembly code.
* add undef of BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH for ARM & x86
as they were introduced unconditionally in <xen/bug.h>.
* update the type of eip to 'void *' in do_invalid_op() for x86
* fix the logic of do_invalid_op() for x86
* move macros BUG_DEBUGGER_TRAP_FATAL under #ifndef __ASSEMBLY__ as
it is not necessary to be in assembly code for x86.
---
Changes in V5:
* Update the cover letter message as the patch, on which the patch series
is based, has been merged to staging.
* Remove "#ifdef BUG_FN_REG..." from generic do_bug_frame() as ARM will
use generic implementation fully.
---
Changes in V4:
* Introduce and use generic BUG_DEBUGGER_TRAP_FATAL(regs) mnacros which is used to deal with
debugger_trap_fatal(TRAP_invalid_op, regs) where TRAP_invalid_op is x86-specific.
* Add comment what do_bug_frame() returns.
* Do refactoring of do_bug_frame():
* invert the condition 'if ( region )' in do_bug_frame() to reduce the indention.
* change type of variable i from 'unsigned int' to 'size_t' as it is compared with
n_bugs which has type 'size_t'
* Remove '#include <xen/stringify.h>' from <xen/bug.h> as it doesn't need any more after switch to
x86 implementation.
* Remove '#include <xen/errno.h>' as it isn't needed any more
* Move bug_*() macros inside '#ifndef BUG_FRAME_STRUCT'
* Add <xen/lib.h> to fix compile issue with BUILD_ON()...
* Add documentation for BUG_ASM_CONST.
* Defines BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH, BUG_LINE_HI_WIDTH were moved into
"ifndef BUG_FRAME_STRUCT" in <xen/bug.h> as they are specific for 'struct bug_frame' and so should
co-exist together. So the defines were back to <asm/bug.h> until BUG_FRAME_STRUCT will be defined in
<asm/bug.h>.
* Switch ARM implementation to generic one
* Remove BUG_FN_REG from arm{16,32}/bug.h as it isn't needed after switch to generic implementation
* Back comment /* !__ASSEMBLY__ */ for #else case in <asm/bug.h>
* Remove changes related to x86/.../asm/debuger.h as do_bug_frame() prototype was updated and cpu_user_regs
isn't const any more.
---
Changes in V3:
* Nothing was done with the comment in <xen/bug.h> before run_in_exception_handler
but I think it can be changed during the merge.
* Add debugger_trap_fatal() to do_bug_frame(). It simplifies usage of
do_bug_frame() for x86 so making handle_bug_frame() and find_bug_frame()
not needed anymore.
* Update do_bug_frame() to return -EINVAL if something goes wrong; otherwise
id of bug_frame
* Update _ASM_BUGFRAME_TEXT to make it more portable.
* Drop unnecessary comments.
* Update patch 2 not to break compilation: move some parts from patches 3 and 4
to patch 2
* As prototype and what do_bug_frame() returns was changed so patch 3 and 4
was updated to use a new version of do_bug_frame
* Change debugger_trap_fatal() prototype for x86 to align with prototype in
<xen/debugger.h>
---
Changes in V2:
* Update cover letter.
* Switch to x86 implementation as generic as it is more compact ( at least from the point of view of bug frame structure).
* Put [PATCH v1 4/4] xen: change <asm/bug.h> to <xen/bug.h> as second patch,
update the patch to change all <asm/bug.h> to <xen/bug.h> among the whole project
to not break compilation.
* Rename CONFIG_GENERIC_DO_BUG_FRAME to CONFIG_GENERIC_BUG_FRAME.
* Change the macro bug_loc(b) to avoid the need for a cast:
#define bug_loc(b) ((unsigned long)(b) + (b)->loc_disp)
* Rename BUG_FRAME_STUFF to BUG_FRAME_STRUCT
* Make macros related to bug frame structure more generic.
* Rename bug_file() in ARM implementation to bug_ptr() as generic do_bug_frame() uses
bug_ptr().
* Introduce BUG_INSTR and MODIFIER to make _ASM_BUGFRAME_TEXT reusable between x86 and
RISC-V.
* Rework do_invalid_op() in x86 ( re-use handle_bug_frame() and find_bug_frame() )
---
Oleksii Kurochko (4):
xen: introduce CONFIG_GENERIC_BUG_FRAME
xen: change <asm/bug.h> to <xen/bug.h>
xen/arm: switch ARM to use generic implementation of bug.h
xen/x86: switch x86 to use generic implemetation of bug.h
xen/arch/arm/Kconfig | 1 +
xen/arch/arm/arm32/traps.c | 2 +-
xen/arch/arm/include/asm/arm32/bug.h | 2 -
xen/arch/arm/include/asm/arm64/bug.h | 2 -
xen/arch/arm/include/asm/bug.h | 88 +--------------
xen/arch/arm/include/asm/div64.h | 2 +-
xen/arch/arm/include/asm/traps.h | 2 -
xen/arch/arm/traps.c | 81 +-------------
xen/arch/arm/vgic/vgic-v2.c | 2 +-
xen/arch/arm/vgic/vgic.c | 2 +-
xen/arch/x86/Kconfig | 1 +
xen/arch/x86/acpi/cpufreq/cpufreq.c | 2 +-
xen/arch/x86/include/asm/asm_defns.h | 2 +-
xen/arch/x86/include/asm/bug.h | 84 +-------------
xen/arch/x86/traps.c | 81 ++------------
xen/common/Kconfig | 3 +
xen/common/Makefile | 1 +
xen/common/bug.c | 104 ++++++++++++++++++
xen/drivers/cpufreq/cpufreq.c | 2 +-
xen/include/xen/bug.h | 158 +++++++++++++++++++++++++++
xen/include/xen/lib.h | 2 +-
21 files changed, 291 insertions(+), 333 deletions(-)
create mode 100644 xen/common/bug.c
create mode 100644 xen/include/xen/bug.h
--
2.39.0
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME
2023-03-07 15:50 [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h Oleksii Kurochko
@ 2023-03-07 15:50 ` Oleksii Kurochko
2023-03-08 15:06 ` Jan Beulich
2023-03-07 15:50 ` [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h> Oleksii Kurochko
` (2 subsequent siblings)
3 siblings, 1 reply; 12+ messages in thread
From: Oleksii Kurochko @ 2023-03-07 15:50 UTC (permalink / raw
To: xen-devel
Cc: Julien Grall, Jan Beulich, Andrew Cooper, Stefano Stabellini,
Gianluca Guida, Oleksii Kurochko, George Dunlap, Wei Liu
A large part of the content of the bug.h is repeated among all
architectures, so it was decided to create a new config
CONFIG_GENERIC_BUG_FRAME.
The version of <bug.h> from x86 was taken as the base version.
The patch introduces the following stuff:
* common bug.h header
* generic implementation of do_bug_frame
* new config CONFIG_GENERIC_BUG_FRAME
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V6:
* fix code style.
* change -EINVAL to -ENOENT in case when bug_frame wasn't found in
generic do_bug_frame()
* change all 'return id' to 'break' inside switch/case of generic do_bug_frame()
* move up "#ifndef __ASSEMBLY__" to include BUG_DEBUGGER_TRAP_FATAL
* update the comment of BUG_ASM_CONST
* make the line with 'BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH + BUG_LINE_HI_WIDTH))' in
BUG_FRAME macros more abstract
* remove #ifndef BUG_FRAME_STRUCT around BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH as it is
required to be defined before <asm/bug.h> as it is used by x86's <asm/bug.h> when
the header is included in assembly code.
---
Changes in V5:
* Remove "#ifdef BUG_FN_REG..." from generic do_bug_frame() as ARM will
use generic implementation fully.
---
Changes in V4:
* common/bug.c:
- Use BUG_DEBUGGER_TRAP_FATAL(regs) mnacros instead of debugger_trap_fatal(TRAP_invalid_op, regs)
in <common/bug.c> as TRAP_invalid_op is x86-specific thereby BUG_DEBUGGER_TRAP_FATAL should
be defined for each architecture.
- add information about what do_bug_frame() returns.
- invert the condition 'if ( region )' in do_bug_frame() to reduce the indention.
- change type of variable i from 'unsigned int' to 'size_t' as it is compared with
n_bugs which has type 'size_t'
* xen/bug.h:
- Introduce generic BUG_DEBUGGER_TRAP_FATAL(regs) mnacros which is used to deal with
debugger_trap_fatal(TRAP_invalid_op, regs) where TRAP_invalid_op is x86-specific
- remove '#include <xen/stringify.h>' as it doesn't need any more after switch to
x86 implementation.
- remove '#include <xen/errno.h>' as it isn't needed any more
- move bug_*() macros inside '#ifndef BUG_FRAME_STRUCT'
- add <xen/lib.h> to fix compile issue with BUILD_ON()...
- Add documentation for BUG_ASM_CONST.
* Update the commit message
---
Changes in V3:
* Add debugger_trap_fatal() to do_bug_frame(). It simplifies usage of
do_bug_frame() for x86 so making handle_bug_frame() and find_bug_frame()
not needed anymore.
* Update do_bug_frame() to return -EINVAL if something goes wrong; otherwise
id of bug_frame
* Update _ASM_BUGFRAME_TEXT to make it more portable.
* Drop unnecessary comments.
* define stub value for TRAP_invalid_op in case if wasn't defined in
arch-specific folders.
---
Changes in V2:
- Switch to x86 implementation as generic as it is more compact
( at least from the point of view of bug frame structure ).
- Rename CONFIG_GENERIC_DO_BUG_FRAME to CONFIG_GENERIC_BUG_FRAME.
- Change the macro bug_loc(b) to avoid the need for a cast:
#define bug_loc(b) ((unsigned long)(b) + (b)->loc_disp)
- Rename BUG_FRAME_STUFF to BUG_FRAME_STRUCT
- Make macros related to bug frame structure more generic.
- Introduce BUG_INSTR and MODIFIER to make _ASM_BUGFRAME_TEXT reusable
between x86 and RISC-V.
- Rework do_bug_frame() and introduce find_bug_frame() and handle_bug_frame()
functions to make it reusable by x86.
