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 11cc42c045SBrian Gerst extern asmlinkage long __x64_sys_ni_syscall(const struct pt_regs *regs); 12cc42c045SBrian Gerst extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs); 13cc42c045SBrian Gerst 14ebeb8c82SDominik Brodowski /* Mapping of registers to parameters for syscalls on x86-64 and x32 */ 15ebeb8c82SDominik Brodowski #define SC_X86_64_REGS_TO_ARGS(x, ...) \ 16ebeb8c82SDominik Brodowski __MAP(x,__SC_ARGS \ 17ebeb8c82SDominik Brodowski ,,regs->di,,regs->si,,regs->dx \ 18ebeb8c82SDominik Brodowski ,,regs->r10,,regs->r8,,regs->r9) \ 19ebeb8c82SDominik Brodowski 20ebeb8c82SDominik Brodowski /* Mapping of registers to parameters for syscalls on i386 */ 21ebeb8c82SDominik Brodowski #define SC_IA32_REGS_TO_ARGS(x, ...) \ 22ebeb8c82SDominik Brodowski __MAP(x,__SC_ARGS \ 23ebeb8c82SDominik Brodowski ,,(unsigned int)regs->bx,,(unsigned int)regs->cx \ 24ebeb8c82SDominik Brodowski ,,(unsigned int)regs->dx,,(unsigned int)regs->si \ 25ebeb8c82SDominik Brodowski ,,(unsigned int)regs->di,,(unsigned int)regs->bp) 26ebeb8c82SDominik Brodowski 27d2b5de49SBrian Gerst #define __SYS_STUB0(abi, name) \ 28d2b5de49SBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs); \ 29d2b5de49SBrian Gerst ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ 30d2b5de49SBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs) \ 31d2b5de49SBrian Gerst __alias(__do_##name); 32d2b5de49SBrian Gerst 334399e0cfSBrian Gerst #define __SYS_STUBx(abi, name, ...) \ 344399e0cfSBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs); \ 354399e0cfSBrian Gerst ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO); \ 364399e0cfSBrian Gerst asmlinkage long __##abi##_##name(const struct pt_regs *regs) \ 374399e0cfSBrian Gerst { \ 384399e0cfSBrian Gerst return __se_##name(__VA_ARGS__); \ 394399e0cfSBrian Gerst } 404399e0cfSBrian Gerst 416cc8d2b2SBrian Gerst #define __COND_SYSCALL(abi, name) \ 426cc8d2b2SBrian Gerst asmlinkage __weak long \ 436cc8d2b2SBrian Gerst __##abi##_##name(const struct pt_regs *__unused) \ 446cc8d2b2SBrian Gerst { \ 456cc8d2b2SBrian Gerst return sys_ni_syscall(); \ 466cc8d2b2SBrian Gerst } 476cc8d2b2SBrian Gerst 48a74d187cSBrian Gerst #define __SYS_NI(abi, name) \ 49a74d187cSBrian Gerst SYSCALL_ALIAS(__##abi##_##name, sys_ni_posix_timers) 50a74d187cSBrian Gerst 514399e0cfSBrian Gerst #ifdef CONFIG_X86_64 52d2b5de49SBrian Gerst #define __X64_SYS_STUB0(name) \ 53d2b5de49SBrian Gerst __SYS_STUB0(x64, sys_##name) 54d2b5de49SBrian Gerst 554399e0cfSBrian Gerst #define __X64_SYS_STUBx(x, name, ...) \ 564399e0cfSBrian Gerst __SYS_STUBx(x64, sys##name, \ 574399e0cfSBrian Gerst SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__)) 586cc8d2b2SBrian Gerst 596cc8d2b2SBrian Gerst #define __X64_COND_SYSCALL(name) \ 606cc8d2b2SBrian Gerst __COND_SYSCALL(x64, sys_##name) 61a74d187cSBrian Gerst 62a74d187cSBrian Gerst #define __X64_SYS_NI(name) \ 63a74d187cSBrian Gerst __SYS_NI(x64, sys_##name) 644399e0cfSBrian Gerst #else /* CONFIG_X86_64 */ 65d2b5de49SBrian Gerst #define __X64_SYS_STUB0(name) 664399e0cfSBrian Gerst #define __X64_SYS_STUBx(x, name, ...) 