[PATCH 09/15] grub_dl_load_segments(): page-align the tramp/GOT areas too

[Mate Kukri]

From: Laszlo Ersek <lersek@redhat.com>

The tramp/GOT write-protection in grub_dl_set_mem_attrs() requires that
the tramp/GOT areas of the module image *not* share a page with any other
memory allocations. Page-align the tramp/GOT areas, while satisfying their
intrinsic alignment requirements too.

Fixes: 887f1d8fa976 (modules: load module sections at page-aligned addresses)
Fixes: ad1b904d325b (nx: set page permissions for loaded modules.)
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
(cherry picked from commit c3569e4a245c21a3806ca122ee88da7c91d3d454)
Signed-off-by: Jan Setje-Eilers <jan.setjeeilers@oracle.com>

 Conflicts:
        grub-core/kern/dl.c (obvious)

Signed-off-by: Mate Kukri <mate.kukri@canonical.com>
---
 grub-core/kern/dl.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/grub-core/kern/dl.c b/grub-core/kern/dl.c
index 2784fae7a..9f31ad3b9 100644
--- a/grub-core/kern/dl.c
+++ b/grub-core/kern/dl.c
@@ -228,7 +228,9 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
 #if !defined (__i386__) && !defined (__x86_64__) && !defined(__riscv) && \
   !defined (__loongarch__)
   grub_size_t tramp;
+  grub_size_t tramp_align;
   grub_size_t got;
+  grub_size_t got_align;
   grub_err_t err;
 #endif
   char *ptr;
@@ -260,12 +262,18 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
   err = grub_arch_dl_get_tramp_got_size (e, &tramp, &got);
   if (err)
     return err;
-  tsize += ALIGN_UP (tramp, GRUB_ARCH_DL_TRAMP_ALIGN);
-  if (talign < GRUB_ARCH_DL_TRAMP_ALIGN)
-    talign = GRUB_ARCH_DL_TRAMP_ALIGN;
-  tsize += ALIGN_UP (got, GRUB_ARCH_DL_GOT_ALIGN);
-  if (talign < GRUB_ARCH_DL_GOT_ALIGN)
-    talign = GRUB_ARCH_DL_GOT_ALIGN;
+  tramp_align = GRUB_ARCH_DL_TRAMP_ALIGN;
+  if (tramp_align < arch_addralign)
+    tramp_align = arch_addralign;
+  tsize += ALIGN_UP (tramp, tramp_align);
+  if (talign < tramp_align)
+    talign = tramp_align;
+  got_align = GRUB_ARCH_DL_GOT_ALIGN;
+  if (got_align < arch_addralign)
+    got_align = arch_addralign;
+  tsize += ALIGN_UP (got, got_align);
+  if (talign < got_align)
+    talign = got_align;
 #endif
 
 #ifdef GRUB_MACHINE_EMU
@@ -326,11 +334,11 @@ grub_dl_load_segments (grub_dl_t mod, const Elf_Ehdr *e)
     }
 #if !defined (__i386__) && !defined (__x86_64__) && !defined(__riscv) && \
   !defined (__loongarch__)
-  ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, GRUB_ARCH_DL_TRAMP_ALIGN);
+  ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, tramp_align);
   mod->tramp = ptr;
   mod->trampptr = ptr;
   ptr += tramp;
-  ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, GRUB_ARCH_DL_GOT_ALIGN);
+  ptr = (char *) ALIGN_UP ((grub_addr_t) ptr, got_align);
   mod->got = ptr;
   mod->gotptr = ptr;
   ptr += got;
-- 
2.39.2