diff options
| -rw-r--r-- | tools/include/nolibc/nolibc.h | 33 |
1 files changed, 19 insertions, 14 deletions
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h index 3e2c6f2ed587..f9afe89ec6f2 100644 --- a/tools/include/nolibc/nolibc.h +++ b/tools/include/nolibc/nolibc.h @@ -265,12 +265,17 @@ struct stat { * - arguments are in rdi, rsi, rdx, r10, r8, r9 respectively * - the system call is performed by calling the syscall instruction * - syscall return comes in rax - * - rcx and r8..r11 may be clobbered, others are preserved. + * - rcx and r11 are clobbered, others are preserved. * - the arguments are cast to long and assigned into the target registers * which are then simply passed as registers to the asm code, so that we * don't have to experience issues with register constraints. * - the syscall number is always specified last in order to allow to force * some registers before (gcc refuses a %-register at the last position). + * - see also x86-64 ABI section A.2 AMD64 Linux Kernel Conventions, A.2.1 + * Calling Conventions. + * + * Link x86-64 ABI: https://gitlab.com/x86-psABIs/x86-64-ABI/-/wikis/x86-64-psABI + * */ #define my_syscall0(num) \ @@ -280,9 +285,9 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret) \ + : "=a"(_ret) \ : "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -295,10 +300,10 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret) \ + : "=a"(_ret) \ : "r"(_arg1), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -312,10 +317,10 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret) \ + : "=a"(_ret) \ : "r"(_arg1), "r"(_arg2), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -330,10 +335,10 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret) \ + : "=a"(_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), \ "0"(_num) \ - : "rcx", "r8", "r9", "r10", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -349,10 +354,10 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret), "=r"(_arg4) \ + : "=a"(_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \ "0"(_num) \ - : "rcx", "r8", "r9", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -369,10 +374,10 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \ + : "=a"(_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ "0"(_num) \ - : "rcx", "r9", "r11", "memory", "cc" \ + : "rcx", "r11", "memory", "cc" \ ); \ _ret; \ }) @@ -390,7 +395,7 @@ struct stat { \ asm volatile ( \ "syscall\n" \ - : "=a" (_ret), "=r"(_arg4), "=r"(_arg5) \ + : "=a"(_ret) \ : "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \ "r"(_arg6), "0"(_num) \ : "rcx", "r11", "memory", "cc" \ |