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4697b5848b
Since commit 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store
thread_info->abi_syscall"), the seccomp selftests "syscall_errno"
and "syscall_faked" have been broken. Both seccomp and PTRACE depend
on using the special value of "-1" for skipping syscalls. This value
wasn't working because it was getting masked by __NR_SYSCALL_MASK in
both PTRACE_SET_SYSCALL and get_syscall_nr().
Explicitly test for -1 in PTRACE_SET_SYSCALL and get_syscall_nr(),
leaving it exposed when present, allowing tracers to skip syscalls
again.
Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Fixes: 4e57a4ddf6b0 ("ARM: 9107/1: syscall: always store thread_info->abi_syscall")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20230810195422.2304827-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
90 lines
2.1 KiB
C
90 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Access to user system call parameters and results
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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_ARM_SYSCALL_H
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#define _ASM_ARM_SYSCALL_H
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#include <uapi/linux/audit.h> /* for AUDIT_ARCH_* */
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#include <linux/elf.h> /* for ELF_EM */
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#include <linux/err.h>
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#include <linux/sched.h>
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#include <asm/unistd.h>
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#define NR_syscalls (__NR_syscalls)
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extern const unsigned long sys_call_table[];
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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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if (IS_ENABLED(CONFIG_AEABI) && !IS_ENABLED(CONFIG_OABI_COMPAT))
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return task_thread_info(task)->abi_syscall;
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if (task_thread_info(task)->abi_syscall == -1)
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return -1;
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return task_thread_info(task)->abi_syscall & __NR_SYSCALL_MASK;
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}
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static inline bool __in_oabi_syscall(struct task_struct *task)
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{
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return IS_ENABLED(CONFIG_OABI_COMPAT) &&
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(task_thread_info(task)->abi_syscall & __NR_OABI_SYSCALL_BASE);
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}
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static inline bool in_oabi_syscall(void)
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{
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return __in_oabi_syscall(current);
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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->ARM_r0 = regs->ARM_ORIG_r0;
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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->ARM_r0;
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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->ARM_r0;
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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->ARM_r0 = (long) error ? error : val;
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}
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#define SYSCALL_MAX_ARGS 7
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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 long *args)
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{
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args[0] = regs->ARM_ORIG_r0;
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args++;
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memcpy(args, ®s->ARM_r0 + 1, 5 * sizeof(args[0]));
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}
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static inline int syscall_get_arch(struct task_struct *task)
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{
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/* ARM tasks don't change audit architectures on the fly. */
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return AUDIT_ARCH_ARM;
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}
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#endif /* _ASM_ARM_SYSCALL_H */
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