diff options
Diffstat (limited to 'arch/powerpc/include/asm/syscall.h')
| -rw-r--r-- | arch/powerpc/include/asm/syscall.h | 117 |
1 files changed, 85 insertions, 32 deletions
diff --git a/arch/powerpc/include/asm/syscall.h b/arch/powerpc/include/asm/syscall.h index b54b2add07be..4b3c52ed6e9d 100644 --- a/arch/powerpc/include/asm/syscall.h +++ b/arch/powerpc/include/asm/syscall.h @@ -1,29 +1,52 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Access to user system call parameters and results * * Copyright (C) 2008 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_SYSCALL_H #define _ASM_SYSCALL_H 1 +#include <uapi/linux/audit.h> #include <linux/sched.h> +#include <linux/thread_info.h> + +#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER +typedef long (*syscall_fn)(const struct pt_regs *); +#else +typedef long (*syscall_fn)(unsigned long, unsigned long, unsigned long, + unsigned long, unsigned long, unsigned long); +#endif /* ftrace syscalls requires exporting the sys_call_table */ -#ifdef CONFIG_FTRACE_SYSCALLS -extern const unsigned long *sys_call_table; -#endif /* CONFIG_FTRACE_SYSCALLS */ +extern const syscall_fn sys_call_table[]; +extern const syscall_fn compat_sys_call_table[]; + +static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) +{ + /* + * Note that we are returning an int here. That means 0xffffffff, ie. + * 32-bit negative 1, will be interpreted as -1 on a 64-bit kernel. + * This is important for seccomp so that compat tasks can set r0 = -1 + * to reject the syscall. + */ + if (trap_is_syscall(regs)) + return regs->gpr[0]; + else + return -1; +} -static inline long syscall_get_nr(struct task_struct *task, - struct pt_regs *regs) +static inline void syscall_set_nr(struct task_struct *task, struct pt_regs *regs, int nr) { - return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L; + /* + * Unlike syscall_get_nr(), syscall_set_nr() can be called only when + * the target task is stopped for tracing on entering syscall, so + * there is no need to have the same check syscall_get_nr() has. + */ + regs->gpr[0] = nr; } static inline void syscall_rollback(struct task_struct *task, @@ -35,7 +58,17 @@ static inline void syscall_rollback(struct task_struct *task, static inline long syscall_get_error(struct task_struct *task, struct pt_regs *regs) { - return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0; + if (trap_is_scv(regs)) { + unsigned long error = regs->gpr[3]; + + return IS_ERR_VALUE(error) ? error : 0; + } else { + /* + * If the system call failed, + * regs->gpr[3] contains a positive ERRORCODE. + */ + return (regs->ccr & 0x10000000UL) ? -regs->gpr[3] : 0; + } } static inline long syscall_get_return_value(struct task_struct *task, @@ -48,42 +81,62 @@ static inline void syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, int error, long val) { - if (error) { - regs->ccr |= 0x10000000L; - regs->gpr[3] = -error; + if (trap_is_scv(regs)) { + regs->gpr[3] = (long) error ?: val; } else { - regs->ccr &= ~0x10000000L; - regs->gpr[3] = val; + /* + * In the general case it's not obvious that we must deal with + * CCR here, as the syscall exit path will also do that for us. + * However there are some places, eg. the signal code, which + * check ccr to decide if the value in r3 is actually an error. + */ + if (error) { + regs->ccr |= 0x10000000L; + regs->gpr[3] = error; + } else { + regs->ccr &= ~0x10000000L; + regs->gpr[3] = val; + } } } 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); -#ifdef CONFIG_PPC64 - if (test_tsk_thread_flag(task, TIF_32BIT)) { - /* - * Zero-extend 32-bit argument values. The high bits are - * garbage ignored by the actual syscall dispatch. - */ - while (n-- > 0) - args[n] = (u32) regs->gpr[3 + i + n]; - return; + unsigned long val, mask = -1UL; + unsigned int n = 6; + + if (is_tsk_32bit_task(task)) + mask = 0xffffffff; + + while (n--) { + if (n == 0) + val = regs->orig_gpr3; + else + val = regs->gpr[3 + n]; + + args[n] = val & mask; } -#endif - memcpy(args, ®s->gpr[3 + 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->gpr[3 + i], args, n * sizeof(args[0])); + memcpy(®s->gpr[3], args, 6 * sizeof(args[0])); + + /* Also copy the first argument into orig_gpr3 */ + regs->orig_gpr3 = args[0]; } +static inline int syscall_get_arch(struct task_struct *task) +{ + if (is_tsk_32bit_task(task)) + return AUDIT_ARCH_PPC; + else if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN)) + return AUDIT_ARCH_PPC64LE; + else + return AUDIT_ARCH_PPC64; +} #endif /* _ASM_SYSCALL_H */ |