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# link _______________________________________________________
# long sys_link(const char __user * oldname,
# const char __user * newname)
@define _SYSCALL_LINK_NAME
%(
name = "link"
%)
@define _SYSCALL_LINK_ARGSTR
%(
argstr = sprintf("%s, %s", oldpath, newpath)
%)
@define _SYSCALL_LINK_REGARGS
%(
oldpath = user_string_quoted(pointer_arg(1))
oldpath_unquoted = user_string_nofault(pointer_arg(1))
newpath = user_string_quoted(pointer_arg(2))
newpath_unquoted = user_string_nofault(pointer_arg(2))
%)
@define _SYSCALL_LINK_REGARGS_STORE
%(
if (@probewrite(oldpath_unquoted))
set_user_string_arg(pointer_arg(1), oldpath_unquoted)
if (@probewrite(newpath_unquoted))
set_user_string_arg(pointer_arg(2), newpath_unquoted)
%)
probe syscall.link = dw_syscall.link !, nd_syscall.link ? {}
probe syscall.link.return = dw_syscall.link.return !, nd_syscall.link.return ? {}
# dw_link _____________________________________________________
probe dw_syscall.link = kernel.function("sys_link").call
{
@_SYSCALL_LINK_NAME
oldpath = user_string_quoted($oldname)
newpath = user_string_quoted($newname)
@_SYSCALL_LINK_ARGSTR
}
probe dw_syscall.link.return = kernel.function("sys_link").return
{
@_SYSCALL_LINK_NAME
@SYSC_RETVALSTR($return)
}
# nd_link _____________________________________________________
probe nd_syscall.link = nd1_syscall.link!, nd2_syscall.link!, tp_syscall.link
{ }
probe nd1_syscall.link = kprobe.function("sys_link") ?
{
@_SYSCALL_LINK_NAME
asmlinkage()
@_SYSCALL_LINK_REGARGS
@_SYSCALL_LINK_ARGSTR
}
/* kernel 4.17+ */
probe nd2_syscall.link = kprobe.function(@arch_syscall_prefix "sys_link") ?
{
__set_syscall_pt_regs(pointer_arg(1))
@_SYSCALL_LINK_NAME
@_SYSCALL_LINK_REGARGS
@_SYSCALL_LINK_ARGSTR
},
{
%( @_IS_SREG_KERNEL %? @_SYSCALL_LINK_REGARGS_STORE %)
}
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.link = kernel.trace("sys_enter")
{
__set_syscall_pt_regs($regs)
@__syscall_compat_gate(@const("__NR_link"), @const("__NR_compat_link"))
@_SYSCALL_LINK_NAME
@_SYSCALL_LINK_REGARGS
@_SYSCALL_LINK_ARGSTR
},
{
%( @_IS_SREG_KERNEL %? @_SYSCALL_LINK_REGARGS_STORE %)
}
probe nd_syscall.link.return = nd1_syscall.link.return!, nd2_syscall.link.return!, tp_syscall.link.return
{ }
probe nd1_syscall.link.return = kprobe.function("sys_link").return ?
{
@_SYSCALL_LINK_NAME
@SYSC_RETVALSTR(returnval())
}
/* kernel 4.17+ */
probe nd2_syscall.link.return = kprobe.function(@arch_syscall_prefix "sys_link").return ?
{
@_SYSCALL_LINK_NAME
@SYSC_RETVALSTR(returnval())
}
/* kernel 3.5+, but undesirable because it affects all syscalls */
probe tp_syscall.link.return = kernel.trace("sys_exit")
{
__set_syscall_pt_regs($regs)
@__syscall_compat_gate(@const("__NR_link"), @const("__NR_compat_link"))
@_SYSCALL_LINK_NAME
@SYSC_RETVALSTR($ret)
}
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