From 2c9e9550caf28bceb6b8540520f7378e1b1bb9c2 Mon Sep 17 00:00:00 2001 From: John David Anglin Date: Sun, 20 Oct 2019 12:01:58 -0400 Subject: [PATCH] [bfd] Provide 8-byte minimum alignment for .plt section This change increases the default alignment for the .plt section from 4 bytes to 8 bytes. When function descriptors are 8-byte aligned, they can be updated atomically on 32-bit hppa. This helps with ordering issues on SMP machines. It also ensures that descriptors reside on the same cache line. This reduces the probability of a double TLB miss in a call. 2019-10-20 John David Anglin * elf32-hppa.c (elf32_hppa_size_dynamic_sections): Provide 8-byte minimum alignment for .plt section. --- bfd/ChangeLog | 5 +++++ bfd/elf32-hppa.c | 5 +++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 44790fb16b7..429e423caa8 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,8 @@ +2019-10-20 John David Anglin + + * elf32-hppa.c (elf32_hppa_size_dynamic_sections): Provide 8-byte + minimum alignment for .plt section. + 2019-10-19 John David Anglin * elf32-hppa.c: Revise import stub sequences. diff --git a/bfd/elf32-hppa.c b/bfd/elf32-hppa.c index 8a19c193708..35564dd2b0b 100644 --- a/bfd/elf32-hppa.c +++ b/bfd/elf32-hppa.c @@ -2280,10 +2280,11 @@ elf32_hppa_size_dynamic_sections (bfd *output_bfd ATTRIBUTE_UNUSED, against the .got section. */ int gotalign = bfd_section_alignment (htab->etab.sgot); int pltalign = bfd_section_alignment (sec); + int align = gotalign > 3 ? gotalign : 3; bfd_size_type mask; - if (gotalign > pltalign) - bfd_set_section_alignment (sec, gotalign); + if (align > pltalign) + bfd_set_section_alignment (sec, align); mask = ((bfd_size_type) 1 << gotalign) - 1; sec->size = (sec->size + sizeof (plt_stub) + mask) & ~mask; } -- 2.30.2