676cc8d2b2SBrian Gerst #define __X64_COND_SYSCALL(name) 68a74d187cSBrian Gerst #define __X64_SYS_NI(name) 694399e0cfSBrian Gerst #endif /* CONFIG_X86_64 */ 704399e0cfSBrian Gerst 71ebeb8c82SDominik Brodowski #ifdef CONFIG_IA32_EMULATION 72ebeb8c82SDominik Brodowski /* 73ebeb8c82SDominik Brodowski * For IA32 emulation, we need to handle "compat" syscalls *and* create 74e145242eSDominik Brodowski * additional wrappers (aptly named __ia32_sys_xyzzy) which decode the 75ebeb8c82SDominik Brodowski * ia32 regs in the proper order for shared or "common" syscalls. As some 76ebeb8c82SDominik Brodowski * syscalls may not be implemented, we need to expand COND_SYSCALL in 77ebeb8c82SDominik Brodowski * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this 78ebeb8c82SDominik Brodowski * case as well. 79ebeb8c82SDominik Brodowski */ 80d2b5de49SBrian Gerst #define __IA32_COMPAT_SYS_STUB0(name) \ 81d2b5de49SBrian Gerst __SYS_STUB0(ia32, compat_sys_##name) 82cf3b83e1SAndy Lutomirski 83c76fc982SDominik Brodowski #define __IA32_COMPAT_SYS_STUBx(x, name, ...) \ 844399e0cfSBrian Gerst __SYS_STUBx(ia32, compat_sys##name, \ 854399e0cfSBrian Gerst SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__)) 86ebeb8c82SDominik Brodowski 876cc8d2b2SBrian Gerst #define __IA32_COMPAT_COND_SYSCALL(name) \ 886cc8d2b2SBrian Gerst __COND_SYSCALL(ia32, compat_sys_##name) 896cc8d2b2SBrian Gerst 90a74d187cSBrian Gerst #define __IA32_COMPAT_SYS_NI(name) \ 91a74d187cSBrian Gerst __SYS_NI(ia32, compat_sys_##name) 92a74d187cSBrian Gerst 93d2b5de49SBrian Gerst #define __IA32_SYS_STUB0(name) \ 94d2b5de49SBrian Gerst __SYS_STUB0(ia32, sys_##name) 95d2b5de49SBrian Gerst 96c76fc982SDominik Brodowski #define __IA32_SYS_STUBx(x, name, ...) \ 974399e0cfSBrian Gerst __SYS_STUBx(ia32, sys##name, \ 984399e0cfSBrian Gerst SC_IA32_REGS_TO_ARGS(x, __VA_ARGS__)) 99ebeb8c82SDominik Brodowski 1006cc8d2b2SBrian Gerst #define __IA32_COND_SYSCALL(name) \ 1016cc8d2b2SBrian Gerst __COND_SYSCALL(ia32, sys_##name) 102ebeb8c82SDominik Brodowski 103a74d187cSBrian Gerst #define __IA32_SYS_NI(name) \ 104a74d187cSBrian Gerst __SYS_NI(ia32, sys_##name) 105ebeb8c82SDominik Brodowski #else /* CONFIG_IA32_EMULATION */ 106d2b5de49SBrian Gerst #define __IA32_COMPAT_SYS_STUB0(name) 107c76fc982SDominik Brodowski #define __IA32_COMPAT_SYS_STUBx(x, name, ...) 1086cc8d2b2SBrian Gerst #define __IA32_COMPAT_COND_SYSCALL(name) 109a74d187cSBrian Gerst #define __IA32_COMPAT_SYS_NI(name) 110d2b5de49SBrian Gerst #define __IA32_SYS_STUB0(name) 1114399e0cfSBrian Gerst #define __IA32_SYS_STUBx(x, name, ...) 