forked from luck/tmp_suning_uos_patched
6341c393fc
This moves all the ptrace hooks related to exec into tracehook.h inlines. This also lifts the calls for tracing out of the binfmt load_binary hooks into search_binary_handler() after it calls into the binfmt module. This change has no effect, since all the binfmt modules' load_binary functions did the call at the end on success, and now search_binary_handler() does it immediately after return if successful. We consolidate the repeated code, and binfmt modules no longer need to import ptrace_notify(). Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Reviewed-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
99 lines
3.8 KiB
C
99 lines
3.8 KiB
C
/*
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* Tracing hooks
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*
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* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License v.2.
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*
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* This file defines hook entry points called by core code where
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* user tracing/debugging support might need to do something. These
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* entry points are called tracehook_*(). Each hook declared below
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* has a detailed kerneldoc comment giving the context (locking et
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* al) from which it is called, and the meaning of its return value.
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*
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* Each function here typically has only one call site, so it is ok
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* to have some nontrivial tracehook_*() inlines. In all cases, the
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* fast path when no tracing is enabled should be very short.
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*
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* The purpose of this file and the tracehook_* layer is to consolidate
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* the interface that the kernel core and arch code uses to enable any
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* user debugging or tracing facility (such as ptrace). The interfaces
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* here are carefully documented so that maintainers of core and arch
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* code do not need to think about the implementation details of the
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* tracing facilities. Likewise, maintainers of the tracing code do not
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* need to understand all the calling core or arch code in detail, just
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* documented circumstances of each call, such as locking conditions.
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*
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* If the calling core code changes so that locking is different, then
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* it is ok to change the interface documented here. The maintainer of
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* core code changing should notify the maintainers of the tracing code
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* that they need to work out the change.
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*
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* Some tracehook_*() inlines take arguments that the current tracing
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* implementations might not necessarily use. These function signatures
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* are chosen to pass in all the information that is on hand in the
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* caller and might conceivably be relevant to a tracer, so that the
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* core code won't have to be updated when tracing adds more features.
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* If a call site changes so that some of those parameters are no longer
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* already on hand without extra work, then the tracehook_* interface
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* can change so there is no make-work burden on the core code. The
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* maintainer of core code changing should notify the maintainers of the
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* tracing code that they need to work out the change.
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*/
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#ifndef _LINUX_TRACEHOOK_H
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#define _LINUX_TRACEHOOK_H 1
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#include <linux/sched.h>
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#include <linux/ptrace.h>
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#include <linux/security.h>
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struct linux_binprm;
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/**
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* tracehook_unsafe_exec - check for exec declared unsafe due to tracing
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* @task: current task doing exec
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*
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* Return %LSM_UNSAFE_* bits applied to an exec because of tracing.
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*
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* Called with task_lock() held on @task.
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*/
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static inline int tracehook_unsafe_exec(struct task_struct *task)
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{
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int unsafe = 0;
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int ptrace = task_ptrace(task);
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if (ptrace & PT_PTRACED) {
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if (ptrace & PT_PTRACE_CAP)
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unsafe |= LSM_UNSAFE_PTRACE_CAP;
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else
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unsafe |= LSM_UNSAFE_PTRACE;
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}
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return unsafe;
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}
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/**
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* tracehook_report_exec - a successful exec was completed
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* @fmt: &struct linux_binfmt that performed the exec
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* @bprm: &struct linux_binprm containing exec details
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* @regs: user-mode register state
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*
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* An exec just completed, we are shortly going to return to user mode.
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* The freshly initialized register state can be seen and changed in @regs.
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* The name, file and other pointers in @bprm are still on hand to be
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* inspected, but will be freed as soon as this returns.
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*
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* Called with no locks, but with some kernel resources held live
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* and a reference on @fmt->module.
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*/
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static inline void tracehook_report_exec(struct linux_binfmt *fmt,
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struct linux_binprm *bprm,
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struct pt_regs *regs)
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{
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if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) &&
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unlikely(task_ptrace(current) & PT_PTRACED))
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send_sig(SIGTRAP, current, 0);
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}
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#endif /* <linux/tracehook.h> */
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