1fa697140SDominik Brodowski /* SPDX-License-Identifier: GPL-2.0 */ 2fa697140SDominik Brodowski /* 3fa697140SDominik Brodowski * syscall_wrapper.h - x86 specific wrappers to syscall definitions 4fa697140SDominik Brodowski */ 5fa697140SDominik Brodowski 6fa697140SDominik Brodowski #ifndef _ASM_X86_SYSCALL_WRAPPER_H 7fa697140SDominik Brodowski #define _ASM_X86_SYSCALL_WRAPPER_H 8fa697140SDominik Brodowski 96e484764SSami Tolvanen struct pt_regs; 106e484764SSami Tolvanen 11ebeb8c82SDominik Brodowski /* Mapping of registers to parameters for syscalls on x86-64 and x32 */ 12ebeb8c82SDominik Brodowski #define SC_X86_64_REGS_TO_ARGS(x, ...) \ 13ebeb8c82SDominik Brodowski __MAP(x,__SC_ARGS \ 14ebeb8c82SDominik Brodowski ,,regs->di,,regs->si,,regs->dx \ 15ebeb8c82SDominik Brodowski ,,regs->r10,,regs->r8,,regs->r9) \ 16ebeb8c82SDominik Brodowski 17ebeb8c82SDominik Brodowski /* Mapping of registers to parameters for syscalls on i386 */ 18ebeb8c82SDominik Brodowski #define SC_IA32_REGS_TO_ARGS(x, ...) \ 19ebeb8c82SDominik Brodowski __MAP(x,__SC_ARGS \ 20ebeb8c82SDominik Brodowski ,,(unsigned int)regs->bx,,(unsigned int)regs->cx \ 21ebeb8c82SDominik Brodowski ,,(unsigned int)regs->dx,,(unsigned int)regs->si \ 22ebeb8c82SDominik Brodowski ,,(unsigned int)regs->di,,(unsigned int)regs->bp) 23ebeb8c82SDominik Brodowski 24d2b5de49SBrian Gerst #define __SYS_STUB0(abi, name) \ 25d2b5de49SBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs); \ 26d2b5de49SBrian Gerst ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ 27d2b5de49SBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs) \ 28d2b5de49SBrian Gerst __alias(__do_##name); 29d2b5de49SBrian Gerst 304399e0cfSBrian Gerst #define __SYS_STUBx(abi, name, ...) \ 314399e0cfSBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs); \ 324399e0cfSBrian Gerst ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ 334399e0cfSBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs) \ 344399e0cfSBrian Gerst { \ 354399e0cfSBrian Gerst return __se_##name(__VA_ARGS__); \ 364399e0cfSBrian Gerst } 374399e0cfSBrian Gerst 386cc8d2b2SBrian Gerst #define __COND_SYSCALL(abi, name) \ 396cc8d2b2SBrian Gerst asmlinkage __weak long \ 406cc8d2b2SBrian Gerst __##abi##_##name(const struct pt_regs *__unused) \ 416cc8d2b2SBrian Gerst { \ 426cc8d2b2SBrian Gerst return sys_ni_syscall(); \ 436cc8d2b2SBrian Gerst } 446cc8d2b2SBrian Gerst 45a74d187cSBrian Gerst #define __SYS_NI(abi, name) \ 46a74d187cSBrian Gerst SYSCALL_ALIAS(__##abi##_##name, sys_ni_posix_timers) 47a74d187cSBrian Gerst 484399e0cfSBrian Gerst #ifdef CONFIG_X86_64 49d2b5de49SBrian Gerst #define __X64_SYS_STUB0(name) \ 50d2b5de49SBrian Gerst __SYS_STUB0(x64, sys_##name) 51d2b5de49SBrian Gerst 524399e0cfSBrian Gerst #define __X64_SYS_STUBx(x, name, ...) \ 534399e0cfSBrian Gerst __SYS_STUBx(x64, sys##name, \ 544399e0cfSBrian Gerst SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__)) 556cc8d2b2SBrian Gerst 566cc8d2b2SBrian Gerst #define __X64_COND_SYSCALL(name) \ 576cc8d2b2SBrian Gerst __COND_SYSCALL(x64, sys_##name) 58a74d187cSBrian Gerst 59a74d187cSBrian Gerst #define __X64_SYS_NI(name) \ 60a74d187cSBrian Gerst __SYS_NI(x64, sys_##name) 614399e0cfSBrian Gerst #else /* CONFIG_X86_64 */ 62d2b5de49SBrian Gerst #define __X64_SYS_STUB0(name) 634399e0cfSBrian Gerst #define __X64_SYS_STUBx(x, name, ...) 