Supercedes: <20210619034329.532318-1-richard.henderson@linaro.org>
("[PATCH 00/12] linux-user: Load a vdso for x86_64 and hppa")

Supercedes: <20210618192951.125651-1-richard.henderson@linaro.org>
("[PATCH v2 00/23] linux-user: Move signal trampolines to new page")

Changes for v2:
  * Add vdsos for aarch64, arm, i386, riscv.
  * Drop setup_sigtramp for any target with a vdso.
  * Drop arm v1 signal support.
  * Simplify ppc encode_trampoline.

The remaining linux kernel targets that support vdsos are:

MIPS is particularly troublesome because of a multitude of ISAs.
The kernel doesn't even support them all, disabling the vdso for
micromips (and probably ignores nanomips entirely).  Though I'll
note that linux-user/mips does not handle any of the modern
ISAs -- install_sigtramp is strictly MIPS I.  In addition there
are 3 ELF ABIs, so there's some combinatorial explosion in the
set of vdsos that would need to be pre-built.  Perhaps put this
off until we can build these on demand.

PPC is troublesome because of __kernel_get_syscall_map.
In addition to needing to collect the set of syscalls that qemu
supports, we'd need to update the vdso every time we add support
for a new syscall.  And then there are the 3 ELF ABIs.  So again
put this off until we can build these on demand.

S390x shouldn't be troublesome, I just didn't finish them all.


r~


Richard Henderson (36):
  linux-user: Add infrastructure for a signal trampoline page
  linux-user: Fix style problems in linuxload.c
  linux-user: Introduce imgsrc_read, imgsrc_read_alloc
  linux-user: Tidy loader_exec
  linux-user: Do not clobber bprm_buf swapping ehdr
  linux-user: Use ImageSource in load_elf_image
  linux-user: Use ImageSource in load_symbols
  linux-user: Replace bprm->fd with bprm->src.fd
  linux-user: Introduce imgsrc_mmap
  linux-user: Load vdso image if available
  linux-user: Add gen-vdso tool
  linux-user/aarch64: Add vdso and use it for rt_sigreturn
  linux-user/arm: Drop v1 signal frames
  linux-user/arm: Drop "_v2" from symbols in signal.c
  target/arm: Add isar_feature_aa32_a32
  linux-user/arm: Add vdso and use it for rt_sigreturn
  linux-user/alpha: Implement setup_sigtramp
  linux-user/cris: Implement setup_sigtramp
  linux-user/hexagon: Implement setup_sigtramp
  linux-user/hppa: Add vdso and use it for rt_sigreturn
  linux-user/x86_64: Raise SIGSEGV if SA_RESTORER not set
  linux-user/i386: Add vdso and use it for sigreturn
  linux-user/x86_64: Add vdso
  linux-user/m68k: Implement setup_sigtramp
  linux-user/microblaze: Implement setup_sigtramp
  linux-user/mips: Tidy install_sigtramp
  linux-user/mips: Implement setup_sigtramp
  linux-user/nios2: Document non-use of setup_sigtramp
  linux-user/openrisc: Implement setup_sigtramp
  target/ppc: Simplify encode_trampoline
  linux-user/ppc: Implement setup_sigtramp
  linux-user/riscv: Add vdso and use it for sigreturn
  linux-user/s390x: Implement setup_sigtramp
  linux-user/sh4: Implement setup_sigtramp
  linux-user/sparc: Implement setup_sigtramp
  linux-user/xtensa: Implement setup_sigtramp

