Date: Thu, 27 Jun 2019 14:00:11 -0700 From: Mark Millard <marklmi@yahoo.com> To: freeBSD PowerPC ML <freebsd-ppc@freebsd.org> Subject: A limitation on the new powerpc (32-bit) use of secure PLT instead of bss PLT? Message-ID: <519C648F-58B9-4328-A8E0-C6F78E4CD2DE@yahoo.com>
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Looking around I ran into from a .../binutils-2_25_1/bfd/elf32-ppc.c :
/* Profiling of shared libs (and pies) is not supported with
secure plt, because ppc32 does profiling before a
function prologue and a secure plt pic call stubs needs
r30 to be set up. */
A little more context for this in ppc_elf_select_plt_layout is:
if (htab->plt_type == PLT_UNSET)
{
struct elf_link_hash_entry *h;
if (htab->params->plt_style == PLT_OLD)
htab->plt_type = PLT_OLD;
else if (info->shared
&& htab->elf.dynamic_sections_created
&& (h = elf_link_hash_lookup (&htab->elf, "_mcount",
FALSE, FALSE, TRUE)) != NULL
&& (h->type == STT_FUNC
|| h->needs_plt)
&& h->ref_regular
&& !(SYMBOL_CALLS_LOCAL (info, h)
|| (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
&& h->root.type == bfd_link_hash_undefweak)))
{
/* Profiling of shared libs (and pies) is not supported with
secure plt, because ppc32 does profiling before a
function prologue and a secure plt pic call stubs needs
r30 to be set up. */
htab->plt_type = PLT_OLD;
}
else
. . .
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
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