- code style fixes
---
xen/common/Kconfig | 3 +
xen/common/Makefile | 1 +
xen/common/bug.c | 104 +++++++++++++++++++++++++++
xen/include/xen/bug.h | 158 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 266 insertions(+)
create mode 100644 xen/common/bug.c
create mode 100644 xen/include/xen/bug.h
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index f1ea3199c8..b226323537 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -28,6 +28,9 @@ config ALTERNATIVE_CALL
config ARCH_MAP_DOMAIN_PAGE
bool
+config GENERIC_BUG_FRAME
+ bool
+
config HAS_ALTERNATIVE
bool
diff --git a/xen/common/Makefile b/xen/common/Makefile
index bbd75b4be6..46049eac35 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_ARGO) += argo.o
obj-y += bitmap.o
+obj-$(CONFIG_GENERIC_BUG_FRAME) += bug.o
obj-$(CONFIG_HYPFS_CONFIG) += config_data.o
obj-$(CONFIG_CORE_PARKING) += core_parking.o
obj-y += cpu.o
diff --git a/xen/common/bug.c b/xen/common/bug.c
new file mode 100644
index 0000000000..be8f3b783d
--- /dev/null
+++ b/xen/common/bug.c
@@ -0,0 +1,104 @@
+#include <xen/bug.h>
+#include <xen/debugger.h>
+#include <xen/errno.h>
+#include <xen/kernel.h>
+#include <xen/livepatch.h>
+#include <xen/string.h>
+#include <xen/types.h>
+#include <xen/virtual_region.h>
+
+#include <asm/processor.h>
+
+/*
+ * Returns a negative value in case of an error otherwise
+ * BUGFRAME_{run_fn, warn, bug, assert}
+ */
+int do_bug_frame(struct cpu_user_regs *regs, unsigned long pc)
+{
+ const struct bug_frame *bug = NULL;
+ const struct virtual_region *region;
+ const char *prefix = "", *filename, *predicate;
+ unsigned long fixup;
+ unsigned int id = BUGFRAME_NR, lineno;
+
+ region = find_text_region(pc);
+ if ( !region )
+ return -EINVAL;
+
+ for ( id = 0; id < BUGFRAME_NR; id++ )
+ {
+ const struct bug_frame *b;
+ size_t i;
+
+ for ( i = 0, b = region->frame[id].bugs;
+ i < region->frame[id].n_bugs; b++, i++ )
+ {
+ if ( bug_loc(b) == pc )
+ {
+ bug = b;
+ goto found;
+ }
+ }
+ }
+
+ found:
+ if ( !bug )
+ return -ENOENT;
+
+ if ( id == BUGFRAME_run_fn )
+ {
+ void (*fn)(const struct cpu_user_regs *) = bug_ptr(bug);
+
+ fn(regs);
+
+ return id;
+ }
+
+ /* WARN, BUG or ASSERT: decode the filename pointer and line number. */
+ filename = bug_ptr(bug);
+ if ( !is_kernel(filename) && !is_patch(filename) )
+ return -EINVAL;
+ fixup = strlen(filename);
+ if ( fixup > 50 )
+ {
+ filename += fixup - 47;
+ prefix = "...";
+ }
+ lineno = bug_line(bug);
+
+ switch ( id )
+ {
+ case BUGFRAME_warn:
+ printk("Xen WARN at %s%s:%d\n", prefix, filename, lineno);
+ show_execution_state(regs);
+
+ break;
+
+ case BUGFRAME_bug:
+ printk("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
+
+ if ( BUG_DEBUGGER_TRAP_FATAL(regs) )
+ break;
+
+ show_execution_state(regs);
+ panic("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
+
+ case BUGFRAME_assert:
+ /* ASSERT: decode the predicate string pointer. */
+ predicate = bug_msg(bug);
+ if ( !is_kernel(predicate) && !is_patch(predicate) )
+ predicate = "<unknown>";
+
+ printk("Assertion '%s' failed at %s%s:%d\n",
+ predicate, prefix, filename, lineno);
+
+ if ( BUG_DEBUGGER_TRAP_FATAL(regs) )
+ break;
+
+ show_execution_state(regs);
+ panic("Assertion '%s' failed at %s%s:%d\n",
+ predicate, prefix, filename, lineno);
+ }
+
+ return id;
+}
diff --git a/xen/include/xen/bug.h b/xen/include/xen/bug.h
new file mode 100644
index 0000000000..de793f324d
--- /dev/null
+++ b/xen/include/xen/bug.h
@@ -0,0 +1,158 @@
+#ifndef __XEN_BUG_H__
+#define __XEN_BUG_H__
+
+#define BUGFRAME_run_fn 0
+#define BUGFRAME_warn 1
+#define BUGFRAME_bug 2
+#define BUGFRAME_assert 3
+
+#define BUGFRAME_NR 4
+
+#define BUG_DISP_WIDTH 24
+#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
+#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
+
+#include <asm/bug.h>
+
+#ifndef __ASSEMBLY__
+
+#ifndef BUG_DEBUGGER_TRAP_FATAL
+#define BUG_DEBUGGER_TRAP_FATAL(regs) 0
+#endif
+
+#include <xen/lib.h>
+
+#ifndef BUG_FRAME_STRUCT
+
+struct bug_frame {
+ signed int loc_disp:BUG_DISP_WIDTH;
+ unsigned int line_hi:BUG_LINE_HI_WIDTH;
+ signed int ptr_disp:BUG_DISP_WIDTH;
+ unsigned int line_lo:BUG_LINE_LO_WIDTH;
+ signed int msg_disp[];
+};
+
+#define bug_loc(b) ((unsigned long)(b) + (b)->loc_disp)
+
+#define bug_ptr(b) ((const void *)(b) + (b)->ptr_disp)
+
+#define bug_line(b) (((((b)->line_hi + ((b)->loc_disp < 0)) & \
+ ((1 << BUG_LINE_HI_WIDTH) - 1)) << \
+ BUG_LINE_LO_WIDTH) + \
+ (((b)->line_lo + ((b)->ptr_disp < 0)) & \
+ ((1 << BUG_LINE_LO_WIDTH) - 1)))
+
+#define bug_msg(b) ((const char *)(b) + (b)->msg_disp[1])
+
+#endif /* BUG_FRAME_STRUCT */
+
+/*
+ * Some architectures mark immediate instruction operands in a special way.
+ * In such cases the special marking may need omitting when specifying
+ * directive operands. Allow architectures to specify a suitable
+ * modifier.
+ */
+#ifndef BUG_ASM_CONST
+#define BUG_ASM_CONST ""
+#endif
+
+#ifndef _ASM_BUGFRAME_TEXT
+
+#define _ASM_BUGFRAME_TEXT(second_frame) \
+ ".Lbug%=:"BUG_INSTR"\n" \
+ " .pushsection .bug_frames.%"BUG_ASM_CONST"[bf_type], \"a\", %%progbits\n" \
+ " .p2align 2\n" \
+ ".Lfrm%=:\n" \
+ " .long (.Lbug%= - .Lfrm%=) + %"BUG_ASM_CONST"[bf_line_hi]\n" \
+ " .long (%"BUG_ASM_CONST"[bf_ptr] - .Lfrm%=) + %"BUG_ASM_CONST"[bf_line_lo]\n"\
+ " .if " #second_frame "\n" \
+ " .long 0, %"BUG_ASM_CONST"[bf_msg] - .Lfrm%=\n" \
+ " .endif\n" \
+ " .popsection\n"
+
+#define _ASM_BUGFRAME_INFO(type, line, ptr, msg) \
+ [bf_type] "i" (type), \
+ [bf_ptr] "i" (ptr), \
+ [bf_msg] "i" (msg), \
+ [bf_line_lo] "i" ((line & ((1 << BUG_LINE_LO_WIDTH) - 1)) \
+ << BUG_DISP_WIDTH), \
+ [bf_line_hi] "i" (((line) >> BUG_LINE_LO_WIDTH) << BUG_DISP_WIDTH)
+
+#endif /* _ASM_BUGFRAME_TEXT */
+
+#ifndef BUILD_BUG_ON_LINE_WIDTH
+#define BUILD_BUG_ON_LINE_WIDTH(line) \
+ BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH + BUG_LINE_HI_WIDTH))
+#endif
+
+#ifndef BUG_FRAME
+
+#define BUG_FRAME(type, line, ptr, second_frame, msg) do { \
+ BUILD_BUG_ON_LINE_WIDTH(line); \
+ BUILD_BUG_ON((type) >= BUGFRAME_NR); \
+ asm volatile ( _ASM_BUGFRAME_TEXT(second_frame) \
+ :: _ASM_BUGFRAME_INFO(type, line, ptr, msg) ); \
+} while (false)
+
+#endif
+
+#ifndef run_in_exception_handler
+
+/*
+ * 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().
+ */
+#define run_in_exception_handler(fn) do { \
+ (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
+ BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL); \
+} while ( false )
+
+#endif /* run_in_exception_handler */
+
+#ifndef WARN
+#define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 0, NULL)
+#endif
+
+#ifndef BUG
+#define BUG() do { \
+ BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 0, NULL); \
+ unreachable(); \
+} while (false)
+#endif
+
+#ifndef assert_failed
+#define assert_failed(msg) do { \
+ BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \
+ unreachable(); \
+} while (false)
+#endif
+
+#ifdef CONFIG_GENERIC_BUG_FRAME
+
+struct cpu_user_regs;
+
+/*
+ * Returns a negative value in case of an error otherwise
+ * BUGFRAME_{run_fn, warn, bug, assert}
+ */
+int do_bug_frame(struct cpu_user_regs *regs, unsigned long pc);
+
+#endif /* CONFIG_GENERIC_BUG_FRAME */
+
+extern const struct bug_frame __start_bug_frames[],
+ __stop_bug_frames_0[],
+ __stop_bug_frames_1[],
+ __stop_bug_frames_2[],
+ __stop_bug_frames_3[];
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __XEN_BUG_H__ */
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--
2.39.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h>
2023-03-07 15:50 [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME Oleksii Kurochko
@ 2023-03-07 15:50 ` Oleksii Kurochko
2023-03-08 15:27 ` Jan Beulich
2023-03-07 15:50 ` [PATCH v6 3/4] xen/arm: switch ARM to use generic implementation of bug.h Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation " Oleksii Kurochko
3 siblings, 1 reply; 12+ messages in thread
From: Oleksii Kurochko @ 2023-03-07 15:50 UTC (permalink / raw
To: xen-devel
Cc: Julien Grall, Jan Beulich, Andrew Cooper, Stefano Stabellini,
Gianluca Guida, Oleksii Kurochko, Bertrand Marquis,
Volodymyr Babchuk, George Dunlap, Wei Liu, Roger Pau Monné
The idea of the patch is to change all <asm/bug.h> to <xen/bug.h> and
keep Xen compilable with adding only minimal amount of changes:
1. It was added "#include <xen/types.h>" to ARM's "<asm/bug.h>" as it
uses uint_{16,32}t in 'struct bug_frame'.