1126cc8d2b2SBrian Gerst #define __IA32_COND_SYSCALL(name) 113a74d187cSBrian Gerst #define __IA32_SYS_NI(name) 114ebeb8c82SDominik Brodowski #endif /* CONFIG_IA32_EMULATION */ 115ebeb8c82SDominik Brodowski 116ebeb8c82SDominik Brodowski 117ebeb8c82SDominik Brodowski #ifdef CONFIG_X86_X32 118ebeb8c82SDominik Brodowski /* 119ebeb8c82SDominik Brodowski * For the x32 ABI, we need to create a stub for compat_sys_*() which is aware 120ebeb8c82SDominik Brodowski * of the x86-64-style parameter ordering of x32 syscalls. The syscalls common 121ebeb8c82SDominik Brodowski * with x86_64 obviously do not need such care. 122ebeb8c82SDominik Brodowski */ 123d2b5de49SBrian Gerst #define __X32_COMPAT_SYS_STUB0(name) \ 124d2b5de49SBrian Gerst __SYS_STUB0(x32, compat_sys_##name) 125cf3b83e1SAndy Lutomirski 126c76fc982SDominik Brodowski #define __X32_COMPAT_SYS_STUBx(x, name, ...) \ 1274399e0cfSBrian Gerst __SYS_STUBx(x32, compat_sys##name, \ 1284399e0cfSBrian Gerst SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__)) 129ebeb8c82SDominik Brodowski 1306cc8d2b2SBrian Gerst #define __X32_COMPAT_COND_SYSCALL(name) \ 1316cc8d2b2SBrian Gerst __COND_SYSCALL(x32, compat_sys_##name) 132a74d187cSBrian Gerst 133a74d187cSBrian Gerst #define __X32_COMPAT_SYS_NI(name) \ 134a74d187cSBrian Gerst __SYS_NI(x32, compat_sys_##name) 135ebeb8c82SDominik Brodowski #else /* CONFIG_X86_X32 */ 136d2b5de49SBrian Gerst #define __X32_COMPAT_SYS_STUB0(name) 137c76fc982SDominik Brodowski #define __X32_COMPAT_SYS_STUBx(x, name, ...) 1386cc8d2b2SBrian Gerst #define __X32_COMPAT_COND_SYSCALL(name) 139a74d187cSBrian Gerst #define __X32_COMPAT_SYS_NI(name) 140ebeb8c82SDominik Brodowski #endif /* CONFIG_X86_X32 */ 141ebeb8c82SDominik Brodowski 142ebeb8c82SDominik Brodowski 143ebeb8c82SDominik Brodowski #ifdef CONFIG_COMPAT 144ebeb8c82SDominik Brodowski /* 145ebeb8c82SDominik Brodowski * Compat means IA32_EMULATION and/or X86_X32. As they use a different 146ebeb8c82SDominik Brodowski * mapping of registers to parameters, we need to generate stubs for each 147d5a00528SDominik Brodowski * of them. 148ebeb8c82SDominik Brodowski */ 149cf3b83e1SAndy Lutomirski #define COMPAT_SYSCALL_DEFINE0(name) \ 150d2b5de49SBrian Gerst static asmlinkage long \ 151d2b5de49SBrian Gerst __do_compat_sys_##name(const struct pt_regs *__unused); \ 152d2b5de49SBrian Gerst __IA32_COMPAT_SYS_STUB0(name) \ 153d2b5de49SBrian Gerst __X32_COMPAT_SYS_STUB0(name) \ 154d2b5de49SBrian Gerst static asmlinkage long \ 155d2b5de49SBrian Gerst __do_compat_sys_##name(const struct pt_regs *__unused) 156cf3b83e1SAndy Lutomirski 157ebeb8c82SDominik Brodowski #define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ 1585ac9efa3SDominik Brodowski static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ 1595ac9efa3SDominik Brodowski static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ 160c76fc982SDominik Brodowski __IA32_COMPAT_SYS_STUBx(x, name, __VA_ARGS__) \ 161c76fc982SDominik Brodowski __X32_COMPAT_SYS_STUBx(x, name, __VA_ARGS__) \ 1625ac9efa3SDominik Brodowski static long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ 163ebeb8c82SDominik Brodowski { \ 1645ac9efa3SDominik Brodowski return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\ 165ebeb8c82SDominik Brodowski } \ 1665ac9efa3SDominik Brodowski static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) 167ebeb8c82SDominik Brodowski 