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   execstack    ( 8 )

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Имя (Name)

execstack - tool to set, clear, or query executable stack flag of
       ELF binaries and shared libraries

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Синопсис (Synopsis)

execstack [OPTION...] [FILES]

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Описание (Description)

execstack is a program which sets, clears, or queries executable
       stack flag of ELF binaries and shared libraries.  Linux has in
       the past allowed execution of instructions on the stack and there
       are lots of binaries and shared libraries assuming this
       behaviour.  Furthermore, GCC trampoline code for e.g. nested
       functions requires executable stack on many architectures.  To
       avoid breaking binaries and shared libraries which need
       executable stack, ELF binaries and shared libraries now can be
       marked as requiring executable stack or not requiring it.  This
       marking is done through the p_flags field in the PT_GNU_STACK
       program header entry.  If the marking is missing, kernel or
       dynamic linker need to assume it might need executable stack.
       The marking is done automatically by recent GCC versions (objects
       using trampolines on the stack are marked as requiring executable
       stack, all other newly built objects are marked as not requiring
       it) and linker collects these markings into marking of the whole
       binary or shared library.  The user can override this at assembly
       time (through --execstack or --noexecstack assembler options), at
       link time (through -z execstack or -z noexecstack linker options)
       and using the execstack tool also on an already linker binary or
       shared library.  This tool is especially useful for third party
       shared libraries where it is known that they don't need
       executable stack or testing proves it.

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Параметры (Options)

-s --set-execstack
              Mark binary or shared library as requiring executable
              stack.

       -c --clear-execstack
              Mark binary or shared library as not requiring executable
              stack.

       -q --query
              Query executable stack marking of binaries and shared
              libraries.  For each file it prints either - when
              executable stack is not required, X when executable stack
              is required or ?  when it is unknown whether the object
              requires or doesn't require executable stack (the marking
              is missing).

       -V     Print execstack version and exit.

       -? --help
              Print help message.

       --usage
              Print a short usage message.

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Аргументы (Arguments)

Command line arguments should be names of ELF binaries and shared
       libraries which should be modified or queried.

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Примеры (Examples)

# execstack -s ~/lib/libfoo.so.1
       will mark ~/lib/libfoo.so.1 as requiring executable stack.
              # execstack -c ~/bin/bar
       will mark ~/bin/bar as not requiring executable stack.
              # execstack -q ~/lib/libfoo.so.1 ~/bin/bar
       will query executable stack marking of the given files.

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Смотри также (See also)

ld.so(8).

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Ошибки (баги) (Bugs)

execstack doesn't support yet marking of executables if they do
       not have PT_GNU_STACK program header entry nor they have room for
       program segment header table growth.

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