Re: [PATCH] elf: Replace tst-p_alignmod1-editX with a python script

["H.J. Lu" <hjl.tools@gmail.com>]

On Wed, Jan 26, 2022 at 7:45 AM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
>
> On 26/01/2022 12:35, H.J. Lu wrote:
> > On Wed, Jan 26, 2022 at 4:10 AM Adhemerval Zanella
> > <adhemerval.zanella@linaro.org> wrote:
> >>
> >>
> >>
> >> On 26/01/2022 07:09, Florian Weimer wrote:
> >>> * Adhemerval Zanella via Libc-alpha:
> >>>
> >>>> diff --git a/scripts/tst-elf-edit.py b/scripts/tst-elf-edit.py
> >>>> new file mode 100644
> >>>> index 0000000000..1fb9b8e0fe
> >>>> --- /dev/null
> >>>> +++ b/scripts/tst-elf-edit.py
> >>>> @@ -0,0 +1,206 @@
> >>>
> >>>> +class Elf_Ehdr:
> >>>> +    def __init__(self, e_ident):
> >>>> +        endian, addr, off = elf_types_fmts(e_ident)
> >>>> +        self.fmt = '{0}HHI{1}{2}{2}IHHHHHH'.format(endian, addr, off)
> >>>> +        self.len = struct.calcsize(self.fmt)
> >>>> +
> >>>> +    def read(self, f):
> >>>> +        buf = f.read(self.len)
> >>>> +        if not buf:
> >>>> +            error('{}: header too small'.format(f.name))
> >>>
> >>> I think you need to check len(buf) < self.len.
> >>
> >> Ack.
> >>
> >>>
> >>>> +class Elf_Phdr:
> >>>> +    def __init__(self, e_ident):
> >>>> +        endian, addr, off = elf_types_fmts(e_ident)
> >>>> +        self.ei_class = e_ident[EI_CLASS]
> >>>> +        if self.ei_class == ELFCLASS32:
> >>>> +            self.fmt = '{0}I{2}{1}{1}IIII'.format(endian, addr, off)
> >>>> +        else:
> >>>> +            self.fmt = '{0}II{2}{1}{1}QQQ'.format(endian, addr, off)
> >>>> +        self.len = struct.calcsize(self.fmt)
> >>>> +
> >>>> +    def read(self, f):
> >>>> +        buf = f.read(self.len)
> >>>> +        if not buf:
> >>>> +            error('{}: program header too small'.format(f.name))
> >>>
> >>> Here as well.
> >>
> >> Ack.
> >>
> >>>
> >>> Rest looks okay.
> >>
> >> Thanks, I push it upstream with the above fixes installed.
> >
> > I got
> >
> > FAIL: elf/tst-p_align3
> >
> > [hjl@gnu-tgl-2 build-x86_64-linux]$ cat elf/tst-p_align3.out
> > /export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/elf/tst-p_align3:
> > error while loading shared libraries:
> > /export/build/gnu/tools-build/glibc-cet-gitlab/build-x86_64-linux/elf/tst-p_alignmod3.so:
> > cannot change memory protections
> > [hjl@gnu-tgl-2 build-x86_64-linux]$
> >
> > Only p_align should be changed to 0x100.  But I  saw
>
> I am not sure if this is related because tst-p_align3 and tst-alignmod3.so uses
> LDFLAGS instead:
>
> 1644 $(objpfx)tst-align3: $(objpfx)tst-alignmod3.so
> 1645 ifeq (yes,$(have-fpie))
> 1646 CFLAGS-tst-align3.c += $(PIE-ccflag)
> 1647 endif
> 1648 LDFLAGS-tst-align3 += -Wl,-z,max-page-size=0x200000
> 1649 LDFLAGS-tst-alignmod3.so += -Wl,-z,max-page-size=0x200000
> 1650 $(objpfx)tst-alignmod3.so: $(libsupport)
>
> And the patch only changed the way tst-p_align1 and tst-p_align2 modules were
> changed.