 linux-user/alpha/target_signal.h      |   1 +
 linux-user/cris/target_signal.h       |   2 +
 linux-user/hexagon/target_signal.h    |   2 +
 linux-user/m68k/target_signal.h       |   2 +
 linux-user/microblaze/target_signal.h |   2 +
 linux-user/mips/target_signal.h       |   1 +
 linux-user/mips64/target_signal.h     |   2 +
 linux-user/nios2/target_signal.h      |   3 +
 linux-user/openrisc/target_signal.h   |   2 +
 linux-user/ppc/target_signal.h        |   2 +
 linux-user/qemu.h                     |  67 +++-
 linux-user/s390x/target_signal.h      |   2 +
 linux-user/sh4/target_signal.h        |   2 +
 linux-user/sparc/target_signal.h      |   4 +
 linux-user/xtensa/target_signal.h     |   2 +
 target/arm/cpu.h                      |   5 +
 linux-user/aarch64/signal.c           |  17 +-
 linux-user/alpha/signal.c             |  34 +-
 linux-user/arm/signal.c               | 500 ++++++--------------------
 linux-user/cris/signal.c              |  29 +-
 linux-user/elfload.c                  | 367 ++++++++++++-------
 linux-user/flatload.c                 |   8 +-
 linux-user/gen-vdso.c                 | 223 ++++++++++++
 linux-user/hexagon/signal.c           |  19 +-
 linux-user/hppa/signal.c              |   8 +-
 linux-user/i386/signal.c              |  50 +--
 linux-user/linuxload.c                | 171 ++++++---
 linux-user/m68k/signal.c              |  47 ++-
 linux-user/microblaze/signal.c        |  24 +-
 linux-user/mips/signal.c              |  39 +-
 linux-user/openrisc/signal.c          |  24 +-
 linux-user/ppc/signal.c               |  40 +--
 linux-user/riscv/signal.c             |  10 +-
 linux-user/s390x/signal.c             |  24 +-
 linux-user/sh4/signal.c               |  40 ++-
 linux-user/signal.c                   |   3 +
 linux-user/sparc/signal.c             |  32 +-
 linux-user/xtensa/signal.c            |  50 +--
 target/arm/cpu_tcg.c                  |   7 +
 linux-user/gen-vdso-elfn.c.inc        | 306 ++++++++++++++++
 linux-user/aarch64/Makefile.vdso      |  11 +
 linux-user/aarch64/meson.build        |  11 +
 linux-user/aarch64/vdso-be.so         | Bin 0 -> 6000 bytes
 linux-user/aarch64/vdso-le.so         | Bin 0 -> 6000 bytes
 linux-user/aarch64/vdso.S             |  77 ++++
 linux-user/aarch64/vdso.ld            |  74 ++++
 linux-user/arm/Makefile.vdso          |  17 +
 linux-user/arm/meson.build            |  18 +
 linux-user/arm/vdso-arm-be.so         | Bin 0 -> 5648 bytes
 linux-user/arm/vdso-arm-le.so         | Bin 0 -> 5648 bytes
 linux-user/arm/vdso-thm-be.so         | Bin 0 -> 5620 bytes
 linux-user/arm/vdso-thm-le.so         | Bin 0 -> 5620 bytes
 linux-user/arm/vdso.S                 | 209 +++++++++++
 linux-user/arm/vdso.ld                |  74 ++++
 linux-user/hppa/Makefile.vdso         |   6 +
 linux-user/hppa/meson.build           |   6 +
 linux-user/hppa/vdso.S                | 149 ++++++++
 linux-user/hppa/vdso.ld               |  75 ++++
 linux-user/hppa/vdso.so               | Bin 0 -> 5196 bytes
 linux-user/i386/Makefile.vdso         |   5 +
 linux-user/i386/meson.build           |   7 +
 linux-user/i386/vdso.S                | 149 ++++++++
 linux-user/i386/vdso.ld               |  76 ++++
 linux-user/i386/vdso.so               | Bin 0 -> 5528 bytes
 linux-user/meson.build                |   8 +-
 linux-user/riscv/Makefile.vdso        |  11 +
 linux-user/riscv/meson.build          |   9 +
 linux-user/riscv/vdso-32.so           | Bin 0 -> 5624 bytes
 linux-user/riscv/vdso-64.so           | Bin 0 -> 6120 bytes
 linux-user/riscv/vdso.S               | 207 +++++++++++
 linux-user/riscv/vdso.ld              |  76 ++++
 linux-user/x86_64/Makefile.vdso       |   5 +
 linux-user/x86_64/meson.build         |   6 +
 linux-user/x86_64/vdso.S              | 122 +++++++
 linux-user/x86_64/vdso.ld             |  74 ++++
 linux-user/x86_64/vdso.so             | Bin 0 -> 6008 bytes
 76 files changed, 2866 insertions(+), 789 deletions(-)
 create mode 100644 linux-user/gen-vdso.c
 create mode 100644 linux-user/gen-vdso-elfn.c.inc
 create mode 100644 linux-user/aarch64/Makefile.vdso
 create mode 100644 linux-user/aarch64/meson.build
 create mode 100755 linux-user/aarch64/vdso-be.so
 create mode 100755 linux-user/aarch64/vdso-le.so
 create mode 100644 linux-user/aarch64/vdso.S
 create mode 100644 linux-user/aarch64/vdso.ld
 create mode 100644 linux-user/arm/Makefile.vdso
 create mode 100755 linux-user/arm/vdso-arm-be.so
 create mode 100755 linux-user/arm/vdso-arm-le.so
 create mode 100755 linux-user/arm/vdso-thm-be.so
 create mode 100755 linux-user/arm/vdso-thm-le.so
 create mode 100644 linux-user/arm/vdso.S
 create mode 100644 linux-user/arm/vdso.ld
 create mode 100644 linux-user/hppa/Makefile.vdso
 create mode 100644 linux-user/hppa/vdso.S
 create mode 100644 linux-user/hppa/vdso.ld
 create mode 100755 linux-user/hppa/vdso.so
 create mode 100644 linux-user/i386/Makefile.vdso
 create mode 100644 linux-user/i386/vdso.S
 create mode 100644 linux-user/i386/vdso.ld
 create mode 100755 linux-user/i386/vdso.so
 create mode 100644 linux-user/riscv/Makefile.vdso
 create mode 100644 linux-user/riscv/meson.build
 create mode 100755 linux-user/riscv/vdso-32.so
 create mode 100755 linux-user/riscv/vdso-64.so
 create mode 100644 linux-user/riscv/vdso.S
 create mode 100644 linux-user/riscv/vdso.ld
 create mode 100644 linux-user/x86_64/Makefile.vdso
 create mode 100644 linux-user/x86_64/vdso.S
 create mode 100644 linux-user/x86_64/vdso.ld
 create mode 100755 linux-user/x86_64/vdso.so

