[PATCH v2 0/4] linux-user: Fix siginfo_t contents when jumping to non-readable pages

Ilya Leoshkevich posted 4 patches 6 days, 7 hours ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20220805160914.1106091-1-iii@linux.ibm.com
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, Eduardo Habkost <eduardo@habkost.net>, David Hildenbrand <david@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, "Alex Bennée" <alex.bennee@linaro.org>
accel/tcg/translate-all.c        |  17 ++--
include/exec/translator.h        |  10 +++
target/i386/tcg/translate.c      |  42 ++++++++-
target/s390x/tcg/translate.c     |  35 ++++----
tests/tcg/multiarch/noexec.h     | 114 ++++++++++++++++++++++++
tests/tcg/s390x/Makefile.target  |   1 +
tests/tcg/s390x/noexec.c         | 145 +++++++++++++++++++++++++++++++
tests/tcg/x86_64/Makefile.target |   3 +-
tests/tcg/x86_64/noexec.c        | 116 +++++++++++++++++++++++++
9 files changed, 461 insertions(+), 22 deletions(-)
create mode 100644 tests/tcg/multiarch/noexec.h
create mode 100644 tests/tcg/s390x/noexec.c
create mode 100644 tests/tcg/x86_64/noexec.c
[PATCH v2 0/4] linux-user: Fix siginfo_t contents when jumping to non-readable pages
Posted by Ilya Leoshkevich 6 days, 7 hours ago
Hi,

I noticed that when we get a SEGV due to jumping to non-readable
memory, sometimes si_addr and program counter in siginfo_t are slightly
off. I tracked this down to the assumption that translators stop before
the end of a page, while in reality they may stop right after it.

Patch 1 fixes a minor invalidation issue, which may prevent SEGV from
happening altogether.
Patches 2-3 fix the main issue on x86_64 and s390x. Many other
architectures have fixed-size instructions and are not affected.
Patch 4 adds tests.

Best regards,
Ilya

v1: https://lists.gnu.org/archive/html/qemu-devel/2022-08/msg00822.html
v1 -> v2: Fix individual translators instead of translator_loop
          (Peter).

Ilya Leoshkevich (4):
  accel/tcg: Invalidate translations when clearing PAGE_READ
  target/s390x: Make translator stop before the end of a page
  target/i386: Make translator stop before the end of a page
  tests/tcg: Test siginfo_t contents when jumping to non-readable pages

 accel/tcg/translate-all.c        |  17 ++--
 include/exec/translator.h        |  10 +++
 target/i386/tcg/translate.c      |  42 ++++++++-
 target/s390x/tcg/translate.c     |  35 ++++----
 tests/tcg/multiarch/noexec.h     | 114 ++++++++++++++++++++++++
 tests/tcg/s390x/Makefile.target  |   1 +
 tests/tcg/s390x/noexec.c         | 145 +++++++++++++++++++++++++++++++
 tests/tcg/x86_64/Makefile.target |   3 +-
 tests/tcg/x86_64/noexec.c        | 116 +++++++++++++++++++++++++
 9 files changed, 461 insertions(+), 22 deletions(-)
 create mode 100644 tests/tcg/multiarch/noexec.h
 create mode 100644 tests/tcg/s390x/noexec.c
 create mode 100644 tests/tcg/x86_64/noexec.c

-- 
2.35.3