From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Mon, 21 Mar 2022 16:56:10 -0400

Subject: [PATCH] modules: Don't allocate space for non-allocable sections.

Currently when loading grub modules, we allocate space for all sections,

including those without SHF_ALLOC set.  We then copy the sections that

/do/ have SHF_ALLOC set into the allocated memory, leaving some of our

allocation untouched forever.  Additionally, on platforms with GOT

fixups and trampolines, we currently compute alignment round-ups for the

sections and sections with sh_size = 0.

This patch removes the extra space from the allocation computation, and

makes the allocation computation loop skip empty sections as the loading

loop does.

Signed-off-by: Peter Jones <pjones@redhat.com>

---

 grub-core/kern/dl.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c

index f304494574..aef8af8aa7 100644

--- a/grub-core/kern/dl.c

+++ b/grub-core/kern/dl.c

@@ -289,6 +289,9 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)

        i < e->e_shnum;

        i++, s = (const Elf_Shdr *)((const char *) s + e->e_shentsize))

     {

+      if (s->sh_size == 0 || !(s->sh_flags & SHF_ALLOC))

+	continue;

+

       tsize = ALIGN_UP (tsize, s->sh_addralign) + s->sh_size;

       if (talign < s->sh_addralign)

 	talign = s->sh_addralign;