-- 
2.25.1

On 7/7/21 1:48 AM, Richard Henderson wrote:
> Supercedes: <20210619034329.532318-1-richard.henderson@linaro.org>
> ("[PATCH 00/12] linux-user: Load a vdso for x86_64 and hppa")
> 
> Supercedes: <20210618192951.125651-1-richard.henderson@linaro.org>
> ("[PATCH v2 00/23] linux-user: Move signal trampolines to new page")
> 
> Changes for v2:
>   * Add vdsos for aarch64, arm, i386, riscv.
>   * Drop setup_sigtramp for any target with a vdso.
>   * Drop arm v1 signal support.
>   * Simplify ppc encode_trampoline.
> 
> The remaining linux kernel targets that support vdsos are:
> 
> MIPS is particularly troublesome because of a multitude of ISAs.
> The kernel doesn't even support them all, disabling the vdso for
> micromips (and probably ignores nanomips entirely).  Though I'll
> note that linux-user/mips does not handle any of the modern
> ISAs -- install_sigtramp is strictly MIPS I.  In addition there
> are 3 ELF ABIs, so there's some combinatorial explosion in the
> set of vdsos that would need to be pre-built.  Perhaps put this
> off until we can build these on demand.

Cc'ing Maciej to keep him aware, but FWIW, this sounds good to me.