2. It was added '#define BUG_FRAME_STRUCT' which means that ARM hasn't
been switched to generic implementation yet.
3. It was added '#define BUG_FRAME_STRUCT' which means that x86 hasn't
been switched to generic implementation yet.
4. BUGFRAME_* and _start_bug_frame[], _stop_bug_frame_*[] were removed
for ARM & x86 to deal with compilation errors such as:
redundant redeclaration of ...
5. It was added undef of BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH
for ARM & x86 as they were introduced unconditionally in <xen/bug.h>.
The macros should be defined before <asm/bug.h> in <xen/bug.h> as x86's
<asm/bug.h> implementation requires them in case when the header is
included in assembly code.
The macros will be deleted in the following patches where
the architectures will be switched fully to generic implementation.
In the following two patches x86 and ARM archictectures will be
switched fully:
* xen/arm: switch ARM to use generic implementation of bug.h
* xen/x86: switch x86 to use generic implemetation of bug.h
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V6:
- change the inclusion order of <xen/bug.h>.
- add #undef of BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH for ARM & x86
as they were introduced unconditionally in <xen/bug.h>.
- update the commit message
---
Changes in V5:
- Nothing changed
---
Changes in V4:
- defines BUG_DISP_WIDTH, BUG_LINE_LO_WIDTH, BUG_LINE_HI_WIDTH were moved into
"ifndef BUG_FRAME_STRUCT" in <xen/bug.h> as they are specific for 'struct bug_frame' and so should
co-exist together. So the defines were back to <asm/bug.h> until BUG_FRAME_STRUCT will be defined in
<asm/bug.h>.
- Update the comment message.
---
Changes in V3:
* Update patch 2 not to break compilation: move some parts from patches 3 and 4
to patch 2:
* move some generic parts from <asm/bug.h> to <xen/bug.h>
* add define BUG_FRAME_STRUCT in ARM's <asm/bug.h>
---
Changes in V2:
* Put [PATCH v1 4/4] xen: change <asm/bug.h> to <xen/bug.h> as second patch,
update the patch to change all <asm/bug.h> to <xen/bug.h> among the whole project
to not break build.
* Update the commit message.
---
xen/arch/arm/include/asm/bug.h | 21 ++++++++-------------
xen/arch/arm/include/asm/div64.h | 2 +-
xen/arch/arm/vgic/vgic-v2.c | 2 +-
xen/arch/arm/vgic/vgic.c | 2 +-
xen/arch/x86/acpi/cpufreq/cpufreq.c | 2 +-
xen/arch/x86/include/asm/asm_defns.h | 2 +-
xen/arch/x86/include/asm/bug.h | 19 ++++++-------------
xen/drivers/cpufreq/cpufreq.c | 2 +-
xen/include/xen/lib.h | 2 +-
9 files changed, 21 insertions(+), 33 deletions(-)
diff --git a/xen/arch/arm/include/asm/bug.h b/xen/arch/arm/include/asm/bug.h
index f4088d0913..9ed9412fa8 100644
--- a/xen/arch/arm/include/asm/bug.h
+++ b/xen/arch/arm/include/asm/bug.h
@@ -1,6 +1,8 @@
#ifndef __ARM_BUG_H__
#define __ARM_BUG_H__
+#include <xen/types.h>
+
#if defined(CONFIG_ARM_32)
# include <asm/arm32/bug.h>
#elif defined(CONFIG_ARM_64)
@@ -9,10 +11,16 @@
# error "unknown ARM variant"
#endif
+#undef BUG_DISP_WIDTH
+#undef BUG_LINE_LO_WIDTH
+#undef BUG_LINE_HI_WIDTH
+
#define BUG_DISP_WIDTH 24
#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
+#define BUG_FRAME_STRUCT
+
struct bug_frame {
signed int loc_disp; /* Relative address to the bug address */
signed int file_disp; /* Relative address to the filename */
@@ -26,13 +34,6 @@ struct bug_frame {
#define bug_line(b) ((b)->line)
#define bug_msg(b) ((const char *)(b) + (b)->msg_disp)
-#define BUGFRAME_run_fn 0
-#define BUGFRAME_warn 1
-#define BUGFRAME_bug 2
-#define BUGFRAME_assert 3
-
-#define BUGFRAME_NR 4
-
/* 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
@@ -89,12 +90,6 @@ struct bug_frame {
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[];
-
#endif /* __ARM_BUG_H__ */
/*
* Local variables:
diff --git a/xen/arch/arm/include/asm/div64.h b/xen/arch/arm/include/asm/div64.h
index 1cd58bc51a..fc667a80f9 100644
--- a/xen/arch/arm/include/asm/div64.h
+++ b/xen/arch/arm/include/asm/div64.h
@@ -74,7 +74,7 @@
#elif __GNUC__ >= 4
-#include <asm/bug.h>
+#include <xen/bug.h>
/*
* If the divisor happens to be constant, we determine the appropriate
diff --git a/xen/arch/arm/vgic/vgic-v2.c b/xen/arch/arm/vgic/vgic-v2.c
index 1a99d3a8b4..c90e88fddb 100644
--- a/xen/arch/arm/vgic/vgic-v2.c
+++ b/xen/arch/arm/vgic/vgic-v2.c
@@ -16,8 +16,8 @@
*/
#include <asm/new_vgic.h>
-#include <asm/bug.h>
#include <asm/gic.h>
+#include <xen/bug.h>
#include <xen/sched.h>
#include <xen/sizes.h>
diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index f0f2ea5021..b9463a5f27 100644
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -15,9 +15,9 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <xen/bug.h>
#include <xen/list_sort.h>
#include <xen/sched.h>
-#include <asm/bug.h>
#include <asm/event.h>
#include <asm/new_vgic.h>
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 <xen/bug.h>
#include <xen/types.h>
#include <xen/errno.h>
#include <xen/delay.h>
@@ -35,7 +36,6 @@
#include <xen/sched.h>
#include <xen/timer.h>
#include <xen/xmalloc.h>
-#include <asm/bug.h>
#include <asm/msr.h>
#include <asm/io.h>
#include <asm/processor.h>
diff --git a/xen/arch/x86/include/asm/asm_defns.h b/xen/arch/x86/include/asm/asm_defns.h
index d9431180cf..baaaccb26e 100644
--- a/xen/arch/x86/include/asm/asm_defns.h
+++ b/xen/arch/x86/include/asm/asm_defns.h
@@ -6,8 +6,8 @@
/* NB. Auto-generated from arch/.../asm-offsets.c */
#include <asm/asm-offsets.h>
#endif
-#include <asm/bug.h>
#include <asm/x86-defns.h>
+#include <xen/bug.h>
#include <xen/stringify.h>
#include <asm/cpufeature.h>
#include <asm/alternative.h>
diff --git a/xen/arch/x86/include/asm/bug.h b/xen/arch/x86/include/asm/bug.h
index b7265bdfbe..ff5cca1f19 100644
--- a/xen/arch/x86/include/asm/bug.h
+++ b/xen/arch/x86/include/asm/bug.h
@@ -1,19 +1,18 @@
#ifndef __X86_BUG_H__
#define __X86_BUG_H__
+#undef BUG_DISP_WIDTH
+#undef BUG_LINE_LO_WIDTH
+#undef BUG_LINE_HI_WIDTH
+
#define BUG_DISP_WIDTH 24
#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_bug 2
-#define BUGFRAME_assert 3
-
-#define BUGFRAME_NR 4
-
#ifndef __ASSEMBLY__
+#define BUG_FRAME_STRUCT
+
struct bug_frame {
signed int loc_disp:BUG_DISP_WIDTH;
unsigned int line_hi:BUG_LINE_HI_WIDTH;
@@ -80,12 +79,6 @@ struct bug_frame {
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__ */
/*
diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index a94520ee57..354f78580b 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -26,6 +26,7 @@
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
+#include <xen/bug.h>
#include <xen/types.h>
#include <xen/errno.h>
#include <xen/delay.h>
@@ -39,7 +40,6 @@
#include <xen/guest_access.h>
#include <xen/domain.h>
#include <xen/cpu.h>
-#include <asm/bug.h>
#include <asm/io.h>
#include <asm/processor.h>
diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h
index 05ee1e18af..e914ccade0 100644
--- a/xen/include/xen/lib.h
+++ b/xen/include/xen/lib.h
@@ -24,12 +24,12 @@
#ifndef __ASSEMBLY__
+#include <xen/bug.h>
#include <xen/inttypes.h>
#include <xen/stdarg.h>
#include <xen/types.h>
#include <xen/xmalloc.h>
#include <xen/string.h>
-#include <asm/bug.h>
#define BUG_ON(p) do { if (unlikely(p)) BUG(); } while (0)
#define WARN_ON(p) ({ \
--
2.39.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v6 3/4] xen/arm: switch ARM to use generic implementation of bug.h
2023-03-07 15:50 [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h> Oleksii Kurochko
@ 2023-03-07 15:50 ` Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation " Oleksii Kurochko
3 siblings, 0 replies; 12+ messages in thread
From: Oleksii Kurochko @ 2023-03-07 15:50 UTC (permalink / raw
To: xen-devel
Cc: Julien Grall, Jan Beulich, Andrew Cooper, Stefano Stabellini,
Gianluca Guida, Oleksii Kurochko, Bertrand Marquis,
Volodymyr Babchuk
The following changes were made:
* make GENERIC_BUG_FRAME mandatory for ARM
* As do_bug_frame() returns -EINVAL in case something goes wrong
otherwise id of bug frame. Thereby 'if' cases where do_bug_frame() was
updated to check if the returned value is less than 0
* Switch ARM's implementation of bug.h macros to generic one
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V6:
* Update the "changes in v5"
* Rebase on top of the patch [xen: introduce CONFIG_GENERIC_BUG_FRAME] as
there were minor changes.
