Re: [PATCH v6 00/21] linux-user: Fix siginfo_t contents when jumping to non-readable pages

[Vivian Wang]

On 8/19/22 11:25, Richard Henderson wrote:
> Hi Ilya,
>
> After adding support for riscv (similar to s390x, in that we can
> find the total insn length from the first couple of bits, so, easy),
> I find that the test case doesn't work without all of the other
> changes for PROT_EXEC, including the translator_ld changes.
>
> Other changes from your v5:
>   - mprotect invalidates tbs.  The test case is riscv, with a
>     4-byte insn at offset 0xffe, which was chained to from the
>     insn at offset 0xffa.  The fact that the 0xffe tb was not
>     invalidated meant that we chained to it and re-executed
>     without revalidating page protections.
>
>   - rewrote the test framework to be agnostic of page size, which
>     reduces some of the repetition.  I ran into trouble with the
>     riscv linker, which relaxed the segment such that .align+.org
>     wasn't actually honored.  This new form doesn't require the
>     test bytes to be aligned in the binary.
>
>
> r~
I've confirmed that this fixes #1155

Tested-by: Vivian Wang <dramforever@live.com>

> Ilya Leoshkevich (4):
>   linux-user: Clear translations and tb_jmp_cache on mprotect()
>   accel/tcg: Introduce is_same_page()
>   target/s390x: Make translator stop before the end of a page
>   target/i386: Make translator stop before the end of a page
>
> Richard Henderson (17):
>   linux-user/arm: Mark the commpage executable
>   linux-user/hppa: Allocate page zero as a commpage
>   linux-user/x86_64: Allocate vsyscall page as a commpage
>   linux-user: Honor PT_GNU_STACK
>   tests/tcg/i386: Move smc_code2 to an executable section
>   accel/tcg: Properly implement get_page_addr_code for user-only
>   accel/tcg: Unlock mmap_lock after longjmp
>   accel/tcg: Make tb_htable_lookup static
>   accel/tcg: Move qemu_ram_addr_from_host_nofail to physmem.c
>   accel/tcg: Use probe_access_internal for softmmu
>     get_page_addr_code_hostp
>   accel/tcg: Add nofault parameter to get_page_addr_code_hostp
>   accel/tcg: Raise PROT_EXEC exception early
>   accel/tcg: Remove translator_ldsw
>   accel/tcg: Add pc and host_pc params to gen_intermediate_code
>   accel/tcg: Add fast path for translator_ld*
>   target/riscv: Add MAX_INSN_LEN and insn_len
>   target/riscv: Make translator stop before the end of a page
>
>  include/elf.h                     |   1 +
>  include/exec/cpu-common.h         |   1 +
>  include/exec/exec-all.h           |  87 ++++++------------
>  include/exec/translator.h         |  96 +++++++++++++-------
>  linux-user/arm/target_cpu.h       |   4 +-
>  linux-user/qemu.h                 |   1 +
>  accel/tcg/cpu-exec.c              | 134 ++++++++++++++--------------
>  accel/tcg/cputlb.c                |  93 ++++++--------------
>  accel/tcg/plugin-gen.c            |   4 +-
>  accel/tcg/translate-all.c         |  29 +++---
>  accel/tcg/translator.c            | 136 +++++++++++++++++++++-------
>  accel/tcg/user-exec.c             |  18 +++-
>  linux-user/elfload.c              |  82 +++++++++++++++--
>  linux-user/mmap.c                 |   8 ++
>  softmmu/physmem.c                 |  12 +++
>  target/alpha/translate.c          |   5 +-
>  target/arm/translate.c            |   5 +-
>  target/avr/translate.c            |   5 +-
>  target/cris/translate.c           |   5 +-
>  target/hexagon/translate.c        |   6 +-
>  target/hppa/translate.c           |   5 +-
>  target/i386/tcg/translate.c       |  32 ++++++-
>  target/loongarch/translate.c      |   6 +-
>  target/m68k/translate.c           |   5 +-
>  target/microblaze/translate.c     |   5 +-
>  target/mips/tcg/translate.c       |   5 +-
>  target/nios2/translate.c          |   5 +-
>  target/openrisc/translate.c       |   6 +-
>  target/ppc/translate.c            |   5 +-
>  target/riscv/translate.c          |  32 +++++--
>  target/rx/translate.c             |   5 +-
>  target/s390x/tcg/translate.c      |  20 +++--
>  target/sh4/translate.c            |   5 +-
>  target/sparc/translate.c          |   5 +-
>  target/tricore/translate.c        |   6 +-
>  target/xtensa/translate.c         |   6 +-
>  tests/tcg/i386/test-i386.c        |   2 +-
>  tests/tcg/riscv64/noexec.c        |  79 +++++++++++++++++
>  tests/tcg/s390x/noexec.c          | 106 ++++++++++++++++++++++
>  tests/tcg/x86_64/noexec.c         |  75 ++++++++++++++++
>  tests/tcg/multiarch/noexec.c.inc  | 141 ++++++++++++++++++++++++++++++
>  tests/tcg/riscv64/Makefile.target |   1 +
>  tests/tcg/s390x/Makefile.target   |   1 +
>  tests/tcg/x86_64/Makefile.target  |   3 +-
>  44 files changed, 951 insertions(+), 342 deletions(-)
>  create mode 100644 tests/tcg/riscv64/noexec.c
>  create mode 100644 tests/tcg/s390x/noexec.c
>  create mode 100644 tests/tcg/x86_64/noexec.c
>  create mode 100644 tests/tcg/multiarch/noexec.c.inc
>