Re: [PATCH 4/8] abg-elf-helpers: move some kernel helpers from abg-dwarf-reader

[Giuliano Procida <gprocida@google.com>]

Hi.

On Mon, 20 Apr 2020 at 15:32, Giuliano Procida <gprocida@google.com> wrote:
>
> On Mon, 20 Apr 2020 at 12:09, Matthias Maennich <maennich@google.com> wrote:
> >
> > Move some definitions from abg-dwarf-reader to abg-elf-helpers that are
> > strictly only related to ELF.
> >
> >         * abg-dwarf-reader.cc(binary_is_linux_kernel): Move function out.
> >         (binary_is_linux_kernel_module): Likewise.
> >         (find_ksymtab_strings_section): Likewise.
> >         * abg-elf-helpers.cc(binary_is_linux_kernel): Move function in.
> >         (binary_is_linux_kernel_module): Likewise.
> >         (find_ksymtab_strings_section): Likewise.
>
> Next one should be .h.

But otherwise,
Reviewed-by: Giuliano Procida <gprocida@google.com>

> >         * abg-elf-helpers.cc(binary_is_linux_kernel): Add declaration.
> >         (binary_is_linux_kernel_module): Likewise.
> >         (find_ksymtab_strings_section): Likewise.
> >
> > Signed-off-by: Matthias Maennich <maennich@google.com>
> > ---
> >  src/abg-dwarf-reader.cc | 46 -----------------------------------------
> >  src/abg-elf-helpers.cc  | 45 ++++++++++++++++++++++++++++++++++++++++
> >  src/abg-elf-helpers.h   | 14 +++++++++++++
> >  3 files changed, 59 insertions(+), 46 deletions(-)
> >
> > diff --git a/src/abg-dwarf-reader.cc b/src/abg-dwarf-reader.cc
> > index 303c1f8df4c2..3adb978b784b 100644
> > --- a/src/abg-dwarf-reader.cc
> > +++ b/src/abg-dwarf-reader.cc
> > @@ -542,52 +542,6 @@ compare_dies(const read_context& ctxt,
> >              bool update_canonical_dies_on_the_fly);
> >
> >
> > -/// Test if the ELF binary denoted by a given ELF handle is a Linux
> > -/// Kernel Module.
> > -///
> > -/// @param elf_handle the ELF handle to consider.
> > -///
> > -/// @return true iff the binary denoted by @p elf_handle is a Linux
> > -/// kernel module.
> > -static bool
> > -binary_is_linux_kernel_module(Elf *elf_handle)
> > -{
> > -  return (find_section(elf_handle, ".modinfo", SHT_PROGBITS)
> > -         && find_section(elf_handle,
> > -                         ".gnu.linkonce.this_module",
> > -                         SHT_PROGBITS));
> > -}
> > -
> > -/// Test if the ELF binary denoted by a given ELF handle is a Linux
> > -/// Kernel binary (either vmlinux or a kernel module).
> > -///
> > -/// @param elf_handle the ELF handle to consider.
> > -///
> > -/// @return true iff the binary denoted by @p elf_handle is a Linux
> > -/// kernel binary
> > -static bool
> > -binary_is_linux_kernel(Elf *elf_handle)
> > -{
> > -  return (find_section(elf_handle,
> > -                      "__ksymtab_strings",
> > -                      SHT_PROGBITS)
> > -         || binary_is_linux_kernel_module(elf_handle));
> > -}
> > -
> > -/// Find the __ksymtab_strings section of a Linux kernel binary.
> > -///
> > -///
> > -/// @return the find_ksymtab_strings_section of the linux kernel
> > -/// binary denoted by @p elf_handle, or nil if such a section could
> > -/// not be found.
> > -static Elf_Scn*
> > -find_ksymtab_strings_section(Elf *elf_handle)
> > -{
> > -  if (binary_is_linux_kernel(elf_handle))
> > -    return find_section(elf_handle, "__ksymtab_strings", SHT_PROGBITS);
> > -  return 0;
> > -}
> > -
> >  /// Get the address at which a given binary is loaded in memory⋅
> >  ///