---
Changes in V5:
* common/bug.c changes were removed after rebase
(the patch [xen: introduce CONFIG_GENERIC_BUG_FRAME] was reworked to make
ARM implementation to use generic do_bug_frame())
---
Changes in V4:
* Switch ARM implementation to generic one
* Remove BUG_FN_REG from arm{16,32}/bug.h as it isn't needed after switch to generic implementation
* Update commit message
---
Changes in V3:
* As prototype and what do_bug_frame() returns was changed so patch 3 and 4
was updated to use a new version of do_bug_frame
---
Changes in V2:
* Rename bug_file() in ARM implementation to bug_ptr() as
generic do_bug_frame() uses bug_ptr().
* Remove generic parts from bug.h
* Remove declaration of 'int do_bug_frame(...)'
from <asm/traps.h> as it was introduced in <xen/bug.h>
---
xen/arch/arm/Kconfig | 1 +
xen/arch/arm/arm32/traps.c | 2 +-
xen/arch/arm/include/asm/arm32/bug.h | 2 -
xen/arch/arm/include/asm/arm64/bug.h | 2 -
xen/arch/arm/include/asm/bug.h | 79 +--------------------------
xen/arch/arm/include/asm/traps.h | 2 -
xen/arch/arm/traps.c | 81 +---------------------------
7 files changed, 4 insertions(+), 165 deletions(-)
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index 239d3aed3c..aad6644a7b 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -12,6 +12,7 @@ config ARM_64
config ARM
def_bool y
+ select GENERIC_BUG_FRAME
select HAS_ALTERNATIVE
select HAS_DEVICE_TREE
select HAS_PASSTHROUGH
diff --git a/xen/arch/arm/arm32/traps.c b/xen/arch/arm/arm32/traps.c
index a2fc1c22cb..61c61132c7 100644
--- a/xen/arch/arm/arm32/traps.c
+++ b/xen/arch/arm/arm32/traps.c
@@ -48,7 +48,7 @@ void do_trap_undefined_instruction(struct cpu_user_regs *regs)
if ( instr != BUG_OPCODE )
goto die;
- if ( do_bug_frame(regs, pc) )
+ if ( do_bug_frame(regs, pc) < 0 )
goto die;
regs->pc += 4;
diff --git a/xen/arch/arm/include/asm/arm32/bug.h b/xen/arch/arm/include/asm/arm32/bug.h
index 25cce151dc..3e66f35969 100644
--- a/xen/arch/arm/include/asm/arm32/bug.h
+++ b/xen/arch/arm/include/asm/arm32/bug.h
@@ -10,6 +10,4 @@
#define BUG_INSTR ".word " __stringify(BUG_OPCODE)
-#define BUG_FN_REG r0
-
#endif /* __ARM_ARM32_BUG_H__ */
diff --git a/xen/arch/arm/include/asm/arm64/bug.h b/xen/arch/arm/include/asm/arm64/bug.h
index 5e11c0dfd5..59f664d7de 100644
--- a/xen/arch/arm/include/asm/arm64/bug.h
+++ b/xen/arch/arm/include/asm/arm64/bug.h
@@ -6,6 +6,4 @@
#define BUG_INSTR "brk " __stringify(BRK_BUG_FRAME_IMM)
-#define BUG_FN_REG x0
-
#endif /* __ARM_ARM64_BUG_H__ */
diff --git a/xen/arch/arm/include/asm/bug.h b/xen/arch/arm/include/asm/bug.h
index 9ed9412fa8..1d87533044 100644
--- a/xen/arch/arm/include/asm/bug.h
+++ b/xen/arch/arm/include/asm/bug.h
@@ -11,84 +11,7 @@
# error "unknown ARM variant"
#endif
-#undef BUG_DISP_WIDTH
-#undef BUG_LINE_LO_WIDTH
-#undef BUG_LINE_HI_WIDTH
-
-#define BUG_DISP_WIDTH 24
-#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
-#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
-
-#define BUG_FRAME_STRUCT
-
-struct bug_frame {
- signed int loc_disp; /* Relative address to the bug address */
- signed int file_disp; /* Relative address to the filename */
- signed int msg_disp; /* Relative address to the predicate (for ASSERT) */
- uint16_t line; /* Line number */
- uint32_t pad0:16; /* Padding for 8-bytes align */
-};
-
-#define bug_loc(b) ((const void *)(b) + (b)->loc_disp)
-#define bug_file(b) ((const void *)(b) + (b)->file_disp);
-#define bug_line(b) ((b)->line)
-#define bug_msg(b) ((const char *)(b) + (b)->msg_disp)
-
-/* 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
- * Xen image. BUGFRAME_run_fn needs to be handled separately.
- */
-#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" \
- "3:\n" \
- ".if " #has_msg "\n" \
- "\t.asciz " #msg "\n" \
- ".endif\n" \
- ".popsection\n" \
- ".pushsection .bug_frames." __stringify(type) ", \"a\", %progbits\n"\
- "4:\n" \
- ".p2align 2\n" \
- ".long (1b - 4b)\n" \
- ".long (2b - 4b)\n" \
- ".long (3b - 4b)\n" \
- ".hword " __stringify(line) ", 0\n" \
- ".popsection"); \
-} while (0)
-
-/*
- * GCC will not allow to use "i" when PIE is enabled (Xen doesn't set the
- * flag but instead rely on the default value from the compiler). So the
- * easiest way to implement run_in_exception_handler() is to pass the to
- * be called function in a fixed register.
- */
-#define run_in_exception_handler(fn) do { \
- asm ("mov " __stringify(BUG_FN_REG) ", %0\n" \
- "1:"BUG_INSTR"\n" \
- ".pushsection .bug_frames." __stringify(BUGFRAME_run_fn) "," \
- " \"a\", %%progbits\n" \
- "2:\n" \
- ".p2align 2\n" \
- ".long (1b - 2b)\n" \
- ".long 0, 0, 0\n" \
- ".popsection" :: "r" (fn) : __stringify(BUG_FN_REG) ); \
-} while (0)
-
-#define WARN() BUG_FRAME(BUGFRAME_warn, __LINE__, __FILE__, 0, "")
-
-#define BUG() do { \
- BUG_FRAME(BUGFRAME_bug, __LINE__, __FILE__, 0, ""); \
- unreachable(); \
-} while (0)
-
-#define assert_failed(msg) do { \
- BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \
- unreachable(); \
-} while (0)
+#define BUG_ASM_CONST "c"
#endif /* __ARM_BUG_H__ */
/*
diff --git a/xen/arch/arm/include/asm/traps.h b/xen/arch/arm/include/asm/traps.h
index 883dae368e..c6518008ec 100644
--- a/xen/arch/arm/include/asm/traps.h
+++ b/xen/arch/arm/include/asm/traps.h
@@ -69,8 +69,6 @@ void do_cp(struct cpu_user_regs *regs, const union hsr hsr);
void do_trap_smc(struct cpu_user_regs *regs, const union hsr hsr);
void do_trap_hvc_smccc(struct cpu_user_regs *regs);
-int do_bug_frame(const struct cpu_user_regs *regs, vaddr_t pc);
-
void noreturn do_unexpected_trap(const char *msg,
const struct cpu_user_regs *regs);
void do_trap_hyp_sync(struct cpu_user_regs *regs);
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 061c92acbd..9c6eb66422 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1197,85 +1197,6 @@ void do_unexpected_trap(const char *msg, const struct cpu_user_regs *regs)
panic("CPU%d: Unexpected Trap: %s\n", smp_processor_id(), msg);
}
-int do_bug_frame(const struct cpu_user_regs *regs, vaddr_t pc)
-{
- const struct bug_frame *bug = NULL;
- const char *prefix = "", *filename, *predicate;
- unsigned long fixup;
- int id = -1, lineno;
- const struct virtual_region *region;
-
- region = find_text_region(pc);
- if ( region )
- {
- for ( id = 0; id < BUGFRAME_NR; id++ )
- {
- const struct bug_frame *b;
- unsigned int i;
-
- for ( i = 0, b = region->frame[id].bugs;
- i < region->frame[id].n_bugs; b++, i++ )
- {
- if ( ((vaddr_t)bug_loc(b)) == pc )
- {
- bug = b;
- goto found;
- }
- }
- }
- }
- found:
- if ( !bug )
- return -ENOENT;
-
- if ( id == BUGFRAME_run_fn )
- {
- void (*fn)(const struct cpu_user_regs *) = (void *)regs->BUG_FN_REG;
-
- fn(regs);
- return 0;
- }
-
- /* WARN, BUG or ASSERT: decode the filename pointer and line number. */
- filename = bug_file(bug);
- if ( !is_kernel(filename) )
- return -EINVAL;
- fixup = strlen(filename);
- if ( fixup > 50 )
- {
- filename += fixup - 47;
- prefix = "...";
- }
- lineno = bug_line(bug);
-
- switch ( id )
- {
- case BUGFRAME_warn:
- printk("Xen WARN at %s%s:%d\n", prefix, filename, lineno);
- show_execution_state(regs);
- return 0;
-
- case BUGFRAME_bug:
- printk("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
- show_execution_state(regs);
- panic("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
-
- case BUGFRAME_assert:
- /* ASSERT: decode the predicate string pointer. */
- predicate = bug_msg(bug);
- if ( !is_kernel(predicate) )
- predicate = "<unknown>";
-
- printk("Assertion '%s' failed at %s%s:%d\n",
- predicate, prefix, filename, lineno);
- show_execution_state(regs);
- panic("Assertion '%s' failed at %s%s:%d\n",
- predicate, prefix, filename, lineno);
- }
-
- return -EINVAL;
-}
-
#ifdef CONFIG_ARM_64
static void do_trap_brk(struct cpu_user_regs *regs, const union hsr hsr)
{
@@ -1292,7 +1213,7 @@ static void do_trap_brk(struct cpu_user_regs *regs, const union hsr hsr)
switch ( hsr.brk.comment )
{
case BRK_BUG_FRAME_IMM:
- if ( do_bug_frame(regs, regs->pc) )
+ if ( do_bug_frame(regs, regs->pc) < 0 )
goto die;
regs->pc += 4;
--
2.39.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation of bug.h
2023-03-07 15:50 [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h Oleksii Kurochko
` (2 preceding siblings ...)
