10a16997db
RISC-V syscall arguments are located in orig_a0,a1..a5 fields
of struct pt_regs.
Due to an off-by-one bug and a bug in pointer arithmetic
syscall_get_arguments() was reading s3..s7 fields instead of a1..a5.
Likewise, syscall_set_arguments() was writing s3..s7 fields
instead of a1..a5.
Link: http://lkml.kernel.org/r/20190329171221.GA32456@altlinux.org
Fixes: e2c0cdfba7 ("RISC-V: User-facing API")
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Will Drewry <wad@chromium.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Cc: stable@vger.kernel.org # v4.15+
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
115 lines
2.7 KiB
C
115 lines
2.7 KiB
C
/*
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* Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
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* Copyright 2010 Tilera Corporation. All Rights Reserved.
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* Copyright 2015 Regents of the University of California, Berkeley
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* See asm-generic/syscall.h for descriptions of what we must do here.
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*/
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#ifndef _ASM_RISCV_SYSCALL_H
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#define _ASM_RISCV_SYSCALL_H
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#include <uapi/linux/audit.h>
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#include <linux/sched.h>
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#include <linux/err.h>
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/* The array of function pointers for syscalls. */
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extern void *sys_call_table[];
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/*
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* Only the low 32 bits of orig_r0 are meaningful, so we return int.
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* This importantly ignores the high bits on 64-bit, so comparisons
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* sign-extend the low 32 bits.
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*/
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static inline int syscall_get_nr(struct task_struct *task,
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struct pt_regs *regs)
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{
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return regs->a7;
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}
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static inline void syscall_set_nr(struct task_struct *task,
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struct pt_regs *regs,
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int sysno)
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{
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regs->a7 = sysno;
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}
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static inline void syscall_rollback(struct task_struct *task,
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struct pt_regs *regs)
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{
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regs->a0 = regs->orig_a0;
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}
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static inline long syscall_get_error(struct task_struct *task,
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struct pt_regs *regs)
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{
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unsigned long error = regs->a0;
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return IS_ERR_VALUE(error) ? error : 0;
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}
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static inline long syscall_get_return_value(struct task_struct *task,
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struct pt_regs *regs)
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{
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return regs->a0;
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}
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static inline void syscall_set_return_value(struct task_struct *task,
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struct pt_regs *regs,
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int error, long val)
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{
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regs->a0 = (long) error ?: val;
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}
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static inline void syscall_get_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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unsigned long *args)
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{
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BUG_ON(i + n > 6);
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if (i == 0) {
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args[0] = regs->orig_a0;
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args++;
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n--;
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} else {
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i--;
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}
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memcpy(args, ®s->a1 + i, n * sizeof(args[0]));
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}
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static inline void syscall_set_arguments(struct task_struct *task,
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struct pt_regs *regs,
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unsigned int i, unsigned int n,
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const unsigned long *args)
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{
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BUG_ON(i + n > 6);
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if (i == 0) {
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regs->orig_a0 = args[0];
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args++;
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n--;
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} else {
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i--;
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}
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memcpy(®s->a1 + i, args, n * sizeof(regs->a1));
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}
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static inline int syscall_get_arch(void)
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{
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#ifdef CONFIG_64BIT
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return AUDIT_ARCH_RISCV64;
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#else
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return AUDIT_ARCH_RISCV32;
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#endif
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}
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#endif /* _ASM_RISCV_SYSCALL_H */
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