Merge tag 'linux-user-brk-fixes-pull-request' of https://github.com/hdeller/qemu-hppa into staging

linux-user: brk() syscall fixes and armhf static binary fix

Commit 86f04735ac ("linux-user: Fix brk() to release pages") introduced
the possibility for userspace applications to reduce memory footprint by
calling brk() with a lower address and as such free up memory, the same
way as the Linux kernel allows on physical machines.

This change introduced some failures for applications with errors like
- accesing bytes above the brk heap address on the same page,
- freeing memory below the initial brk address,
and introduced a behaviour which isn't done by the kernel (e.g. zeroing
memory above brk).

This patch series fixes those issues and has been tested with existing
programs (e.g. upx).

Additionally one patch fixes running static armhf executables (e.g. fstype)
which was broken since qemu-8.0.

Changes in v2:
- dropped patch to revert d28b3c90cfad ("linux-user: Make sure initial brk(0)
  is page-aligned")
- rephrased some commit messages
- fixed Cc email addresses, added new ones
- added R-b tags

Helge

# -----BEGIN PGP SIGNATURE-----
#
# iHUEABYKAB0WIQS86RI+GtKfB8BJu973ErUQojoPXwUCZLgGswAKCRD3ErUQojoP
# XwkUAQCKb/lkI3IYxiqO48rVyHtLPtkXd+WttFpeZ076p73LTgD+IEpHZL4WV1Rw
# 4+eqW9vswjZwp1xm9bItLdnP2hkyUgI=
# =K3Va
# -----END PGP SIGNATURE-----
# gpg: Signature made Wed 19 Jul 2023 16:52:19 BST
# gpg:                using EDDSA key BCE9123E1AD29F07C049BBDEF712B510A23A0F5F
# gpg: Good signature from "Helge Deller <deller@gmx.de>" [unknown]
# gpg:                 aka "Helge Deller <deller@kernel.org>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 4544 8228 2CD9 10DB EF3D  25F8 3E5F 3D04 A7A2 4603
#      Subkey fingerprint: BCE9 123E 1AD2 9F07 C049  BBDE F712 B510 A23A 0F5F

* tag 'linux-user-brk-fixes-pull-request' of https://github.com/hdeller/qemu-hppa:
  linux-user: Fix qemu-arm to run static armhf binaries
  linux-user: Fix strace output for old_mmap
  linux-user: Fix signed math overflow in brk() syscall
  linux-user: Prohibit brk() to to shrink below initial heap address
  linux-user: Fix qemu brk() to not zero bytes on current page

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 861ec07abc..88c6861d7d 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -3618,6 +3618,13 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
 
     if (elf_interpreter) {
         load_elf_interp(elf_interpreter, &interp_info, bprm->buf);
+        /*
+         * adjust brk address if the interpreter was loaded above the main
+         * executable, e.g. happens with static binaries on armhf
+         */
+        if (interp_info.brk > info->brk) {
+            info->brk = interp_info.brk;
+        }
 
         /* If the program interpreter is one of these two, then assume
            an iBCS2 image.  Otherwise assume a native linux image.  */