2023-03-07 15:50 ` [PATCH v6 3/4] xen/arm: switch ARM to use generic implementation of bug.h Oleksii Kurochko
@ 2023-03-07 15:50 ` Oleksii Kurochko
2023-03-08 15:33 ` Jan Beulich
3 siblings, 1 reply; 12+ messages in thread
From: Oleksii Kurochko @ 2023-03-07 15:50 UTC (permalink / raw
To: xen-devel
Cc: Julien Grall, Jan Beulich, Andrew Cooper, Stefano Stabellini,
Gianluca Guida, Oleksii Kurochko, Roger Pau Monné, Wei Liu
The following changes were made:
* Make GENERIC_BUG_FRAME mandatory for X86
* Update asm/bug.h using generic implementation in <xen/bug.h>
* Update do_invalid_op using generic do_bug_frame()
* Define BUG_DEBUGGER_TRAP_FATAL to debugger_trap_fatal(X86_EXC_GP,regs)
* type of eip variable was changed to 'void *'
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
---
Changes in V6:
* update the commit message
* update the type of eip to 'void *' in do_invalid_op()
* fix the logic of do_invalid_op()
* move macros BUG_DEBUGGER_TRAP_FATAL under #ifndef __ASSEMBLY__ as
it is not necessary to be in assembly code.
---
Changes in V5:
* Nothing changed
---
Changes in V4:
* Back comment /* !__ASSEMBLY__ */ for #else case in <asm/bug.h>
* Remove changes related to x86/.../asm/debuger.h as do_bug_frame() prototype
was updated and cpu_user_regs isn't const any more.
---
Changes in V3:
* As prototype and what do_bug_frame() returns was changed so patch 3 and 4
was updated to use a new version of do_bug_frame
* MODIFIER was change to BUG_ASM_CONST to align with generic implementation
---
Changes in V2:
* Remove all unnecessary things from <asm/bug.h> as they were introduced in
<xen/bug.h>.
* Define BUG_INSTR = 'ud2' and MODIFIER = 'c' ( it is needed to skip '$'
when use an imidiate in x86 assembly )
* Update do_invalid_op() to re-use handle_bug_frame() and find_bug_frame()
from generic implemetation of CONFIG_GENERIC_BUG_FRAME
* Code style fixes.
---
xen/arch/x86/Kconfig | 1 +
xen/arch/x86/include/asm/bug.h | 77 ++------------------------------
xen/arch/x86/traps.c | 81 ++++------------------------------
3 files changed, 12 insertions(+), 147 deletions(-)
diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index 6a7825f4ba..b0ff1f3ee6 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -11,6 +11,7 @@ config X86
select ARCH_MAP_DOMAIN_PAGE
select ARCH_SUPPORTS_INT128
select CORE_PARKING
+ select GENERIC_BUG_FRAME
select HAS_ALTERNATIVE
select HAS_COMPAT
select HAS_CPUFREQ
diff --git a/xen/arch/x86/include/asm/bug.h b/xen/arch/x86/include/asm/bug.h
index ff5cca1f19..f852cd0ee9 100644
--- a/xen/arch/x86/include/asm/bug.h
+++ b/xen/arch/x86/include/asm/bug.h
@@ -1,83 +1,12 @@
#ifndef __X86_BUG_H__
#define __X86_BUG_H__
-#undef BUG_DISP_WIDTH
-#undef BUG_LINE_LO_WIDTH
-#undef BUG_LINE_HI_WIDTH
-
-#define BUG_DISP_WIDTH 24
-#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
-#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
-
#ifndef __ASSEMBLY__
-#define BUG_FRAME_STRUCT
-
-struct bug_frame {
- signed int loc_disp:BUG_DISP_WIDTH;
- unsigned int line_hi:BUG_LINE_HI_WIDTH;
- signed int ptr_disp:BUG_DISP_WIDTH;
- unsigned int line_lo:BUG_LINE_LO_WIDTH;
- signed int msg_disp[];
-};
-
-#define bug_loc(b) ((const void *)(b) + (b)->loc_disp)
-#define bug_ptr(b) ((const void *)(b) + (b)->ptr_disp)
-#define bug_line(b) (((((b)->line_hi + ((b)->loc_disp < 0)) & \
- ((1 << BUG_LINE_HI_WIDTH) - 1)) << \
- BUG_LINE_LO_WIDTH) + \
- (((b)->line_lo + ((b)->ptr_disp < 0)) & \
- ((1 << BUG_LINE_LO_WIDTH) - 1)))
-#define bug_msg(b) ((const char *)(b) + (b)->msg_disp[1])
-
-#define _ASM_BUGFRAME_TEXT(second_frame) \
- ".Lbug%=: ud2\n" \
- ".pushsection .bug_frames.%c[bf_type], \"a\", @progbits\n" \
- ".p2align 2\n" \
- ".Lfrm%=:\n" \
- ".long (.Lbug%= - .Lfrm%=) + %c[bf_line_hi]\n" \
- ".long (%c[bf_ptr] - .Lfrm%=) + %c[bf_line_lo]\n" \
- ".if " #second_frame "\n" \
- ".long 0, %c[bf_msg] - .Lfrm%=\n" \
- ".endif\n" \
- ".popsection\n" \
-
-#define _ASM_BUGFRAME_INFO(type, line, ptr, msg) \
- [bf_type] "i" (type), \
- [bf_ptr] "i" (ptr), \
- [bf_msg] "i" (msg), \
- [bf_line_lo] "i" ((line & ((1 << BUG_LINE_LO_WIDTH) - 1)) \
- << BUG_DISP_WIDTH), \
- [bf_line_hi] "i" (((line) >> BUG_LINE_LO_WIDTH) << BUG_DISP_WIDTH)
-
-#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)
-
-
-#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().
- */
-#define run_in_exception_handler(fn) \
- do { \
- (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
- BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL); \
- } while ( 0 )
+#define BUG_DEBUGGER_TRAP_FATAL(regs) debugger_trap_fatal(X86_EXC_GP,regs)
-#define assert_failed(msg) do { \
- BUG_FRAME(BUGFRAME_assert, __LINE__, __FILE__, 1, msg); \
- unreachable(); \
-} while (0)
+#define BUG_INSTR "ud2"
+#define BUG_ASM_CONST "c"
#else /* !__ASSEMBLY__ */
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index cade9e12f8..3ee256f469 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -24,6 +24,7 @@
* Gareth Hughes <gareth@valinux.com>, May 2000
*/
+#include <xen/bug.h>
#include <xen/init.h>
#include <xen/sched.h>
#include <xen/lib.h>
@@ -1166,12 +1167,9 @@ void cpuid_hypervisor_leaves(const struct vcpu *v, uint32_t leaf,
void do_invalid_op(struct cpu_user_regs *regs)
{
- const struct bug_frame *bug = NULL;
u8 bug_insn[2];
- const char *prefix = "", *filename, *predicate, *eip = (char *)regs->rip;
- unsigned long fixup;
- int id = -1, lineno;
- const struct virtual_region *region;
+ void *eip = (void *)regs->rip;
+ int id;
if ( likely(guest_mode(regs)) )
{
@@ -1185,83 +1183,20 @@ void do_invalid_op(struct cpu_user_regs *regs)
memcmp(bug_insn, "\xf\xb", sizeof(bug_insn)) )
goto die;
- region = find_text_region(regs->rip);
- if ( region )
- {
- for ( id = 0; id < BUGFRAME_NR; id++ )
- {
- const struct bug_frame *b;
- unsigned int i;
-
- for ( i = 0, b = region->frame[id].bugs;
- i < region->frame[id].n_bugs; b++, i++ )
- {
- if ( bug_loc(b) == eip )
- {
- bug = b;
- goto found;
- }
- }
- }
- }
-
- found:
- if ( !bug )
+ id = do_bug_frame(regs, regs->rip);
+ if ( id < 0 )
goto die;
- eip += sizeof(bug_insn);
- if ( id == BUGFRAME_run_fn )
- {
- void (*fn)(struct cpu_user_regs *) = bug_ptr(bug);
-
- fn(regs);
- fixup_exception_return(regs, (unsigned long)eip);
- return;
- }
- /* WARN, BUG or ASSERT: decode the filename pointer and line number. */
- filename = bug_ptr(bug);
- if ( !is_kernel(filename) && !is_patch(filename) )
- goto die;
- fixup = strlen(filename);
- if ( fixup > 50 )
- {
- filename += fixup - 47;
- prefix = "...";
- }
- lineno = bug_line(bug);
+ eip = (unsigned char *)eip + sizeof(bug_insn);
switch ( id )
{
+ case BUGFRAME_run_fn:
case BUGFRAME_warn:
- printk("Xen WARN at %s%s:%d\n", prefix, filename, lineno);
- show_execution_state(regs);
fixup_exception_return(regs, (unsigned long)eip);
- return;
-
case BUGFRAME_bug:
- printk("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
-
- if ( debugger_trap_fatal(TRAP_invalid_op, regs) )
- return;
-
- show_execution_state(regs);
- panic("Xen BUG at %s%s:%d\n", prefix, filename, lineno);
-
case BUGFRAME_assert:
- /* ASSERT: decode the predicate string pointer. */
- predicate = bug_msg(bug);
- if ( !is_kernel(predicate) && !is_patch(predicate) )
- predicate = "<unknown>";
-
- printk("Assertion '%s' failed at %s%s:%d\n",
- predicate, prefix, filename, lineno);
-
- if ( debugger_trap_fatal(TRAP_invalid_op, regs) )
- return;
-
- show_execution_state(regs);
- panic("Assertion '%s' failed at %s%s:%d\n",
- predicate, prefix, filename, lineno);
+ return;
}
die:
--
2.39.0
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME
2023-03-07 15:50 ` [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME Oleksii Kurochko
@ 2023-03-08 15:06 ` Jan Beulich
2023-03-08 17:18 ` Oleksii
0 siblings, 1 reply; 12+ messages in thread
From: Jan Beulich @ 2023-03-08 15:06 UTC (permalink / raw
To: Oleksii Kurochko
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
George Dunlap, Wei Liu, xen-devel
On 07.03.2023 16:50, Oleksii Kurochko wrote:
> --- /dev/null
> +++ b/xen/common/bug.c
> @@ -0,0 +1,104 @@
> +#include <xen/bug.h>
> +#include <xen/debugger.h>
Isn't it asm/bug.h now which is to include this header, if needed at all?
