From: Kevin Buettner Date: Thu, 5 Mar 2020 00:42:40 +0000 (-0700) Subject: Remove hack for GDB which sets the section size to 0 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ea57e509a23223556c5aede50da8a2aa23a95912;p=binutils-gdb.git Remove hack for GDB which sets the section size to 0 This commit removes a hack for GDB which was introduced in 2007. See: https://sourceware.org/ml/binutils/2007-08/msg00044.html That hack mostly allowed GDB's handling of core files to continue to work without any changes to GDB. The problem with setting the section size to zero is that GDB won't know how big that section is/was. Often, this doesn't matter because the data in question are found in the exec file. But it can happen that the section describes memory that had been allocated, but never written to. In this instance, the contents of that memory region are not written to the core file. Also, since the region in question was dynamically allocated, it won't appear in the exec file. We don't want these regions to appear as inaccessible to GDB (since they *were* accessible when the process was live), so it's important that GDB know the size of the region. I've made changes to GDB which correctly handles this case. When attempting to access memory, GDB will first consider core file data for which both SEC_ALLOC and SEC_HAS_CONTENTS is set. Next, if that fails, GDB will attempt to find the data in the exec file. Finally, if that also fails, GDB will attempt to access memory in the sections which are flagged as SEC_ALLOC, but not SEC_HAS_CONTENTS. bfd/ChangeLog: * elf.c (_bfd_elf_make_section_from_phdr): Remove hack for GDB. --- diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 411c19068df..adbf6f3b20b 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,7 @@ +2020-07-22 Kevin Buettner + + * elf.c (_bfd_elf_make_section_from_phdr): Remove hack for GDB. + 2020-07-22 Max Filippov PR 26246 diff --git a/bfd/elf.c b/bfd/elf.c index 9ca42e10d8e..991a71ca32a 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -3026,14 +3026,6 @@ _bfd_elf_make_section_from_phdr (bfd *abfd, newsect->alignment_power = bfd_log2 (align); if (hdr->p_type == PT_LOAD) { - /* Hack for gdb. Segments that have not been modified do - not have their contents written to a core file, on the - assumption that a debugger can find the contents in the - executable. We flag this case by setting the fake - section size to zero. Note that "real" bss sections will - always have their contents dumped to the core file. */ - if (bfd_get_format (abfd) == bfd_core) - newsect->size = 0; newsect->flags |= SEC_ALLOC; if (hdr->p_flags & PF_X) newsect->flags |= SEC_CODE;