| Message ID | 11d0aa3cb1c97a02853bc9b1a68f4f64fb4a5c13.1660903960.git.fweimer@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Check ld.so/libc.so consistency during startup | expand |
On 8/19/22 06:16, Florian Weimer via Libc-alpha wrote: > ELF and GNU hashes can now be computed using the elf_hash and > gnu_hash functions. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com> > --- > elf/tst-glibcelf.py | 19 +++++++++++++++++++ > scripts/glibcelf.py | 19 +++++++++++++++++++ > 2 files changed, 38 insertions(+) > > diff --git a/elf/tst-glibcelf.py b/elf/tst-glibcelf.py > index bf15a3bad4..e5026e2289 100644 > --- a/elf/tst-glibcelf.py > +++ b/elf/tst-glibcelf.py > @@ -240,6 +240,24 @@ def check_constant_values(cc): > error('{}: glibcelf has {!r}, <elf.h> has {!r}'.format( > name, glibcelf_value, elf_h_value)) > > +def check_hashes(): > + for name, expected_elf, expected_gnu in ( > + ('', 0, 0x1505), > + ('PPPPPPPPPPPP', 0, 0x9f105c45), > + ('GLIBC_2.0', 0xd696910, 0xf66c3dd5), > + ('GLIBC_2.34', 0x69691b4, 0xc3f3f90c), > + ('GLIBC_PRIVATE', 0x963cf85, 0x692a260)): > + for convert in (lambda x: x, lambda x: x.encode('UTF-8')): > + name = convert(name) > + actual_elf = glibcelf.elf_hash(name) > + if actual_elf != expected_elf: > + error('elf_hash({!r}): {:x} != 0x{:x}'.format( > + name, actual_elf, expected_elf)) > + actual_gnu = glibcelf.gnu_hash(name) > + if actual_gnu != expected_gnu: > + error('gnu_hash({!r}): {:x} != 0x{:x}'.format( > + name, actual_gnu, expected_gnu)) > + > def main(): > """The main entry point.""" > parser = argparse.ArgumentParser( > @@ -251,6 +269,7 @@ def main(): > check_duplicates() > check_constant_prefixes() > check_constant_values(cc=args.cc) > + check_hashes() > > if errors_encountered > 0: > print("note: errors encountered:", errors_encountered) > diff --git a/scripts/glibcelf.py b/scripts/glibcelf.py > index de0509130e..5c8f46f590 100644 > --- a/scripts/glibcelf.py > +++ b/scripts/glibcelf.py > @@ -1158,5 +1158,24 @@ class Image: > self._stringtab[sh_link] = strtab > return strtab > > +def elf_hash(s): > + """Computes the ELF hash of the string.""" > + acc = 0 > + for ch in s: > + if type(ch) is not int: > + ch = ord(ch) > + acc = ((acc << 4) + ch) & 0xffffffff > + top = acc & 0xf0000000 > + acc = (acc ^ (top >> 24)) & ~top > + return acc > + > +def gnu_hash(s): > + """Computes the GNU hash of the string.""" > + h = 5381 > + for ch in s: > + if type(ch) is not int: > + ch = ord(ch) > + h = (h * 33 + ch) & 0xffffffff > + return h > > __all__ = [name for name in dir() if name[0].isupper()]
* Carlos O'Donell: > On 8/19/22 06:16, Florian Weimer via Libc-alpha wrote: >> ELF and GNU hashes can now be computed using the elf_hash and >> gnu_hash functions. > > Reviewed-by: Carlos O'Donell <carlos@redhat.com> > Tested-by: Carlos O'Donell <carlos@redhat.com> I've pushed this separately. Thanks, Florian
diff --git a/elf/tst-glibcelf.py b/elf/tst-glibcelf.py index bf15a3bad4..e5026e2289 100644 --- a/elf/tst-glibcelf.py +++ b/elf/tst-glibcelf.py @@ -240,6 +240,24 @@ def check_constant_values(cc): error('{}: glibcelf has {!r}, <elf.h> has {!r}'.format( name, glibcelf_value, elf_h_value)) +def check_hashes(): + for name, expected_elf, expected_gnu in ( + ('', 0, 0x1505), + ('PPPPPPPPPPPP', 0, 0x9f105c45), + ('GLIBC_2.0', 0xd696910, 0xf66c3dd5), + ('GLIBC_2.34', 0x69691b4, 0xc3f3f90c), + ('GLIBC_PRIVATE', 0x963cf85, 0x692a260)): + for convert in (lambda x: x, lambda x: x.encode('UTF-8')): + name = convert(name) + actual_elf = glibcelf.elf_hash(name) + if actual_elf != expected_elf: + error('elf_hash({!r}): {:x} != 0x{:x}'.format( + name, actual_elf, expected_elf)) + actual_gnu = glibcelf.gnu_hash(name) + if actual_gnu != expected_gnu: + error('gnu_hash({!r}): {:x} != 0x{:x}'.format( + name, actual_gnu, expected_gnu)) + def main(): """The main entry point.""" parser = argparse.ArgumentParser( @@ -251,6 +269,7 @@ def main(): check_duplicates() check_constant_prefixes() check_constant_values(cc=args.cc) + check_hashes() if errors_encountered > 0: print("note: errors encountered:", errors_encountered) diff --git a/scripts/glibcelf.py b/scripts/glibcelf.py index de0509130e..5c8f46f590 100644 --- a/scripts/glibcelf.py +++ b/scripts/glibcelf.py @@ -1158,5 +1158,24 @@ class Image: self._stringtab[sh_link] = strtab return strtab +def elf_hash(s): + """Computes the ELF hash of the string.""" + acc = 0 + for ch in s: + if type(ch) is not int: + ch = ord(ch) + acc = ((acc << 4) + ch) & 0xffffffff + top = acc & 0xf0000000 + acc = (acc ^ (top >> 24)) & ~top + return acc + +def gnu_hash(s): + """Computes the GNU hash of the string.""" + h = 5381 + for ch in s: + if type(ch) is not int: + ch = ord(ch) + h = (h * 33 + ch) & 0xffffffff + return h __all__ = [name for name in dir() if name[0].isupper()]