> PPC is troublesome because of __kernel_get_syscall_map.
> In addition to needing to collect the set of syscalls that qemu
> supports, we'd need to update the vdso every time we add support
> for a new syscall.  And then there are the 3 ELF ABIs.  So again
> put this off until we can build these on demand.
> 
> S390x shouldn't be troublesome, I just didn't finish them all.
> 
> 
> r~
> 
> 
> Richard Henderson (36):
>   linux-user: Add infrastructure for a signal trampoline page
>   linux-user: Fix style problems in linuxload.c
>   linux-user: Introduce imgsrc_read, imgsrc_read_alloc
>   linux-user: Tidy loader_exec
>   linux-user: Do not clobber bprm_buf swapping ehdr
>   linux-user: Use ImageSource in load_elf_image
>   linux-user: Use ImageSource in load_symbols
>   linux-user: Replace bprm->fd with bprm->src.fd
>   linux-user: Introduce imgsrc_mmap
>   linux-user: Load vdso image if available
>   linux-user: Add gen-vdso tool
>   linux-user/aarch64: Add vdso and use it for rt_sigreturn
>   linux-user/arm: Drop v1 signal frames
>   linux-user/arm: Drop "_v2" from symbols in signal.c
>   target/arm: Add isar_feature_aa32_a32
>   linux-user/arm: Add vdso and use it for rt_sigreturn
>   linux-user/alpha: Implement setup_sigtramp
>   linux-user/cris: Implement setup_sigtramp
>   linux-user/hexagon: Implement setup_sigtramp
>   linux-user/hppa: Add vdso and use it for rt_sigreturn
>   linux-user/x86_64: Raise SIGSEGV if SA_RESTORER not set
>   linux-user/i386: Add vdso and use it for sigreturn
>   linux-user/x86_64: Add vdso
>   linux-user/m68k: Implement setup_sigtramp
>   linux-user/microblaze: Implement setup_sigtramp
>   linux-user/mips: Tidy install_sigtramp
>   linux-user/mips: Implement setup_sigtramp
>   linux-user/nios2: Document non-use of setup_sigtramp
>   linux-user/openrisc: Implement setup_sigtramp
>   target/ppc: Simplify encode_trampoline
>   linux-user/ppc: Implement setup_sigtramp
>   linux-user/riscv: Add vdso and use it for sigreturn
>   linux-user/s390x: Implement setup_sigtramp
>   linux-user/sh4: Implement setup_sigtramp
>   linux-user/sparc: Implement setup_sigtramp
>   linux-user/xtensa: Implement setup_sigtramp
> 
>  linux-user/alpha/target_signal.h      |   1 +
>  linux-user/cris/target_signal.h       |   2 +
>  linux-user/hexagon/target_signal.h    |   2 +
>  linux-user/m68k/target_signal.h       |   2 +
>  linux-user/microblaze/target_signal.h |   2 +
>  linux-user/mips/target_signal.h       |   1 +
>  linux-user/mips64/target_signal.h     |   2 +
>  linux-user/nios2/target_signal.h      |   3 +
>  linux-user/openrisc/target_signal.h   |   2 +
>  linux-user/ppc/target_signal.h        |   2 +
>  linux-user/qemu.h                     |  67 +++-
>  linux-user/s390x/target_signal.h      |   2 +
>  linux-user/sh4/target_signal.h        |   2 +
>  linux-user/sparc/target_signal.h      |   4 +
>  linux-user/xtensa/target_signal.h     |   2 +
>  target/arm/cpu.h                      |   5 +
>  linux-user/aarch64/signal.c           |  17 +-
>  linux-user/alpha/signal.c             |  34 +-
>  linux-user/arm/signal.c               | 500 ++++++--------------------
>  linux-user/cris/signal.c              |  29 +-
>  linux-user/elfload.c                  | 367 ++++++++++++-------
>  linux-user/flatload.c                 |   8 +-
>  linux-user/gen-vdso.c                 | 223 ++++++++++++
>  linux-user/hexagon/signal.c           |  19 +-
>  linux-user/hppa/signal.c              |   8 +-
>  linux-user/i386/signal.c              |  50 +--
>  linux-user/linuxload.c                | 171 ++++++---
>  linux-user/m68k/signal.c              |  47 ++-
>  linux-user/microblaze/signal.c        |  24 +-
>  linux-user/mips/signal.c              |  39 +-
>  linux-user/openrisc/signal.c          |  24 +-
>  linux-user/ppc/signal.c               |  40 +--
>  linux-user/riscv/signal.c             |  10 +-
>  linux-user/s390x/signal.c             |  24 +-