168ebeb8c82SDominik Brodowski /* 169ebeb8c82SDominik Brodowski * As some compat syscalls may not be implemented, we need to expand 170ebeb8c82SDominik Brodowski * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in 171ebeb8c82SDominik Brodowski * kernel/time/posix-stubs.c to cover this case as well. 172ebeb8c82SDominik Brodowski */ 173ebeb8c82SDominik Brodowski #define COND_SYSCALL_COMPAT(name) \ 1746cc8d2b2SBrian Gerst __IA32_COMPAT_COND_SYSCALL(name) \ 1756cc8d2b2SBrian Gerst __X32_COMPAT_COND_SYSCALL(name) 176ebeb8c82SDominik Brodowski 177ebeb8c82SDominik Brodowski #define COMPAT_SYS_NI(name) \ 178a74d187cSBrian Gerst __IA32_COMPAT_SYS_NI(name) \ 179a74d187cSBrian Gerst __X32_COMPAT_SYS_NI(name) 180ebeb8c82SDominik Brodowski 181ebeb8c82SDominik Brodowski #endif /* CONFIG_COMPAT */ 182ebeb8c82SDominik Brodowski 183ebeb8c82SDominik Brodowski 184fa697140SDominik Brodowski /* 185fa697140SDominik Brodowski * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes 186fa697140SDominik Brodowski * struct pt_regs *regs as the only argument of the syscall stub named 187d5a00528SDominik Brodowski * __x64_sys_*(). It decodes just the registers it needs and passes them on to 188e145242eSDominik Brodowski * the __se_sys_*() wrapper performing sign extension and then to the 189e145242eSDominik Brodowski * __do_sys_*() function doing the actual job. These wrappers and functions 190e145242eSDominik Brodowski * are inlined (at least in very most cases), meaning that the assembly looks 191e145242eSDominik Brodowski * as follows (slightly re-ordered for better readability): 192fa697140SDominik Brodowski * 193d5a00528SDominik Brodowski * <__x64_sys_recv>: <-- syscall with 4 parameters 194fa697140SDominik Brodowski * callq <__fentry__> 195fa697140SDominik Brodowski * 196fa697140SDominik Brodowski * mov 0x70(%rdi),%rdi <-- decode regs->di 197fa697140SDominik Brodowski * mov 0x68(%rdi),%rsi <-- decode regs->si 198fa697140SDominik Brodowski * mov 0x60(%rdi),%rdx <-- decode regs->dx 199fa697140SDominik Brodowski * mov 0x38(%rdi),%rcx <-- decode regs->r10 200fa697140SDominik Brodowski * 201fa697140SDominik Brodowski * xor %r9d,%r9d <-- clear %r9 202fa697140SDominik Brodowski * xor %r8d,%r8d <-- clear %r8 203fa697140SDominik Brodowski * 204fa697140SDominik Brodowski * callq __sys_recvfrom <-- do the actual work in __sys_recvfrom() 205fa697140SDominik Brodowski * which takes 6 arguments 206fa697140SDominik Brodowski * 207fa697140SDominik Brodowski * cltq <-- extend return value to 64-bit 208fa697140SDominik Brodowski * retq <-- return 209fa697140SDominik Brodowski * 210fa697140SDominik Brodowski * This approach avoids leaking random user-provided register content down 211fa697140SDominik Brodowski * the call chain. 212fa697140SDominik Brodowski * 213ebeb8c82SDominik Brodowski * If IA32_EMULATION is enabled, this macro generates an additional wrapper 214e145242eSDominik Brodowski * named __ia32_sys_*() which decodes the struct pt_regs *regs according 215ebeb8c82SDominik Brodowski * to the i386 calling convention (bx, cx, dx, si, di, bp). 