> >  /// @param elf_handle the elf handle for the binary to consider.
> > diff --git a/src/abg-elf-helpers.cc b/src/abg-elf-helpers.cc
> > index b7b868a332ec..ff0941dc6536 100644
> > --- a/src/abg-elf-helpers.cc
> > +++ b/src/abg-elf-helpers.cc
> > @@ -548,6 +548,21 @@ get_symbol_versionning_sections(Elf*               elf_handle,
> >    return false;
> >  }
> >
> > +/// Find the __ksymtab_strings section of a Linux kernel binary.
> > +///
> > +/// @param elf_handle the elf handle to use.
> > +///
> > +/// @return the find_ksymtab_strings_section of the linux kernel
> > +/// binary denoted by @p elf_handle, or nil if such a section could
> > +/// not be found.
> > +Elf_Scn*
> > +find_ksymtab_strings_section(Elf *elf_handle)
> > +{
> > +  if (binary_is_linux_kernel(elf_handle))
> > +    return find_section(elf_handle, "__ksymtab_strings", SHT_PROGBITS);
> > +  return 0;
> > +}
> > +
> >  /// Get the version definition (from the SHT_GNU_verdef section) of a
> >  /// given symbol represented by a pointer to GElf_Versym.
> >  ///
> > @@ -750,7 +765,37 @@ get_version_for_symbol(Elf*                        elf_handle,
> >    return false;
> >  }
> >
> > +/// Test if the ELF binary denoted by a given ELF handle is a Linux
> > +/// Kernel Module.
> > +///
> > +/// @param elf_handle the ELF handle to consider.
> > +///
> > +/// @return true iff the binary denoted by @p elf_handle is a Linux
> > +/// kernel module.
> > +bool
> > +binary_is_linux_kernel_module(Elf *elf_handle)
> > +{
> > +  return (find_section(elf_handle, ".modinfo", SHT_PROGBITS)
> > +         && find_section(elf_handle,
> > +                         ".gnu.linkonce.this_module",
> > +                         SHT_PROGBITS));
> > +}
> >
> > +/// Test if the ELF binary denoted by a given ELF handle is a Linux
> > +/// Kernel binary (either vmlinux or a kernel module).
> > +///
> > +/// @param elf_handle the ELF handle to consider.
> > +///
> > +/// @return true iff the binary denoted by @p elf_handle is a Linux
> > +/// kernel binary
> > +bool
> > +binary_is_linux_kernel(Elf *elf_handle)
> > +{
> > +  return (find_section(elf_handle,
> > +                      "__ksymtab_strings",
> > +                      SHT_PROGBITS)
> > +         || binary_is_linux_kernel_module(elf_handle));
> > +}
> >
> >  } // end namespace elf_helpers
> >  } // end namespace abigail
> > diff --git a/src/abg-elf-helpers.h b/src/abg-elf-helpers.h
> > index 7e1c231ccc4e..33348126028c 100644
> > --- a/src/abg-elf-helpers.h
> > +++ b/src/abg-elf-helpers.h
> > @@ -102,6 +102,9 @@ get_symbol_versionning_sections(Elf*                elf_handle,
> >                                 Elf_Scn*&       verdef_section,
> >                                 Elf_Scn*&       verneed_section);
> >
> > +Elf_Scn*
> > +find_ksymtab_strings_section(Elf *elf_handle);
> > +
> >  //
> >  // Helpers for symbol versioning
> >  //
> > @@ -124,6 +127,17 @@ get_version_for_symbol(Elf*                        elf_handle,
> >                        bool                     get_def_version,
> >                        elf_symbol::version&     version);
> >
> > +//
> > +// Helpers for Linux Kernel Binaries
> > +//
> > +
> > +bool
> > +binary_is_linux_kernel_module(Elf *elf_handle);
> > +
> > +bool
> > +binary_is_linux_kernel(Elf *elf_handle);
> > +
> > +
> >  } // end namespace elf_helpers
> >  } // end namespace abigail
> >
> > --
> > 2.26.1.301.g55bc3eb7cb9-goog
> >