From: Joe Richey <redacted>
The BIT(n) macro is used in the kernel as an alias for (1 << n).
However, it is not defined in the UAPI headers, they should instead use
the _BITUL(n) macro. This patch chages all existing usages in UAPI
headers and updates ./scripts/checkpatch.pl to properly reccomend the
correct macro depending on context.
Running the below commands shows no more incorrect macro usages:
rg "BIT\(" **/uapi/**
rg "BIT_ULL\(" **/uapi/**
Tested by building a basic kernel. Changes are trivial.
I encountered this issue when compiling the following program:
#include <sys/auxv.h>
#include <asm/hwcap2.h>
// Detect if FSGSBASE instructions are enabled
int main() {
unsigned long val = getauxval(AT_HWCAP2);
return !(val & HWCAP2_FSGSBASE);
}
Resulting in the following likner error:
/usr/bin/ld: /tmp/cceFpAdR.o: in function `main':
gs.c:(.text+0x21): undefined reference to `BIT'
Changes from V1 to V2:
- Use _BITUL() macro instead of open-coding
- Fixup HWCAP2_RING3MWAIT as well
- Shorten commits and added "Fixes" per reviewer comments
- checkpatch: Broaden UAPI regex
- checkpatch: Reccomend _BITULL()/_BITUL() for UAPI headers
Joe Richey (7):
x86/elf: Use _BITUL() macro in UAPI headers
KVM: X86: Use _BITUL() macro in UAPI headers
drivers: firmware: psci: Use _BITUL() macro in UAPI headers
uacce: Use _BITUL() macro in UAPI headers
media: vicodec: Use _BITUL() macro in UAPI headers
tools headers UAPI: Sync pkt_sched.h with the kernel sources
checkpatch: suggest _BITULL() and _BITUL() for UAPI headers
arch/x86/include/uapi/asm/hwcap2.h | 6 +-
include/uapi/linux/kvm.h | 5 +-
include/uapi/linux/psci.h | 4 +-
include/uapi/linux/v4l2-controls.h | 23 ++---
include/uapi/misc/uacce/uacce.h | 3 +-
scripts/checkpatch.pl | 16 ++--
tools/include/uapi/linux/kvm.h | 5 +-
tools/include/uapi/linux/pkt_sched.h | 122 ++++++++++++++++++++++++---
8 files changed, 148 insertions(+), 36 deletions(-)
--
2.31.1