> --- /dev/null
> +++ b/xen/include/xen/bug.h
> @@ -0,0 +1,158 @@
> +#ifndef __XEN_BUG_H__
> +#define __XEN_BUG_H__
> +
> +#define BUGFRAME_run_fn 0
> +#define BUGFRAME_warn 1
> +#define BUGFRAME_bug 2
> +#define BUGFRAME_assert 3
> +
> +#define BUGFRAME_NR 4
> +
> +#define BUG_DISP_WIDTH 24
> +#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> +#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
> +
> +#include <asm/bug.h>
> +
> +#ifndef __ASSEMBLY__
> +
> +#ifndef BUG_DEBUGGER_TRAP_FATAL
> +#define BUG_DEBUGGER_TRAP_FATAL(regs) 0
> +#endif
> +
> +#include <xen/lib.h>
> +
> +#ifndef BUG_FRAME_STRUCT
> +
> +struct bug_frame {
> + signed int loc_disp:BUG_DISP_WIDTH;
> + unsigned int line_hi:BUG_LINE_HI_WIDTH;
> + signed int ptr_disp:BUG_DISP_WIDTH;
> + unsigned int line_lo:BUG_LINE_LO_WIDTH;
> + signed int msg_disp[];
> +};
> +
> +#define bug_loc(b) ((unsigned long)(b) + (b)->loc_disp)
> +
> +#define bug_ptr(b) ((const void *)(b) + (b)->ptr_disp)
> +
> +#define bug_line(b) (((((b)->line_hi + ((b)->loc_disp < 0)) & \
> + ((1 << BUG_LINE_HI_WIDTH) - 1)) << \
> + BUG_LINE_LO_WIDTH) + \
> + (((b)->line_lo + ((b)->ptr_disp < 0)) & \
> + ((1 << BUG_LINE_LO_WIDTH) - 1)))
> +
> +#define bug_msg(b) ((const char *)(b) + (b)->msg_disp[1])
As indicated earlier, I think that you want to move here what you
currently have ...
> +#endif /* BUG_FRAME_STRUCT */
> +
> +/*
> + * Some architectures mark immediate instruction operands in a special way.
> + * In such cases the special marking may need omitting when specifying
> + * directive operands. Allow architectures to specify a suitable
> + * modifier.
> + */
> +#ifndef BUG_ASM_CONST
> +#define BUG_ASM_CONST ""
> +#endif
> +
> +#ifndef _ASM_BUGFRAME_TEXT
> +
> +#define _ASM_BUGFRAME_TEXT(second_frame) \
> + ".Lbug%=:"BUG_INSTR"\n" \
> + " .pushsection .bug_frames.%"BUG_ASM_CONST"[bf_type], \"a\", %%progbits\n" \
> + " .p2align 2\n" \
> + ".Lfrm%=:\n" \
> + " .long (.Lbug%= - .Lfrm%=) + %"BUG_ASM_CONST"[bf_line_hi]\n" \
> + " .long (%"BUG_ASM_CONST"[bf_ptr] - .Lfrm%=) + %"BUG_ASM_CONST"[bf_line_lo]\n"\
> + " .if " #second_frame "\n" \
> + " .long 0, %"BUG_ASM_CONST"[bf_msg] - .Lfrm%=\n" \
> + " .endif\n" \
> + " .popsection\n"
> +
> +#define _ASM_BUGFRAME_INFO(type, line, ptr, msg) \
> + [bf_type] "i" (type), \
> + [bf_ptr] "i" (ptr), \
> + [bf_msg] "i" (msg), \
> + [bf_line_lo] "i" ((line & ((1 << BUG_LINE_LO_WIDTH) - 1)) \
> + << BUG_DISP_WIDTH), \
> + [bf_line_hi] "i" (((line) >> BUG_LINE_LO_WIDTH) << BUG_DISP_WIDTH)
> +
> +#endif /* _ASM_BUGFRAME_TEXT */
> +
> +#ifndef BUILD_BUG_ON_LINE_WIDTH
> +#define BUILD_BUG_ON_LINE_WIDTH(line) \
> + BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH + BUG_LINE_HI_WIDTH))
> +#endif
... here, guarded by a separate #ifdef. The check is specifically tied to
the struct layout chosen here. Instead what you want here is
#ifndef BUILD_BUG_ON_LINE_WIDTH
#define BUILD_BUG_ON_LINE_WIDTH(line) ((void)(line))
#endif
covering architectures using a different layout where such a check isn't
needed. Of course this also could move up and simply become "#elif ..."
to the earlier "#if !defined(BUG_FRAME_STRUCT)", which would keep
related things together.
> +#ifndef BUG_FRAME
> +
> +#define BUG_FRAME(type, line, ptr, second_frame, msg) do { \
> + BUILD_BUG_ON_LINE_WIDTH(line); \
> + BUILD_BUG_ON((type) >= BUGFRAME_NR); \
> + asm volatile ( _ASM_BUGFRAME_TEXT(second_frame) \
> + :: _ASM_BUGFRAME_INFO(type, line, ptr, msg) ); \
> +} while (false)
Nit: Style.
> +
> +#endif
> +
> +#ifndef run_in_exception_handler
> +
> +/*
> + * 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().
> + */
> +#define run_in_exception_handler(fn) do { \
> + (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
Hmm, there's another const-ness anomaly that has slipped in (and is
no longer necessary with do_bug_frame() now again taking a pointer to
non-const): At the point you handle BUGFRAME_run_fn the type used
(wrongly) is void (*)(const struct cpu_user_regs *).
The disconnect isn't good to leave (as the same issue could be
introduced later, when not looking closely enough). While not for
this patch, I wonder if we shouldn't make the use site be something
along the lines of
if ( id == BUGFRAME_run_fn )
{
void (*fn)(struct cpu_user_regs *) = bug_ptr(bug);
fn(regs);
/* Re-enforce consistent types, because of the casts involved. */
if ( false )
run_in_exception_handler(fn);
return id;
}
just to make sure the type used in run_in_exception_handler()
matches the one used here (without actually producing any code).
Jan
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h>
2023-03-07 15:50 ` [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h> Oleksii Kurochko
@ 2023-03-08 15:27 ` Jan Beulich
2023-03-08 17:25 ` Oleksii
0 siblings, 1 reply; 12+ messages in thread
From: Jan Beulich @ 2023-03-08 15:27 UTC (permalink / raw
To: Oleksii Kurochko
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
Bertrand Marquis, Volodymyr Babchuk, George Dunlap, Wei Liu,
Roger Pau Monné, xen-devel
On 07.03.2023 16:50, Oleksii Kurochko wrote:
> --- a/xen/arch/arm/include/asm/bug.h
> +++ b/xen/arch/arm/include/asm/bug.h
> @@ -1,6 +1,8 @@
> #ifndef __ARM_BUG_H__
> #define __ARM_BUG_H__
>
> +#include <xen/types.h>
> +
> #if defined(CONFIG_ARM_32)
> # include <asm/arm32/bug.h>
> #elif defined(CONFIG_ARM_64)
> @@ -9,10 +11,16 @@
> # error "unknown ARM variant"
> #endif
>
> +#undef BUG_DISP_WIDTH
> +#undef BUG_LINE_LO_WIDTH
> +#undef BUG_LINE_HI_WIDTH
Why? For Arm ...
> #define BUG_DISP_WIDTH 24
> #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
... you could purge these as unused, even in a standalone prereq patch.
And on x86 ...
> --- a/xen/arch/x86/include/asm/bug.h
> +++ b/xen/arch/x86/include/asm/bug.h
> @@ -1,19 +1,18 @@
> #ifndef __X86_BUG_H__
> #define __X86_BUG_H__
>
> +#undef BUG_DISP_WIDTH
> +#undef BUG_LINE_LO_WIDTH
> +#undef BUG_LINE_HI_WIDTH
> +
> #define BUG_DISP_WIDTH 24
> #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
... there's no reason to #undef just to the #define again to the same
values. All of this would be removed in a subsequent patch anyway, and
it's less code churn (with code nevertheless being correct) if you get
rid of the #define-s right away (as iirc you had it in an earlier
version). If you agree then with these adjustments
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Jan
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation of bug.h
2023-03-07 15:50 ` [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation " Oleksii Kurochko
@ 2023-03-08 15:33 ` Jan Beulich
2023-03-08 17:48 ` Oleksii
0 siblings, 1 reply; 12+ messages in thread
From: Jan Beulich @ 2023-03-08 15:33 UTC (permalink / raw
To: Oleksii Kurochko
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
Roger Pau Monné, Wei Liu, xen-devel
On 07.03.2023 16:50, Oleksii Kurochko wrote:
> @@ -1166,12 +1167,9 @@ void cpuid_hypervisor_leaves(const struct vcpu *v, uint32_t leaf,
>
> void do_invalid_op(struct cpu_user_regs *regs)
> {
> - const struct bug_frame *bug = NULL;
> u8 bug_insn[2];
> - const char *prefix = "", *filename, *predicate, *eip = (char *)regs->rip;
> - unsigned long fixup;
> - int id = -1, lineno;
> - const struct virtual_region *region;
> + void *eip = (void *)regs->rip;
As said elsewhere already: "const" please whenever possible. The more that
the variable was pointer-to-const before.