646cc8d2b2SBrian Gerst #define __X64_COND_SYSCALL(name) 65a74d187cSBrian Gerst #define __X64_SYS_NI(name) 664399e0cfSBrian Gerst #endif /* CONFIG_X86_64 */ 674399e0cfSBrian Gerst 68ebeb8c82SDominik Brodowski #ifdef CONFIG_IA32_EMULATION 69ebeb8c82SDominik Brodowski /* 70ebeb8c82SDominik Brodowski * For IA32 emulation, we need to handle "compat" syscalls *and* create 71e145242eSDominik Brodowski * additional wrappers (aptly named __ia32_sys_xyzzy) which decode the 72ebeb8c82SDominik Brodowski * ia32 regs in the proper order for shared or "common" syscalls. As some 73ebeb8c82SDominik Brodowski * syscalls may not be implemented, we need to expand COND_SYSCALL in 74ebeb8c82SDominik Brodowski * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this 75ebeb8c82SDominik Brodowski * case as well. 76ebeb8c82SDominik Brodowski */ 77d2b5de49SBrian Gerst #define __IA32_COMPAT_SYS_STUB0(name) \ 78d2b5de49SBrian Gerst __SYS_STUB0(ia32, compat_sys_##name) 79cf3b83e1SAndy Lutomirski 80c76fc982SDominik Brodowski #define __IA32_COMPAT_SYS_STUBx(x, name, ...) \ 814399e0cfSBrian Gerst __SYS_STUBx(ia32, compat_sys##name, \ 824399e0cfSBrian Gerst SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__)) 83ebeb8c82SDominik Brodowski 846cc8d2b2SBrian Gerst #define __IA32_COMPAT_COND_SYSCALL(name) \ 856cc8d2b2SBrian Gerst __COND_SYSCALL(ia32, compat_sys_##name) 866cc8d2b2SBrian Gerst 87a74d187cSBrian Gerst #define __IA32_COMPAT_SYS_NI(name) \ 88a74d187cSBrian Gerst __SYS_NI(ia32, compat_sys_##name) 89a74d187cSBrian Gerst 90d2b5de49SBrian Gerst #define __IA32_SYS_STUB0(name) \ 91d2b5de49SBrian Gerst __SYS_STUB0(ia32, sys_##name) 92d2b5de49SBrian Gerst 93c76fc982SDominik Brodowski #define __IA32_SYS_STUBx(x, name, ...) \ 944399e0cfSBrian Gerst __SYS_STUBx(ia32, sys##name, \ 954399e0cfSBrian Gerst SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__)) 96ebeb8c82SDominik Brodowski 976cc8d2b2SBrian Gerst #define __IA32_COND_SYSCALL(name) \ 986cc8d2b2SBrian Gerst __COND_SYSCALL(ia32, sys_##name) 99ebeb8c82SDominik Brodowski 100a74d187cSBrian Gerst #define __IA32_SYS_NI(name) \ 101a74d187cSBrian Gerst __SYS_NI(ia32, sys_##name) 102ebeb8c82SDominik Brodowski #else /* CONFIG_IA32_EMULATION */ 103d2b5de49SBrian Gerst #define __IA32_COMPAT_SYS_STUB0(name) 104c76fc982SDominik Brodowski #define __IA32_COMPAT_SYS_STUBx(x, name, ...) 1056cc8d2b2SBrian Gerst #define __IA32_COMPAT_COND_SYSCALL(name) 106a74d187cSBrian Gerst #define __IA32_COMPAT_SYS_NI(name) 107d2b5de49SBrian Gerst #define __IA32_SYS_STUB0(name) 1084399e0cfSBrian Gerst #define __IA32_SYS_STUBx(x, name, ...) 