diff options
Diffstat (limited to 'kernel/arch/x86/include/asm/syscall.h')
| -rw-r--r-- | kernel/arch/x86/include/asm/syscall.h | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/kernel/arch/x86/include/asm/syscall.h b/kernel/arch/x86/include/asm/syscall.h new file mode 100644 index 000000000..d6a756ae0 --- /dev/null +++ b/kernel/arch/x86/include/asm/syscall.h @@ -0,0 +1,243 @@ +/* + * Access to user system call parameters and results + * + * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. + * + * This copyrighted material is made available to anyone wishing to use, + * modify, copy, or redistribute it subject to the terms and conditions + * of the GNU General Public License v.2. + * + * See asm-generic/syscall.h for descriptions of what we must do here. + */ + +#ifndef _ASM_X86_SYSCALL_H +#define _ASM_X86_SYSCALL_H + +#include <uapi/linux/audit.h> +#include <linux/sched.h> +#include <linux/err.h> +#include <asm/asm-offsets.h> /* For NR_syscalls */ +#include <asm/thread_info.h> /* for TS_COMPAT */ +#include <asm/unistd.h> + +typedef void (*sys_call_ptr_t)(void); +extern const sys_call_ptr_t sys_call_table[]; + +/* + * Only the low 32 bits of orig_ax are meaningful, so we return int. + * This importantly ignores the high bits on 64-bit, so comparisons + * sign-extend the low 32 bits. + */ +static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) +{ + return regs->orig_ax; +} + +static inline void syscall_rollback(struct task_struct *task, + struct pt_regs *regs) +{ + regs->ax = regs->orig_ax; +} + +static inline long syscall_get_error(struct task_struct *task, + struct pt_regs *regs) +{ + unsigned long error = regs->ax; +#ifdef CONFIG_IA32_EMULATION + /* + * TS_COMPAT is set for 32-bit syscall entries and then + * remains set until we return to user mode. + */ + if (task_thread_info(task)->status & TS_COMPAT) + /* + * Sign-extend the value so (int)-EFOO becomes (long)-EFOO + * and will match correctly in comparisons. + */ + error = (long) (int) error; +#endif + return IS_ERR_VALUE(error) ? error : 0; +} + +static inline long syscall_get_return_value(struct task_struct *task, + struct pt_regs *regs) +{ + return regs->ax; +} + +static inline void syscall_set_return_value(struct task_struct *task, + struct pt_regs *regs, + int error, long val) +{ + regs->ax = (long) error ?: val; +} + +#ifdef CONFIG_X86_32 + +static inline void syscall_get_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + unsigned long *args) +{ + BUG_ON(i + n > 6); + memcpy(args, ®s->bx + i, n * sizeof(args[0])); +} + +static inline void syscall_set_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + const unsigned long *args) +{ + BUG_ON(i + n > 6); + memcpy(®s->bx + i, args, n * sizeof(args[0])); +} + +static inline int syscall_get_arch(void) +{ + return AUDIT_ARCH_I386; +} + +#else /* CONFIG_X86_64 */ + +static inline void syscall_get_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + unsigned long *args) +{ +# ifdef CONFIG_IA32_EMULATION + if (task_thread_info(task)->status & TS_COMPAT) + switch (i) { + case 0: + if (!n--) break; + *args++ = regs->bx; + case 1: + if (!n--) break; + *args++ = regs->cx; + case 2: + if (!n--) break; + *args++ = regs->dx; + case 3: + if (!n--) break; + *args++ = regs->si; + case 4: + if (!n--) break; + *args++ = regs->di; + case 5: + if (!n--) break; + *args++ = regs->bp; + case 6: + if (!n--) break; + default: + BUG(); + break; + } + else +# endif + switch (i) { + case 0: + if (!n--) break; + *args++ = regs->di; + case 1: + if (!n--) break; + *args++ = regs->si; + case 2: + if (!n--) break; + *args++ = regs->dx; + case 3: + if (!n--) break; + *args++ = regs->r10; + case 4: + if (!n--) break; + *args++ = regs->r8; + case 5: + if (!n--) break; + *args++ = regs->r9; + case 6: + if (!n--) break; + default: + BUG(); + break; + } +} + +static inline void syscall_set_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + const unsigned long *args) +{ +# ifdef CONFIG_IA32_EMULATION + if (task_thread_info(task)->status & TS_COMPAT) + switch (i) { + case 0: + if (!n--) break; + regs->bx = *args++; + case 1: + if (!n--) break; + regs->cx = *args++; + case 2: + if (!n--) break; + regs->dx = *args++; + case 3: + if (!n--) break; + regs->si = *args++; + case 4: + if (!n--) break; + regs->di = *args++; + case 5: + if (!n--) break; + regs->bp = *args++; + case 6: + if (!n--) break; + default: + BUG(); + break; + } + else +# endif + switch (i) { + case 0: + if (!n--) break; + regs->di = *args++; + case 1: + if (!n--) break; + regs->si = *args++; + case 2: + if (!n--) break; + regs->dx = *args++; + case 3: + if (!n--) break; + regs->r10 = *args++; + case 4: + if (!n--) break; + regs->r8 = *args++; + case 5: + if (!n--) break; + regs->r9 = *args++; + case 6: + if (!n--) break; + default: + BUG(); + break; + } +} + +static inline int syscall_get_arch(void) +{ +#ifdef CONFIG_IA32_EMULATION + /* + * TS_COMPAT is set for 32-bit syscall entry and then + * remains set until we return to user mode. + * + * TIF_IA32 tasks should always have TS_COMPAT set at + * system call time. + * + * x32 tasks should be considered AUDIT_ARCH_X86_64. + */ + if (task_thread_info(current)->status & TS_COMPAT) + return AUDIT_ARCH_I386; +#endif + /* Both x32 and x86_64 are considered "64-bit". */ + return AUDIT_ARCH_X86_64; +} +#endif /* CONFIG_X86_32 */ + +#endif /* _ASM_X86_SYSCALL_H */ |