> @@ -1185,83 +1183,20 @@ void do_invalid_op(struct cpu_user_regs *regs)
> memcmp(bug_insn, "\xf\xb", sizeof(bug_insn)) )
> goto die;
>
> - region = find_text_region(regs->rip);
> - if ( region )
> - {
> - for ( id = 0; id < BUGFRAME_NR; id++ )
> - {
> - const struct bug_frame *b;
> - unsigned int i;
> -
> - for ( i = 0, b = region->frame[id].bugs;
> - i < region->frame[id].n_bugs; b++, i++ )
> - {
> - if ( bug_loc(b) == eip )
> - {
> - bug = b;
> - goto found;
> - }
> - }
> - }
> - }
> -
> - found:
> - if ( !bug )
> + id = do_bug_frame(regs, regs->rip);
> + if ( id < 0 )
> goto die;
> - eip += sizeof(bug_insn);
> - if ( id == BUGFRAME_run_fn )
> - {
> - void (*fn)(struct cpu_user_regs *) = bug_ptr(bug);
> -
> - fn(regs);
> - fixup_exception_return(regs, (unsigned long)eip);
> - return;
> - }
>
> - /* WARN, BUG or ASSERT: decode the filename pointer and line number. */
> - filename = bug_ptr(bug);
> - if ( !is_kernel(filename) && !is_patch(filename) )
> - goto die;
> - fixup = strlen(filename);
> - if ( fixup > 50 )
> - {
> - filename += fixup - 47;
> - prefix = "...";
> - }
> - lineno = bug_line(bug);
> + eip = (unsigned char *)eip + sizeof(bug_insn);
Why don't you keep the original
eip += sizeof(bug_insn);
? As also said before we use the GNU extension of arithmetic on pointers
to void pretty extensively elsewhere; there's no reason at all to
introduce an unnecessary and questionable cast here.
With these adjustments and with the re-basing over the changes requested
to patch 2
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Jan
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME
2023-03-08 15:06 ` Jan Beulich
@ 2023-03-08 17:18 ` Oleksii
0 siblings, 0 replies; 12+ messages in thread
From: Oleksii @ 2023-03-08 17:18 UTC (permalink / raw
To: Jan Beulich
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
George Dunlap, Wei Liu, xen-devel
On Wed, 2023-03-08 at 16:06 +0100, Jan Beulich wrote:
> On 07.03.2023 16:50, Oleksii Kurochko wrote:
> > --- /dev/null
> > +++ b/xen/common/bug.c
> > @@ -0,0 +1,104 @@
> > +#include <xen/bug.h>
> > +#include <xen/debugger.h>
>
> Isn't it asm/bug.h now which is to include this header, if needed at
> all?
You are right it will be better to move <xen/debugger.h> to
<asm/bug.h>.
>
> > --- /dev/null
> > +++ b/xen/include/xen/bug.h
> > @@ -0,0 +1,158 @@
> > +#ifndef __XEN_BUG_H__
> > +#define __XEN_BUG_H__
> > +
> > +#define BUGFRAME_run_fn 0
> > +#define BUGFRAME_warn 1
> > +#define BUGFRAME_bug 2
> > +#define BUGFRAME_assert 3
> > +
> > +#define BUGFRAME_NR 4
> > +
> > +#define BUG_DISP_WIDTH 24
> > +#define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> > +#define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
> > +
> > +#include <asm/bug.h>
> > +
> > +#ifndef __ASSEMBLY__
> > +
> > +#ifndef BUG_DEBUGGER_TRAP_FATAL
> > +#define BUG_DEBUGGER_TRAP_FATAL(regs) 0
> > +#endif
> > +
> > +#include <xen/lib.h>
> > +
> > +#ifndef BUG_FRAME_STRUCT
> > +
> > +struct bug_frame {
> > + signed int loc_disp:BUG_DISP_WIDTH;
> > + unsigned int line_hi:BUG_LINE_HI_WIDTH;
> > + signed int ptr_disp:BUG_DISP_WIDTH;
> > + unsigned int line_lo:BUG_LINE_LO_WIDTH;
> > + signed int msg_disp[];
> > +};
> > +
> > +#define bug_loc(b) ((unsigned long)(b) + (b)->loc_disp)
> > +
> > +#define bug_ptr(b) ((const void *)(b) + (b)->ptr_disp)
> > +
> > +#define bug_line(b) (((((b)->line_hi + ((b)->loc_disp < 0))
> > & \
> > + ((1 << BUG_LINE_HI_WIDTH) - 1))
> > << \
> > + BUG_LINE_LO_WIDTH)
> > + \
> > + (((b)->line_lo + ((b)->ptr_disp < 0))
> > & \
> > + ((1 << BUG_LINE_LO_WIDTH) - 1)))
> > +
> > +#define bug_msg(b) ((const char *)(b) + (b)->msg_disp[1])
>
> As indicated earlier, I think that you want to move here what you
> currently have ...
>
> > +#endif /* BUG_FRAME_STRUCT */
> > +
> > +/*
> > + * Some architectures mark immediate instruction operands in a
> > special way.
> > + * In such cases the special marking may need omitting when
> > specifying
> > + * directive operands. Allow architectures to specify a suitable
> > + * modifier.
> > + */
> > +#ifndef BUG_ASM_CONST
> > +#define BUG_ASM_CONST ""
> > +#endif
> > +
> > +#ifndef _ASM_BUGFRAME_TEXT
> > +
> > +#define
> > _ASM_BUGFRAME_TEXT(second_frame)
> > \
> > +
> > ".Lbug%=:"BUG_INSTR"\n"
> > \
> > + " .pushsection .bug_frames.%"BUG_ASM_CONST"[bf_type], \"a\",
> > %%progbits\n" \
> > + " .p2align
> > 2\n"
> > \
> > +
> > ".Lfrm%=:\n"
> > \
> > + " .long (.Lbug%= - .Lfrm%=) +
> > %"BUG_ASM_CONST"[bf_line_hi]\n" \
> > + " .long (%"BUG_ASM_CONST"[bf_ptr] - .Lfrm%=) +
> > %"BUG_ASM_CONST"[bf_line_lo]\n"\
> > + " .if " #second_frame
> > "\n" \
> > + " .long 0, %"BUG_ASM_CONST"[bf_msg] -
> > .Lfrm%=\n" \
> > + "
> > .endif\n"
> > \
> > + " .popsection\n"
> > +
> > +#define _ASM_BUGFRAME_INFO(type, line, ptr,
> > msg) \
> > + [bf_type] "i"
> > (type), \
> > + [bf_ptr] "i"
> > (ptr), \
> > + [bf_msg] "i"
> > (msg), \
> > + [bf_line_lo] "i" ((line & ((1 << BUG_LINE_LO_WIDTH) -
> > 1)) \
> > + <<
> > BUG_DISP_WIDTH), \
> > + [bf_line_hi] "i" (((line) >> BUG_LINE_LO_WIDTH) <<
> > BUG_DISP_WIDTH)
> > +
> > +#endif /* _ASM_BUGFRAME_TEXT */
> > +
> > +#ifndef BUILD_BUG_ON_LINE_WIDTH
> > +#define BUILD_BUG_ON_LINE_WIDTH(line) \
> > + BUILD_BUG_ON((line) >> (BUG_LINE_LO_WIDTH +
> > BUG_LINE_HI_WIDTH))
> > +#endif
>
> ... here, guarded by a separate #ifdef. The check is specifically
> tied to
> the struct layout chosen here. Instead what you want here is
>
> #ifndef BUILD_BUG_ON_LINE_WIDTH
> #define BUILD_BUG_ON_LINE_WIDTH(line) ((void)(line))
> #endif
>
> covering architectures using a different layout where such a check
> isn't
> needed. Of course this also could move up and simply become "#elif
> ..."
> to the earlier "#if !defined(BUG_FRAME_STRUCT)", which would keep
> related things together.
>
The logic behind this was the following. <xen/bug.h> is the generic
implementation which is based on BUG_LINE_{LO,HI}_WIDTH and if
architecture would like to use another one implementation than it
should re-define BUILD_BUG_ON_LINE_WIDTH.
But it might be better to move my 'ifndef BUILD_BUG_ON_LINE_WIDTH' to
'ifndef BUG_FRAME' and instead of it put dummy BUILD_BUG_ON_LINE_WIDTH.
> > +#ifndef BUG_FRAME
> > +
> > +#define BUG_FRAME(type, line, ptr, second_frame, msg) do
> > { \
> > +
> > BUILD_BUG_ON_LINE_WIDTH(line);
> > \
> > + BUILD_BUG_ON((type) >=
> > BUGFRAME_NR); \
> > + asm volatile (
> > _ASM_BUGFRAME_TEXT(second_frame) \
> > + :: _ASM_BUGFRAME_INFO(type, line, ptr, msg)
> > ); \
> > +} while (false)
>
> Nit: Style.
Oh. It should be changed to ( false ) in each macros.
>
> > +
> > +#endif
> > +
> > +#ifndef run_in_exception_handler
> > +
> > +/*
> > + * 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().
> > + */
> > +#define run_in_exception_handler(fn) do { \
> > + (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
>
> Hmm, there's another const-ness anomaly that has slipped in (and is
> no longer necessary with do_bug_frame() now again taking a pointer to
> non-const): At the point you handle BUGFRAME_run_fn the type used
> (wrongly) is void (*)(const struct cpu_user_regs *).
>
> The disconnect isn't good to leave (as the same issue could be
> introduced later, when not looking closely enough). While not for
> this patch, I wonder if we shouldn't make the use site be something
> along the lines of
>
> if ( id == BUGFRAME_run_fn )
> {
> void (*fn)(struct cpu_user_regs *) = bug_ptr(bug);
>
> fn(regs);
>
> /* Re-enforce consistent types, because of the casts
> involved. */
> if ( false )
> run_in_exception_handler(fn);
>
> return id;
> }
>
> just to make sure the type used in run_in_exception_handler()
> matches the one used here (without actually producing any code).
>
It looks like it is really make sense to add this check so I will
take it into account in the next version of the patch series.
Thanks.