1096cc8d2b2SBrian Gerst #define __IA32_COND_SYSCALL(name) 110a74d187cSBrian Gerst #define __IA32_SYS_NI(name) 111ebeb8c82SDominik Brodowski #endif /* CONFIG_IA32_EMULATION */ 112ebeb8c82SDominik Brodowski 113ebeb8c82SDominik Brodowski 114ebeb8c82SDominik Brodowski #ifdef CONFIG_X86_X32 115ebeb8c82SDominik Brodowski /* 116ebeb8c82SDominik Brodowski * For the x32 ABI, we need to create a stub for compat_sys_*() which is aware 117ebeb8c82SDominik Brodowski * of the x86-64-style parameter ordering of x32 syscalls. The syscalls common 118ebeb8c82SDominik Brodowski * with x86_64 obviously do not need such care. 119ebeb8c82SDominik Brodowski */ 120d2b5de49SBrian Gerst #define __X32_COMPAT_SYS_STUB0(name) \ 121d2b5de49SBrian Gerst __SYS_STUB0(x32, compat_sys_##name) 122cf3b83e1SAndy Lutomirski 123c76fc982SDominik Brodowski #define __X32_COMPAT_SYS_STUBx(x, name, ...) \ 1244399e0cfSBrian Gerst __SYS_STUBx(x32, compat_sys##name, \ 1254399e0cfSBrian Gerst SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__)) 126ebeb8c82SDominik Brodowski 1276cc8d2b2SBrian Gerst #define __X32_COMPAT_COND_SYSCALL(name) \ 1286cc8d2b2SBrian Gerst __COND_SYSCALL(x32, compat_sys_##name) 129a74d187cSBrian Gerst 130a74d187cSBrian Gerst #define __X32_COMPAT_SYS_NI(name) \ 131a74d187cSBrian Gerst __SYS_NI(x32, compat_sys_##name) 132ebeb8c82SDominik Brodowski #else /* CONFIG_X86_X32 */ 133d2b5de49SBrian Gerst #define __X32_COMPAT_SYS_STUB0(name) 134c76fc982SDominik Brodowski #define __X32_COMPAT_SYS_STUBx(x, name, ...) 1356cc8d2b2SBrian Gerst #define __X32_COMPAT_COND_SYSCALL(name) 136a74d187cSBrian Gerst #define __X32_COMPAT_SYS_NI(name) 137ebeb8c82SDominik Brodowski #endif /* CONFIG_X86_X32 */ 138ebeb8c82SDominik Brodowski 139ebeb8c82SDominik Brodowski 140ebeb8c82SDominik Brodowski #ifdef CONFIG_COMPAT 141ebeb8c82SDominik Brodowski /* 142ebeb8c82SDominik Brodowski * Compat means IA32_EMULATION and/or X86_X32. As they use a different 143ebeb8c82SDominik Brodowski * mapping of registers to parameters, we need to generate stubs for each 144d5a00528SDominik Brodowski * of them. 145ebeb8c82SDominik Brodowski */ 146cf3b83e1SAndy Lutomirski #define COMPAT_SYSCALL_DEFINE0(name) \ 147d2b5de49SBrian Gerst static asmlinkage long \ 148d2b5de49SBrian Gerst __do_compat_sys_##name(const struct pt_regs *__unused); \ 149d2b5de49SBrian Gerst __IA32_COMPAT_SYS_STUB0(name) \ 150d2b5de49SBrian Gerst __X32_COMPAT_SYS_STUB0(name) \ 151d2b5de49SBrian Gerst static asmlinkage long \ 152d2b5de49SBrian Gerst __do_compat_sys_##name(const struct pt_regs *__unused) 153cf3b83e1SAndy Lutomirski 154ebeb8c82SDominik Brodowski #define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ 1555ac9efa3SDominik Brodowski static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ 1565ac9efa3SDominik Brodowski static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ 157c76fc982SDominik Brodowski __IA32_COMPAT_SYS_STUBx(x, name, __VA_ARGS__) \ 158c76fc982SDominik Brodowski __X32_COMPAT_SYS_STUBx(x, name, __VA_ARGS__) \ 1595ac9efa3SDominik Brodowski static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ 160ebeb8c82SDominik Brodowski { \ 1615ac9efa3SDominik Brodowski return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\ 162ebeb8c82SDominik Brodowski } \ 1635ac9efa3SDominik Brodowski