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3e5e7f7736
Reverse the order of arguments to do_syscall_64() so that the first argument is the pt_regs pointer. This is not only consistent with *all* other entry points from assembly, but it actually makes the compiled code slightly better. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20210510185316.3307264-3-hpa@zytor.com
169 lines
4 KiB
C
169 lines
4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Access to user system call parameters and results
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*
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* Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved.
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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_X86_SYSCALL_H
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#define _ASM_X86_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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#include <asm/thread_info.h> /* for TS_COMPAT */
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#include <asm/unistd.h>
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typedef long (*sys_call_ptr_t)(const struct pt_regs *);
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extern const sys_call_ptr_t sys_call_table[];
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#if defined(CONFIG_X86_32)
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#define ia32_sys_call_table sys_call_table
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#endif
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#if defined(CONFIG_IA32_EMULATION)
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extern const sys_call_ptr_t ia32_sys_call_table[];
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#endif
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#ifdef CONFIG_X86_X32_ABI
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extern const sys_call_ptr_t x32_sys_call_table[];
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#endif
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/*
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* Only the low 32 bits of orig_ax 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, struct pt_regs *regs)
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{
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return regs->orig_ax;
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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->ax = regs->orig_ax;
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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->ax;
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#ifdef CONFIG_IA32_EMULATION
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/*
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* TS_COMPAT is set for 32-bit syscall entries and then
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* remains set until we return to user mode.
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*/
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if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED))
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/*
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* Sign-extend the value so (int)-EFOO becomes (long)-EFOO
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* and will match correctly in comparisons.
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*/
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error = (long) (int) error;
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#endif
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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->ax;
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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->ax = (long) error ?: val;
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}
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#ifdef CONFIG_X86_32
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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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memcpy(args, ®s->bx, 6 * 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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memcpy(®s->bx + i, args, n * 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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return AUDIT_ARCH_I386;
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}
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#else /* CONFIG_X86_64 */
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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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# ifdef CONFIG_IA32_EMULATION
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if (task->thread_info.status & TS_COMPAT) {
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*args++ = regs->bx;
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*args++ = regs->cx;
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*args++ = regs->dx;
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*args++ = regs->si;
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*args++ = regs->di;
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*args = regs->bp;
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} else
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# endif
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{
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*args++ = regs->di;
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*args++ = regs->si;
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*args++ = regs->dx;
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*args++ = regs->r10;
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*args++ = regs->r8;
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*args = regs->r9;
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}
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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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const unsigned long *args)
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{
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# ifdef CONFIG_IA32_EMULATION
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if (task->thread_info.status & TS_COMPAT) {
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regs->bx = *args++;
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regs->cx = *args++;
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regs->dx = *args++;
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regs->si = *args++;
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regs->di = *args++;
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regs->bp = *args;
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} else
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# endif
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{
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regs->di = *args++;
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regs->si = *args++;
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regs->dx = *args++;
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regs->r10 = *args++;
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regs->r8 = *args++;
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regs->r9 = *args;
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}
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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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/* x32 tasks should be considered AUDIT_ARCH_X86_64. */
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return (IS_ENABLED(CONFIG_IA32_EMULATION) &&
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task->thread_info.status & TS_COMPAT)
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? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
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}
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void do_syscall_64(struct pt_regs *regs, unsigned long nr);
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void do_int80_syscall_32(struct pt_regs *regs);
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long do_fast_syscall_32(struct pt_regs *regs);
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#endif /* CONFIG_X86_32 */
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#endif /* _ASM_X86_SYSCALL_H */
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