Add subarchitecture-independent implementation of asm-generic/syscall.h allowing access to user system call parameters and results: * syscall_get_nr() * syscall_rollback() * syscall_get_error() * syscall_get_return_value() * syscall_set_return_value() * syscall_get_arguments() * syscall_set_arguments() * syscall_get_arch() provided by arch/x86/um/asm/syscall.h This provides the necessary syscall helpers needed by HAVE_ARCH_SECCOMP_FILTER plus syscall_get_error(). This is inspired from Meredydd Luff's patch (https://gerrit.chromium.org/gerrit/21425). Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx> Cc: Jeff Dike <jdike@xxxxxxxxxxx> Cc: Richard Weinberger <richard@xxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: x86@xxxxxxxxxx Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Will Drewry <wad@xxxxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: user-mode-linux-devel@xxxxxxxxxxxxxxxxxxxxx Cc: user-mode-linux-user@xxxxxxxxxxxxxxxxxxxxx Cc: Meredydd Luff <meredydd@xxxxxxxxxxxxxxx> Cc: David Drysdale <drysdale@xxxxxxxxxx> --- arch/um/include/asm/syscall-generic.h | 138 ++++++++++++++++++++++++++++++++++ arch/x86/um/asm/syscall.h | 1 + 2 files changed, 139 insertions(+) create mode 100644 arch/um/include/asm/syscall-generic.h diff --git a/arch/um/include/asm/syscall-generic.h b/arch/um/include/asm/syscall-generic.h new file mode 100644 index 0000000..9fb9cf8 --- /dev/null +++ b/arch/um/include/asm/syscall-generic.h @@ -0,0 +1,138 @@ +/* + * Access to user system call parameters and results + * + * See asm-generic/syscall.h for function descriptions. + * + * Copyright (C) 2015 Mickaël Salaün <mic@xxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __UM_SYSCALL_GENERIC_H +#define __UM_SYSCALL_GENERIC_H + +#include <asm/ptrace.h> +#include <linux/err.h> +#include <linux/sched.h> +#include <sysdep/ptrace.h> + +static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) +{ + + return PT_REGS_SYSCALL_NR(regs); +} + +static inline void syscall_rollback(struct task_struct *task, + struct pt_regs *regs) +{ + /* do nothing */ +} + +static inline long syscall_get_error(struct task_struct *task, + struct pt_regs *regs) +{ + const long error = regs_return_value(regs); + + return IS_ERR_VALUE(error) ? error : 0; +} + +static inline long syscall_get_return_value(struct task_struct *task, + struct pt_regs *regs) +{ + return regs_return_value(regs); +} + +static inline void syscall_set_return_value(struct task_struct *task, + struct pt_regs *regs, + int error, long val) +{ + PT_REGS_SET_SYSCALL_RETURN(regs, (long) error ?: val); +} + +static inline void syscall_get_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + unsigned long *args) +{ + const struct uml_pt_regs *r = ®s->regs; + + switch (i) { + case 0: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG1(r); + case 1: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG2(r); + case 2: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG3(r); + case 3: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG4(r); + case 4: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG5(r); + case 5: + if (!n--) + break; + *args++ = UPT_SYSCALL_ARG6(r); + 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) +{ + struct uml_pt_regs *r = ®s->regs; + + switch (i) { + case 0: + if (!n--) + break; + UPT_SYSCALL_ARG1(r) = *args++; + case 1: + if (!n--) + break; + UPT_SYSCALL_ARG2(r) = *args++; + case 2: + if (!n--) + break; + UPT_SYSCALL_ARG3(r) = *args++; + case 3: + if (!n--) + break; + UPT_SYSCALL_ARG4(r) = *args++; + case 4: + if (!n--) + break; + UPT_SYSCALL_ARG5(r) = *args++; + case 5: + if (!n--) + break; + UPT_SYSCALL_ARG6(r) = *args++; + case 6: + if (!n--) + break; + default: + BUG(); + break; + } +} + +/* See arch/x86/um/asm/syscall.h for syscall_get_arch() definition. */ + +#endif /* __UM_SYSCALL_GENERIC_H */ diff --git a/arch/x86/um/asm/syscall.h b/arch/x86/um/asm/syscall.h index 81d6562..11ab90d 100644 --- a/arch/x86/um/asm/syscall.h +++ b/arch/x86/um/asm/syscall.h @@ -1,6 +1,7 @@ #ifndef __UM_ASM_SYSCALL_H #define __UM_ASM_SYSCALL_H +#include <asm/syscall-generic.h> #include <uapi/linux/audit.h> typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, -- 2.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
