From: Sagi Shahar <[email protected]> Add the Kbuild macros needed to enable the filechk_offsets mechanism to generate C header files containing structure member offset information.
Tools depending on assembly code that operate on structures have to hardcode the offsets of structure members. The Kbuild infrastructure can instead generate C header files with these offsets automatically, allowing them to be included in assembly code as symbolic constants. For example, the TDX guest boot code requires access to parameters passed in the C structure(struct td_boot_parameters). This header provides the macros needed to extract these offsets from C code and expose them to assembly, ensuring the two remain synchronized. Signed-off-by: Sagi Shahar <[email protected]> Reviewed-by: Ira Weiny <[email protected]> Signed-off-by: Lisa Wang <[email protected]> --- tools/include/linux/kbuild.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/tools/include/linux/kbuild.h b/tools/include/linux/kbuild.h new file mode 100644 index 000000000000..957fd55cd159 --- /dev/null +++ b/tools/include/linux/kbuild.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __TOOLS_LINUX_KBUILD_H +#define __TOOLS_LINUX_KBUILD_H + +#define DEFINE(sym, val) \ + asm volatile("\n.ascii \"->" #sym " %0 " #val "\"" : : "i" (val)) + +#define OFFSET(sym, str, mem) \ + DEFINE(sym, __builtin_offsetof(struct str, mem)) + +#endif /* __TOOLS_LINUX_KBUILD_H */ -- 2.54.0.746.g67dd491aae-goog