216fa697140SDominik Brodowski */ 217fa697140SDominik Brodowski #define __SYSCALL_DEFINEx(x, name, ...) \ 218e145242eSDominik Brodowski static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ 219e145242eSDominik Brodowski static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\ 2204399e0cfSBrian Gerst __X64_SYS_STUBx(x, name, __VA_ARGS__) \ 221c76fc982SDominik Brodowski __IA32_SYS_STUBx(x, name, __VA_ARGS__) \ 222e145242eSDominik Brodowski static long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ 223fa697140SDominik Brodowski { \ 224e145242eSDominik Brodowski long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\ 225fa697140SDominik Brodowski __MAP(x,__SC_TEST,__VA_ARGS__); \ 226fa697140SDominik Brodowski __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \ 227fa697140SDominik Brodowski return ret; \ 228fa697140SDominik Brodowski } \ 229e145242eSDominik Brodowski static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) 230fa697140SDominik Brodowski 231fa697140SDominik Brodowski /* 232d5a00528SDominik Brodowski * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for 233d5a00528SDominik Brodowski * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not 234d5a00528SDominik Brodowski * hurt, we only need to re-define it here to keep the naming congruent to 235d5a00528SDominik Brodowski * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() and SYS_NI() 236d5a00528SDominik Brodowski * macros to work correctly. 237d5a00528SDominik Brodowski */ 238d5a00528SDominik Brodowski #define SYSCALL_DEFINE0(sname) \ 239d5a00528SDominik Brodowski SYSCALL_METADATA(_##sname, 0); \ 240d2b5de49SBrian Gerst static asmlinkage long \ 241d2b5de49SBrian Gerst __do_sys_##sname(const struct pt_regs *__unused); \ 242d2b5de49SBrian Gerst __X64_SYS_STUB0(sname) \ 243d2b5de49SBrian Gerst __IA32_SYS_STUB0(sname) \ 244d2b5de49SBrian Gerst static asmlinkage long \ 245d2b5de49SBrian Gerst __do_sys_##sname(const struct pt_regs *__unused) 246d5a00528SDominik Brodowski 2476e484764SSami Tolvanen #define COND_SYSCALL(name) \ 2486cc8d2b2SBrian Gerst __X64_COND_SYSCALL(name) \ 2496cc8d2b2SBrian Gerst __IA32_COND_SYSCALL(name) 250d5a00528SDominik Brodowski 251a74d187cSBrian Gerst #define SYS_NI(name) \ 252a74d187cSBrian Gerst __X64_SYS_NI(name) \ 253a74d187cSBrian Gerst __IA32_SYS_NI(name) 254d5a00528SDominik Brodowski 255d5a00528SDominik Brodowski 256d5a00528SDominik Brodowski /* 257fa697140SDominik Brodowski * For VSYSCALLS, we need to declare these three syscalls with the new 258fa697140SDominik Brodowski * pt_regs-based calling convention for in-kernel use. 259fa697140SDominik Brodowski */ 260d5a00528SDominik Brodowski asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs); 261d5a00528SDominik Brodowski asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs); 262d5a00528SDominik Brodowski asmlinkage long __x64_sys_time(const struct pt_regs *regs); 263fa697140SDominik Brodowski 264fa697140SDominik Brodowski #endif /* _ASM_X86_SYSCALL_WRAPPER_H */ 265