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 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

@@ -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.