Add name of functions triggering warning backtraces to the __bug_table
object section to enable support for suppressing WARNING backtraces.

To limit image size impact, the pointer to the function name is only added
to the __bug_table section if both CONFIG_KUNIT_SUPPRESS_BACKTRACE and
CONFIG_DEBUG_BUGVERBOSE are enabled. Otherwise, the __func__ assembly
parameter is replaced with a (dummy) NULL parameter to avoid an image size
increase due to unused __func__ entries (this is necessary because __func__
is not a define but a virtual variable).

While at it, declare assembler parameters as constants where possible.
Refine .blockz instructions to calculate the necessary padding instead
of using fixed values.

Tested-by: Linux Kernel Functional Testing <l...@linaro.org>
Acked-by: Dan Carpenter <dan.carpen...@linaro.org>
Acked-by: Helge Deller <del...@gmx.de>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
v2:
- Rebased to v6.9-rc1
- Added Tested-by:, Acked-by:, and Reviewed-by: tags
- Introduced KUNIT_SUPPRESS_BACKTRACE configuration option
v3:
- Rebased to v6.9-rc2

 arch/parisc/include/asm/bug.h | 29 +++++++++++++++++++++--------
 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/arch/parisc/include/asm/bug.h b/arch/parisc/include/asm/bug.h
index 833555f74ffa..b59c3f7380bf 100644
--- a/arch/parisc/include/asm/bug.h
+++ b/arch/parisc/include/asm/bug.h
@@ -23,8 +23,17 @@
 # define __BUG_REL(val) ".word " __stringify(val)
 #endif
 
-
 #ifdef CONFIG_DEBUG_BUGVERBOSE
+
+#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE
+# define HAVE_BUG_FUNCTION
+# define __BUG_FUNC_PTR        __BUG_REL(%c1)
+# define __BUG_FUNC    __func__
+#else
+# define __BUG_FUNC_PTR
+# define __BUG_FUNC    NULL
+#endif /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */
+
 #define BUG()                                                          \
        do {                                                            \
                asm volatile("\n"                                       \
@@ -33,10 +42,12 @@
                             "\t.align 4\n"                             \
                             "2:\t" __BUG_REL(1b) "\n"                  \
                             "\t" __BUG_REL(%c0)  "\n"                  \
-                            "\t.short %1, %2\n"                        \
-                            "\t.blockz %3-2*4-2*2\n"                   \
+                            "\t" __BUG_FUNC_PTR  "\n"                  \
+                            "\t.short %c2, %c3\n"                      \
+                            "\t.blockz %c4-(.-2b)\n"                   \
                             "\t.popsection"                            \
-                            : : "i" (__FILE__), "i" (__LINE__),        \
+                            : : "i" (__FILE__), "i" (__BUG_FUNC),      \
+                            "i" (__LINE__),                            \
                             "i" (0), "i" (sizeof(struct bug_entry)) ); \
                unreachable();                                          \
        } while(0)
@@ -58,10 +69,12 @@
                             "\t.align 4\n"                             \
                             "2:\t" __BUG_REL(1b) "\n"                  \
                             "\t" __BUG_REL(%c0)  "\n"                  \
-                            "\t.short %1, %2\n"                        \
-                            "\t.blockz %3-2*4-2*2\n"                   \
+                            "\t" __BUG_FUNC_PTR  "\n"                  \
+                            "\t.short %c2, %3\n"                       \
+                            "\t.blockz %c4-(.-2b)\n"                   \
                             "\t.popsection"                            \
-                            : : "i" (__FILE__), "i" (__LINE__),        \
+                            : : "i" (__FILE__), "i" (__BUG_FUNC),      \
+                            "i" (__LINE__),                            \
                             "i" (BUGFLAG_WARNING|(flags)),             \
                             "i" (sizeof(struct bug_entry)) );          \
        } while(0)
@@ -74,7 +87,7 @@
                             "\t.align 4\n"                             \
                             "2:\t" __BUG_REL(1b) "\n"                  \
                             "\t.short %0\n"                            \
-                            "\t.blockz %1-4-2\n"                       \
+                            "\t.blockz %c1-(.-2b)\n"                   \
                             "\t.popsection"                            \
                             : : "i" (BUGFLAG_WARNING|(flags)),         \
                             "i" (sizeof(struct bug_entry)) );          \
-- 
2.39.2

Reply via email to