linux-user: Tell guest about big host page sizes

We tell the guest its page size via AUX vectors. The guest process then uses
this page size as information on which boundaries it can mmap() things.

However, if the host has a bigger page size granularity than the guest, it can
not fulfill these mmap() requests - which falls apart when MAP_FIXED is passed
to mmap.

So in that case, let the guest know that we're running on a bigger page size
granularity than the target would require.

This fixes running qemu-ppc (TARGET_PAGE_SIZE=4k) on a 64k page size ppc64 host
for me.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index eb8d3adce3d06520297add3dd60f9143e5a68717..c123244ecd48c20eea66265b7b1979e31ac66be3 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -1552,7 +1552,7 @@ static abi_ulong create_elf_tables(abi_ulong p, int argc, int envc,
     NEW_AUX_ENT(AT_PHDR, (abi_ulong)(info->load_addr + exec->e_phoff));
     NEW_AUX_ENT(AT_PHENT, (abi_ulong)(sizeof (struct elf_phdr)));
     NEW_AUX_ENT(AT_PHNUM, (abi_ulong)(exec->e_phnum));
-    NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(TARGET_PAGE_SIZE));
+    NEW_AUX_ENT(AT_PAGESZ, (abi_ulong)(MAX(TARGET_PAGE_SIZE, getpagesize())));
     NEW_AUX_ENT(AT_BASE, (abi_ulong)(interp_info ? interp_info->load_addr : 0));
     NEW_AUX_ENT(AT_FLAGS, (abi_ulong)0);
     NEW_AUX_ENT(AT_ENTRY, info->entry);