parisc: add support for suppressing warning backtraces

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.

Link: https://lkml.kernel.org/r/20250313114329.284104-10-acarmina@redhat.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alessandro Carminati <acarmina@redhat.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Arthur Grillo <arthurgrillo@riseup.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Daniel Diaz <daniel.diaz@linaro.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Gow <davidgow@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maíra Canal <mcanal@igalia.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Rae Moar <rmoar@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/parisc/include/asm/bug.h b/arch/parisc/include/asm/bug.h
index 833555f74ffa7241a44af41f58b32164ba381169..b59c3f7380bf24bcca421737863911bd50e2d5c8 100644 (file)
--- 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)) );          \