Re: [edk2-devel] : Query regarding IsTextShdr inside Basetools


Mukesh Ojha
 

Apology for rushing into this.
Looking for a quick input on this.

-Mukesh

On 11/10/2020 6:37 PM, Mukesh Ojha wrote:
Hi All,

I have a doubt about the check we have put inside IsTextShdr() .

STATIC
BOOLEAN
IsTextShdr (
  Elf_Shdr *Shdr
  )
{
  return (BOOLEAN) ((Shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == SHF_ALLOC);
}


We are observing one issue where while generate EFI using GenFW in EDK2 because test/data section offset is different than calculated mCoffSectionsOffset when scanning sections.
I run GenFW with a failure dll in my local after adding some logs into GenFW. and found that “mCoffSectionsOffset” for data ection seems not to have expected value due to
“.note.gnu.property” size. Because compiled dll has “.note.gnu.property” section with alloc flag and GenFW thinks that it’s a text section if alloc flag is set.
So its size is added to the mCoffSectionsOffset.

Could you please give us an advice whether we can fix IsTextShdr() function like below ?


--- a/BaseTools/Source/C/GenFw/Elf64Convert.c
+++ b/BaseTools/Source/C/GenFw/Elf64Convert.c
@@ -229,7 +229,7 @@ IsTextShdr (
   Elf_Shdr *Shdr
   )
{
-  return (BOOLEAN) ((Shdr->sh_flags & (SHF_WRITE | SHF_ALLOC)) == SHF_ALLOC);
+  return (BOOLEAN) ((Shdr->sh_flags & (SHF_EXECINSTR | SHF_WRITE | SHF_ALLOC)) == (SHF_ALLOC | SHF_EXECINSTR));^


Thanks,
Mukesh



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