static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) 164ebeb8c82SDominik Brodowski 165ebeb8c82SDominik Brodowski /* 166ebeb8c82SDominik Brodowski * As some compat syscalls may not be implemented, we need to expand 167ebeb8c82SDominik Brodowski * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in 168ebeb8c82SDominik Brodowski * kernel/time/posix-stubs.c to cover this case as well. 169ebeb8c82SDominik Brodowski */ 170ebeb8c82SDominik Brodowski #define COND_SYSCALL_COMPAT(name) \ 1716cc8d2b2SBrian Gerst __IA32_COMPAT_COND_SYSCALL(name) \ 1726cc8d2b2SBrian Gerst __X32_COMPAT_COND_SYSCALL(name) 173ebeb8c82SDominik Brodowski 174ebeb8c82SDominik Brodowski #define COMPAT_SYS_NI(name) \ 175a74d187cSBrian Gerst __IA32_COMPAT_SYS_NI(name) \ 176a74d187cSBrian Gerst __X32_COMPAT_SYS_NI(name) 177ebeb8c82SDominik Brodowski 178ebeb8c82SDominik Brodowski #endif /* CONFIG_COMPAT */ 179ebeb8c82SDominik Brodowski 180ebeb8c82SDominik Brodowski 181fa697140SDominik Brodowski /* 182fa697140SDominik Brodowski * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes 183fa697140SDominik Brodowski * struct pt_regs *regs as the only argument of the syscall stub named 184d5a00528SDominik Brodowski * __x64_sys_*(). It decodes just the registers it needs and passes them on to 185e145242eSDominik Brodowski * the __se_sys_*() wrapper performing sign extension and then to the 186e145242eSDominik Brodowski * __do_sys_*() function doing the actual job. These wrappers and functions 187e145242eSDominik Brodowski * are inlined (at least in very most cases), meaning that the assembly looks 188e145242eSDominik Brodowski * as follows (slightly re-ordered for better readability): 189fa697140SDominik Brodowski * 190d5a00528SDominik Brodowski * <__x64_sys_recv>: <-- syscall with 4 parameters 191fa697140SDominik Brodowski * callq <__fentry__> 192fa697140SDominik Brodowski * 193fa697140SDominik Brodowski * mov 0x70(%rdi),%rdi <-- decode regs->di 194fa697140SDominik Brodowski * mov 0x68(%rdi),%rsi <-- decode regs->si 195fa697140SDominik Brodowski * mov 0x60(%rdi),%rdx <-- decode regs->dx 196fa697140SDominik Brodowski * mov 0x38(%rdi),%rcx <-- decode regs->r10 197fa697140SDominik Brodowski * 198fa697140SDominik Brodowski * xor %r9d,%r9d <-- clear %r9 199fa697140SDominik Brodowski * xor %r8d,%r8d <-- clear %r8 200fa697140SDominik Brodowski * 201fa697140SDominik Brodowski * callq __sys_recvfrom <-- do the actual work in __sys_recvfrom() 202fa697140SDominik Brodowski * which takes 6 arguments 203fa697140SDominik Brodowski * 204fa697140SDominik Brodowski * cltq <-- extend return value to 64-bit 205fa697140SDominik Brodowski * retq <-- return 206fa697140SDominik Brodowski * 207fa697140SDominik Brodowski * This approach avoids leaking random user-provided register content down 208fa697140SDominik Brodowski * the call chain. 209fa697140SDominik Brodowski * 210ebeb8c82SDominik Brodowski * If IA32_EMULATION is enabled, this macro generates an additional wrapper 211e145242eSDominik Brodowski * named __ia32_sys_*() which decodes the struct pt_regs *regs according 212ebeb8c82SDominik Brodowski * to the i386 calling convention (bx, cx, dx, si, di, bp). 