[PATCH] um: Add cmpxchg8b_emu and checksum functions to asm-prototypes.h

From: Sami Tolvanen
Date: Wed Mar 26 2025 - 15:05:20 EST


With CONFIG_GENDWARFKSYMS, um builds fail due to missing prototypes
in asm/asm-prototypes.h. Add declarations for cmpxchg8b_emu and the
exported checksum functions, including csum_partial_copy_generic as
it's also exported.

Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: linux-kbuild@xxxxxxxxxxxxxxx
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202503251216.lE4t9Ikj-lkp@xxxxxxxxx/
Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
---
arch/um/include/asm/asm-prototypes.h | 5 +++++
arch/x86/um/asm/checksum.h | 3 +++
2 files changed, 8 insertions(+)

diff --git a/arch/um/include/asm/asm-prototypes.h b/arch/um/include/asm/asm-prototypes.h
index 5898a26daa0d..408b31d59127 100644
--- a/arch/um/include/asm/asm-prototypes.h
+++ b/arch/um/include/asm/asm-prototypes.h
@@ -1 +1,6 @@
#include <asm-generic/asm-prototypes.h>
+#include <asm/checksum.h>
+
+#ifdef CONFIG_UML_X86
+extern void cmpxchg8b_emu(void);
+#endif
diff --git a/arch/x86/um/asm/checksum.h b/arch/x86/um/asm/checksum.h
index b07824500363..ddc144657efa 100644
--- a/arch/x86/um/asm/checksum.h
+++ b/arch/x86/um/asm/checksum.h
@@ -20,6 +20,9 @@
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);

+/* Do not call this directly. Declared for export type visibility. */
+extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
+
/**
* csum_fold - Fold and invert a 32bit checksum.
* sum: 32bit unfolded sum

base-commit: f6e0150b2003fb2b9265028a618aa1732b3edc8f
--
2.49.0.395.g12beb8f557-goog