~ Oleksii
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h>
2023-03-08 15:27 ` Jan Beulich
@ 2023-03-08 17:25 ` Oleksii
2023-03-09 9:49 ` Jan Beulich
0 siblings, 1 reply; 12+ messages in thread
From: Oleksii @ 2023-03-08 17:25 UTC (permalink / raw
To: Jan Beulich
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
Bertrand Marquis, Volodymyr Babchuk, George Dunlap, Wei Liu,
Roger Pau Monné, xen-devel
On Wed, 2023-03-08 at 16:27 +0100, Jan Beulich wrote:
> On 07.03.2023 16:50, Oleksii Kurochko wrote:
> > --- a/xen/arch/arm/include/asm/bug.h
> > +++ b/xen/arch/arm/include/asm/bug.h
> > @@ -1,6 +1,8 @@
> > #ifndef __ARM_BUG_H__
> > #define __ARM_BUG_H__
> >
> > +#include <xen/types.h>
> > +
> > #if defined(CONFIG_ARM_32)
> > # include <asm/arm32/bug.h>
> > #elif defined(CONFIG_ARM_64)
> > @@ -9,10 +11,16 @@
> > # error "unknown ARM variant"
> > #endif
> >
> > +#undef BUG_DISP_WIDTH
> > +#undef BUG_LINE_LO_WIDTH
> > +#undef BUG_LINE_HI_WIDTH
>
> Why? For Arm ...
>
> > #define BUG_DISP_WIDTH 24
> > #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> > #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
>
> ... you could purge these as unused, even in a standalone prereq
> patch.
> And on x86 ...
>
> > --- a/xen/arch/x86/include/asm/bug.h
> > +++ b/xen/arch/x86/include/asm/bug.h
> > @@ -1,19 +1,18 @@
> > #ifndef __X86_BUG_H__
> > #define __X86_BUG_H__
> >
> > +#undef BUG_DISP_WIDTH
> > +#undef BUG_LINE_LO_WIDTH
> > +#undef BUG_LINE_HI_WIDTH
> > +
> > #define BUG_DISP_WIDTH 24
> > #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
> > #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
>
> ... there's no reason to #undef just to the #define again to the same
> values. All of this would be removed in a subsequent patch anyway,
> and
> it's less code churn (with code nevertheless being correct) if you
> get
> rid of the #define-s right away (as iirc you had it in an earlier
> version). If you agree then with these adjustments
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
It won't be compilation issue (redefinition) in the current one case
because defines are the same as in <xen/bug.h> so it is possible to not
add #undef in this patch.
~ Oleksii
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation of bug.h
2023-03-08 15:33 ` Jan Beulich
@ 2023-03-08 17:48 ` Oleksii
0 siblings, 0 replies; 12+ messages in thread
From: Oleksii @ 2023-03-08 17:48 UTC (permalink / raw
To: Jan Beulich
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
Roger Pau Monné, Wei Liu, xen-devel
On Wed, 2023-03-08 at 16:33 +0100, Jan Beulich wrote:
> On 07.03.2023 16:50, Oleksii Kurochko wrote:
> > @@ -1166,12 +1167,9 @@ void cpuid_hypervisor_leaves(const struct
> > vcpu *v, uint32_t leaf,
> >
> > void do_invalid_op(struct cpu_user_regs *regs)
> > {
> > - const struct bug_frame *bug = NULL;
> > u8 bug_insn[2];
> > - const char *prefix = "", *filename, *predicate, *eip = (char
> > *)regs->rip;
> > - unsigned long fixup;
> > - int id = -1, lineno;
> > - const struct virtual_region *region;
> > + void *eip = (void *)regs->rip;
>
> As said elsewhere already: "const" please whenever possible. The more
> that
> the variable was pointer-to-const before.
Sure, I will change it than to:
const void *eip = (const void *)regs->rip;
>
> > @@ -1185,83 +1183,20 @@ void do_invalid_op(struct cpu_user_regs
> > *regs)
> > memcmp(bug_insn, "\xf\xb", sizeof(bug_insn)) )
> > goto die;
> >
> > - region = find_text_region(regs->rip);
> > - if ( region )
> > - {
> > - for ( id = 0; id < BUGFRAME_NR; id++ )
> > - {
> > - const struct bug_frame *b;
> > - unsigned int i;
> > -
> > - for ( i = 0, b = region->frame[id].bugs;
> > - i < region->frame[id].n_bugs; b++, i++ )
> > - {
> > - if ( bug_loc(b) == eip )
> > - {
> > - bug = b;
> > - goto found;
> > - }
> > - }
> > - }
> > - }
> > -
> > - found:
> > - if ( !bug )
> > + id = do_bug_frame(regs, regs->rip);
> > + if ( id < 0 )
> > goto die;
> > - eip += sizeof(bug_insn);
> > - if ( id == BUGFRAME_run_fn )
> > - {
> > - void (*fn)(struct cpu_user_regs *) = bug_ptr(bug);
> > -
> > - fn(regs);
> > - fixup_exception_return(regs, (unsigned long)eip);
> > - return;
> > - }
> >
> > - /* WARN, BUG or ASSERT: decode the filename pointer and line
> > number. */
> > - filename = bug_ptr(bug);
> > - if ( !is_kernel(filename) && !is_patch(filename) )
> > - goto die;
> > - fixup = strlen(filename);
> > - if ( fixup > 50 )
> > - {
> > - filename += fixup - 47;
> > - prefix = "...";
> > - }
> > - lineno = bug_line(bug);
> > + eip = (unsigned char *)eip + sizeof(bug_insn);
>
> Why don't you keep the original
>
> eip += sizeof(bug_insn);
>
> ? As also said before we use the GNU extension of arithmetic on
> pointers
> to void pretty extensively elsewhere; there's no reason at all to
> introduce an unnecessary and questionable cast here.
Just missed that during rebase. ( I experimented with the branch and
received conflicts that were resolved incorrectly )
I will update that. Thanks
>
> With these adjustments and with the re-basing over the changes
> requested
> to patch 2
> Reviewed-by: Jan Beulich <jbeulich@suse.com>
>
> Jan
~ Oleksii
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h>
2023-03-08 17:25 ` Oleksii
@ 2023-03-09 9:49 ` Jan Beulich
0 siblings, 0 replies; 12+ messages in thread
From: Jan Beulich @ 2023-03-09 9:49 UTC (permalink / raw
To: Oleksii
Cc: Julien Grall, Andrew Cooper, Stefano Stabellini, Gianluca Guida,
Bertrand Marquis, Volodymyr Babchuk, George Dunlap, Wei Liu,
Roger Pau Monné, xen-devel
On 08.03.2023 18:25, Oleksii wrote:
> On Wed, 2023-03-08 at 16:27 +0100, Jan Beulich wrote:
>> On 07.03.2023 16:50, Oleksii Kurochko wrote:
>>> --- a/xen/arch/arm/include/asm/bug.h
>>> +++ b/xen/arch/arm/include/asm/bug.h
>>> @@ -1,6 +1,8 @@
>>> #ifndef __ARM_BUG_H__
>>> #define __ARM_BUG_H__
>>>
>>> +#include <xen/types.h>
>>> +
>>> #if defined(CONFIG_ARM_32)
>>> # include <asm/arm32/bug.h>
>>> #elif defined(CONFIG_ARM_64)
>>> @@ -9,10 +11,16 @@
>>> # error "unknown ARM variant"
>>> #endif
>>>
>>> +#undef BUG_DISP_WIDTH
>>> +#undef BUG_LINE_LO_WIDTH
>>> +#undef BUG_LINE_HI_WIDTH
>>
>> Why? For Arm ...
>>
>>> #define BUG_DISP_WIDTH 24
>>> #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
>>> #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
>>
>> ... you could purge these as unused, even in a standalone prereq
>> patch.
>> And on x86 ...
>>
>>> --- a/xen/arch/x86/include/asm/bug.h
>>> +++ b/xen/arch/x86/include/asm/bug.h
>>> @@ -1,19 +1,18 @@
>>> #ifndef __X86_BUG_H__
>>> #define __X86_BUG_H__
>>>
>>> +#undef BUG_DISP_WIDTH
>>> +#undef BUG_LINE_LO_WIDTH
>>> +#undef BUG_LINE_HI_WIDTH
>>> +
>>> #define BUG_DISP_WIDTH 24
>>> #define BUG_LINE_LO_WIDTH (31 - BUG_DISP_WIDTH)
>>> #define BUG_LINE_HI_WIDTH (31 - BUG_DISP_WIDTH)
>>
>> ... there's no reason to #undef just to the #define again to the same
>> values. All of this would be removed in a subsequent patch anyway,
>> and
>> it's less code churn (with code nevertheless being correct) if you
>> get
>> rid of the #define-s right away (as iirc you had it in an earlier
>> version). If you agree then with these adjustments
>> Reviewed-by: Jan Beulich <jbeulich@suse.com>
>
> It won't be compilation issue (redefinition) in the current one case
> because defines are the same as in <xen/bug.h> so it is possible to not
> add #undef in this patch.
Avoiding to add the #undef is the minimal approach. Yet as indicated I
think the #define-s should also be dropped right here (x86) and in a
prereq patch (Arm).
Jan
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2023-03-09 9:50 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-03-07 15:50 [PATCH v6 0/4] [PATCH v5 0/4] introduce generic implementation of macros from bug.h Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 1/4] xen: introduce CONFIG_GENERIC_BUG_FRAME Oleksii Kurochko
2023-03-08 15:06 ` Jan Beulich
2023-03-08 17:18 ` Oleksii
2023-03-07 15:50 ` [PATCH v6 2/4] xen: change <asm/bug.h> to <xen/bug.h> Oleksii Kurochko
2023-03-08 15:27 ` Jan Beulich
2023-03-08 17:25 ` Oleksii
2023-03-09 9:49 ` Jan Beulich
2023-03-07 15:50 ` [PATCH v6 3/4] xen/arm: switch ARM to use generic implementation of bug.h Oleksii Kurochko
2023-03-07 15:50 ` [PATCH v6 4/4] xen/x86: switch x86 to use generic implemetation " Oleksii Kurochko
2023-03-08 15:33 ` Jan Beulich
2023-03-08 17:48 ` Oleksii
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