213fa697140SDominik Brodowski */ 214fa697140SDominik Brodowski #define __SYSCALL_DEFINEx(x, name, ...) \ 215e145242eSDominik Brodowski static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ 216e145242eSDominik Brodowski static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ 2174399e0cfSBrian Gerst __X64_SYS_STUBx(x, name, __VA_ARGS__) \ 218c76fc982SDominik Brodowski __IA32_SYS_STUBx(x, name, __VA_ARGS__) \ 219e145242eSDominik Brodowski static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ 220fa697140SDominik Brodowski { \ 221e145242eSDominik Brodowski long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\ 222fa697140SDominik Brodowski __MAP(x,__SC_TEST,__VA_ARGS__); \ 223fa697140SDominik Brodowski __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \ 224fa697140SDominik Brodowski return ret; \ 225fa697140SDominik Brodowski } \ 226e145242eSDominik Brodowski static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) 227fa697140SDominik Brodowski 228fa697140SDominik Brodowski /* 229d5a00528SDominik Brodowski * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for 230d5a00528SDominik Brodowski * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not 231d5a00528SDominik Brodowski * hurt, we only need to re-define it here to keep the naming congruent to 232d5a00528SDominik Brodowski * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() and SYS_NI() 233d5a00528SDominik Brodowski * macros to work correctly. 234d5a00528SDominik Brodowski */ 235d5a00528SDominik Brodowski #define SYSCALL_DEFINE0(sname) \ 236d5a00528SDominik Brodowski SYSCALL_METADATA(_##sname, 0); \ 237d2b5de49SBrian Gerst static asmlinkage long \ 238d2b5de49SBrian Gerst __do_sys_##sname(const struct pt_regs *__unused); \ 239d2b5de49SBrian Gerst __X64_SYS_STUB0(sname) \ 240d2b5de49SBrian Gerst __IA32_SYS_STUB0(sname) \ 241d2b5de49SBrian Gerst static asmlinkage long \ 242d2b5de49SBrian Gerst __do_sys_##sname(const struct pt_regs *__unused) 243d5a00528SDominik Brodowski 2446e484764SSami Tolvanen #define COND_SYSCALL(name) \ 2456cc8d2b2SBrian Gerst __X64_COND_SYSCALL(name) \ 2466cc8d2b2SBrian Gerst __IA32_COND_SYSCALL(name) 247d5a00528SDominik Brodowski 248a74d187cSBrian Gerst #define SYS_NI(name) \ 249a74d187cSBrian Gerst __X64_SYS_NI(name) \ 250a74d187cSBrian Gerst __IA32_SYS_NI(name) 251d5a00528SDominik Brodowski 252d5a00528SDominik Brodowski 253d5a00528SDominik Brodowski /* 254fa697140SDominik Brodowski * For VSYSCALLS, we need to declare these three syscalls with the new 255fa697140SDominik Brodowski * pt_regs-based calling convention for in-kernel use. 256fa697140SDominik Brodowski */ 257d5a00528SDominik Brodowski asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs); 258d5a00528SDominik Brodowski asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs); 259d5a00528SDominik Brodowski asmlinkage long __x64_sys_time(const struct pt_regs *regs); 260fa697140SDominik Brodowski 261fa697140SDominik Brodowski #endif /* _ASM_X86_SYSCALL_WRAPPER_H */ 262