It is tst-p_alignmod3.so, not tst-alignmod3.so.
            ^^
> >
> > @@ -5,24 +5,24 @@ There are 11 program headers, starting a
> >
> >  Program Headers:
> >    Type           Offset   VirtAddr           PhysAddr
> > FileSiz  MemSiz   Flg Align
> > -  LOAD           0x000000 0x0000000000000000 0x0000000000000000
> > 0x000d38 0x000d38 R   0x200000
> > -  LOAD           0x200000 0x0000000000200000 0x0000000000200000
> > 0x0004c5 0x0004c5 R E 0x200000
> > -  LOAD           0x400000 0x0000000000400000 0x0000000000400000
> > 0x000340 0x000340 R   0x200000
> > -  LOAD           0x400340 0x0000000000600340 0x0000000000600340
> > 0x1ffcc4 0x1ffcd8 RW  0x200000
> > -  DYNAMIC        0x400360 0x0000000000600360 0x0000000000600360
> > 0x0001e0 0x0001e0 RW  0x8
> > +  LOAD           0x000000 0x0000000000000000 0x0000000000000000
> > 0x0008c8 0x0008c8 R   0x100
> > +  LOAD           0x000900 0x0000000000000900 0x0000000000000900
> > 0x000115 0x000115 R E 0x100
> > +  LOAD           0x000b00 0x0000000000000b00 0x0000000000000b00
> > 0x000098 0x000098 R   0x100
> > +  LOAD           0x000c18 0x0000000000000c18 0x0000000000000c18
> > 0x000200 0x000208 RW  0x100
> > +  DYNAMIC        0x000c30 0x0000000000000c30 0x0000000000000c30
> > 0x0001b0 0x0001b0 RW  0x8
> >    NOTE           0x0002a8 0x00000000000002a8 0x00000000000002a8
> > 0x000050 0x000050 R   0x8
> >    NOTE           0x0002f8 0x00000000000002f8 0x00000000000002f8
> > 0x000044 0x000044 R   0x4
> >    GNU_PROPERTY   0x0002a8 0x00000000000002a8 0x00000000000002a8
> > 0x000050 0x000050 R   0x8
> > -  GNU_EH_FRAME   0x400118 0x0000000000400118 0x0000000000400118
> > 0x000074 0x000074 R   0x4
> > +  GNU_EH_FRAME   0x000b00 0x0000000000000b00 0x0000000000000b00
> > 0x000024 0x000024 R   0x4
> >    GNU_STACK      0x000000 0x0000000000000000 0x0000000000000000
> > 0x000000 0x000000 RW  0x10
> > -  GNU_RELRO      0x400340 0x0000000000600340 0x0000000000600340
> > 0x000cc0 0x000cc0 R   0x1
> > +  GNU_RELRO      0x000c18 0x0000000000000c18 0x0000000000000c18
> > 0x0001e8 0x0001e8 R   0x1
> >
> >   Section to Segment mapping:
> >    Segment Sections...
> > -   00     .note.gnu.property .note.gnu.build-id .note.ABI-tag .hash
> > .gnu.hash .dynsym .dynstr .gnu.version .gnu.version_r .rela.dyn
> > .rela.plt
> > -   01     .init .plt .plt.got .plt.sec .text .fini
> > -   02     .rodata .eh_frame_hdr .eh_frame
> > -   03     .init_array .fini_array .data.rel.ro .dynamic .got .got.plt
> > .data .bss
> > +   00     .note.gnu.property .note.gnu.build-id .note.ABI-tag .hash
> > .gnu.hash .dynsym .dynstr .gnu.version .gnu.version_r .rela.dyn
> > +   01     .init .plt .plt.got .text .fini
> > +   02     .eh_frame_hdr .eh_frame
> > +   03     .init_array .fini_array .data.rel.ro .dynamic .got .got.plt .bss
> >     04     .dynamic
> >     05     .note.gnu.property
> >     06     .note.gnu.build-id .note.ABI-tag
> >



-- 
H.J.