[PATCH 4/7] tools/nolibc: handle 64-bit system call arguments on x32
From: Thomas Weißschuh
Date: Sat Apr 18 2026 - 06:21:16 EST
The x32 system call ABI expects 64-bit values directly in registers.
This does not work on nolibc currently, as a 'long' is only 32 bits
wide. Switch the system call wrappers to use 'long long' instead which
can handle 64-bit values on x32. As on x86_64 'long' and 'long long' are
the same, this does not change the behavior there.
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
tools/include/nolibc/arch-x86.h | 70 ++++++++++++++++++++---------------------
1 file changed, 35 insertions(+), 35 deletions(-)
diff --git a/tools/include/nolibc/arch-x86.h b/tools/include/nolibc/arch-x86.h
index 769ba01a8629..7a0882c6e942 100644
--- a/tools/include/nolibc/arch-x86.h
+++ b/tools/include/nolibc/arch-x86.h
@@ -202,8 +202,8 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall0(num) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -216,9 +216,9 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall1(num, arg1) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -232,10 +232,10 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall2(num, arg1, arg2) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
- register long _arg2 __asm__ ("rsi") = (long)(arg2); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
+ register long long _arg2 __asm__ ("rsi") = __nolibc_arg_to_reg(arg2); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -249,11 +249,11 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall3(num, arg1, arg2, arg3) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
- register long _arg2 __asm__ ("rsi") = (long)(arg2); \
- register long _arg3 __asm__ ("rdx") = (long)(arg3); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
+ register long long _arg2 __asm__ ("rsi") = __nolibc_arg_to_reg(arg2); \
+ register long long _arg3 __asm__ ("rdx") = __nolibc_arg_to_reg(arg3); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -267,12 +267,12 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
- register long _arg2 __asm__ ("rsi") = (long)(arg2); \
- register long _arg3 __asm__ ("rdx") = (long)(arg3); \
- register long _arg4 __asm__ ("r10") = (long)(arg4); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
+ register long long _arg2 __asm__ ("rsi") = __nolibc_arg_to_reg(arg2); \
+ register long long _arg3 __asm__ ("rdx") = __nolibc_arg_to_reg(arg3); \
+ register long long _arg4 __asm__ ("r10") = __nolibc_arg_to_reg(arg4); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -286,13 +286,13 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
- register long _arg2 __asm__ ("rsi") = (long)(arg2); \
- register long _arg3 __asm__ ("rdx") = (long)(arg3); \
- register long _arg4 __asm__ ("r10") = (long)(arg4); \
- register long _arg5 __asm__ ("r8") = (long)(arg5); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
+ register long long _arg2 __asm__ ("rsi") = __nolibc_arg_to_reg(arg2); \
+ register long long _arg3 __asm__ ("rdx") = __nolibc_arg_to_reg(arg3); \
+ register long long _arg4 __asm__ ("r10") = __nolibc_arg_to_reg(arg4); \
+ register long long _arg5 __asm__ ("r8") = __nolibc_arg_to_reg(arg5); \
\
__asm__ volatile ( \
"syscall\n" \
@@ -306,14 +306,14 @@ void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _s
#define __nolibc_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
- long _ret; \
- register long _num __asm__ ("rax") = (num); \
- register long _arg1 __asm__ ("rdi") = (long)(arg1); \
- register long _arg2 __asm__ ("rsi") = (long)(arg2); \
- register long _arg3 __asm__ ("rdx") = (long)(arg3); \
- register long _arg4 __asm__ ("r10") = (long)(arg4); \
- register long _arg5 __asm__ ("r8") = (long)(arg5); \
- register long _arg6 __asm__ ("r9") = (long)(arg6); \
+ long long _ret; \
+ register long long _num __asm__ ("rax") = (num); \
+ register long long _arg1 __asm__ ("rdi") = __nolibc_arg_to_reg(arg1); \
+ register long long _arg2 __asm__ ("rsi") = __nolibc_arg_to_reg(arg2); \
+ register long long _arg3 __asm__ ("rdx") = __nolibc_arg_to_reg(arg3); \
+ register long long _arg4 __asm__ ("r10") = __nolibc_arg_to_reg(arg4); \
+ register long long _arg5 __asm__ ("r8") = __nolibc_arg_to_reg(arg5); \
+ register long long _arg6 __asm__ ("r9") = __nolibc_arg_to_reg(arg6); \
\
__asm__ volatile ( \
"syscall\n" \
--
2.53.0