>  linux-user/sh4/signal.c               |  40 ++-
>  linux-user/signal.c                   |   3 +
>  linux-user/sparc/signal.c             |  32 +-
>  linux-user/xtensa/signal.c            |  50 +--
>  target/arm/cpu_tcg.c                  |   7 +
>  linux-user/gen-vdso-elfn.c.inc        | 306 ++++++++++++++++
>  linux-user/aarch64/Makefile.vdso      |  11 +
>  linux-user/aarch64/meson.build        |  11 +
>  linux-user/aarch64/vdso-be.so         | Bin 0 -> 6000 bytes
>  linux-user/aarch64/vdso-le.so         | Bin 0 -> 6000 bytes
>  linux-user/aarch64/vdso.S             |  77 ++++
>  linux-user/aarch64/vdso.ld            |  74 ++++
>  linux-user/arm/Makefile.vdso          |  17 +
>  linux-user/arm/meson.build            |  18 +
>  linux-user/arm/vdso-arm-be.so         | Bin 0 -> 5648 bytes
>  linux-user/arm/vdso-arm-le.so         | Bin 0 -> 5648 bytes
>  linux-user/arm/vdso-thm-be.so         | Bin 0 -> 5620 bytes
>  linux-user/arm/vdso-thm-le.so         | Bin 0 -> 5620 bytes
>  linux-user/arm/vdso.S                 | 209 +++++++++++
>  linux-user/arm/vdso.ld                |  74 ++++
>  linux-user/hppa/Makefile.vdso         |   6 +
>  linux-user/hppa/meson.build           |   6 +
>  linux-user/hppa/vdso.S                | 149 ++++++++
>  linux-user/hppa/vdso.ld               |  75 ++++
>  linux-user/hppa/vdso.so               | Bin 0 -> 5196 bytes
>  linux-user/i386/Makefile.vdso         |   5 +
>  linux-user/i386/meson.build           |   7 +
>  linux-user/i386/vdso.S                | 149 ++++++++
>  linux-user/i386/vdso.ld               |  76 ++++
>  linux-user/i386/vdso.so               | Bin 0 -> 5528 bytes
>  linux-user/meson.build                |   8 +-
>  linux-user/riscv/Makefile.vdso        |  11 +
>  linux-user/riscv/meson.build          |   9 +
>  linux-user/riscv/vdso-32.so           | Bin 0 -> 5624 bytes
>  linux-user/riscv/vdso-64.so           | Bin 0 -> 6120 bytes
>  linux-user/riscv/vdso.S               | 207 +++++++++++
>  linux-user/riscv/vdso.ld              |  76 ++++
>  linux-user/x86_64/Makefile.vdso       |   5 +
>  linux-user/x86_64/meson.build         |   6 +
>  linux-user/x86_64/vdso.S              | 122 +++++++
>  linux-user/x86_64/vdso.ld             |  74 ++++
>  linux-user/x86_64/vdso.so             | Bin 0 -> 6008 bytes
>  76 files changed, 2866 insertions(+), 789 deletions(-)
>  create mode 100644 linux-user/gen-vdso.c
>  create mode 100644 linux-user/gen-vdso-elfn.c.inc
>  create mode 100644 linux-user/aarch64/Makefile.vdso
>  create mode 100644 linux-user/aarch64/meson.build
>  create mode 100755 linux-user/aarch64/vdso-be.so
>  create mode 100755 linux-user/aarch64/vdso-le.so
>  create mode 100644 linux-user/aarch64/vdso.S
>  create mode 100644 linux-user/aarch64/vdso.ld
>  create mode 100644 linux-user/arm/Makefile.vdso
>  create mode 100755 linux-user/arm/vdso-arm-be.so
>  create mode 100755 linux-user/arm/vdso-arm-le.so
>  create mode 100755 linux-user/arm/vdso-thm-be.so
>  create mode 100755 linux-user/arm/vdso-thm-le.so
>  create mode 100644 linux-user/arm/vdso.S
>  create mode 100644 linux-user/arm/vdso.ld
>  create mode 100644 linux-user/hppa/Makefile.vdso
>  create mode 100644 linux-user/hppa/vdso.S
>  create mode 100644 linux-user/hppa/vdso.ld
>  create mode 100755 linux-user/hppa/vdso.so
>  create mode 100644 linux-user/i386/Makefile.vdso
>  create mode 100644 linux-user/i386/vdso.S
>  create mode 100644 linux-user/i386/vdso.ld
>  create mode 100755 linux-user/i386/vdso.so
>  create mode 100644 linux-user/riscv/Makefile.vdso
>  create mode 100644 linux-user/riscv/meson.build
>  create mode 100755 linux-user/riscv/vdso-32.so
>  create mode 100755 linux-user/riscv/vdso-64.so
>  create mode 100644 linux-user/riscv/vdso.S
>  create mode 100644 linux-user/riscv/vdso.ld
>  create mode 100644 linux-user/x86_64/Makefile.vdso
>  create mode 100644 linux-user/x86_64/vdso.S
>  create mode 100644 linux-user/x86_64/vdso.ld
>  create mode 100755 linux-user/x86_64/vdso.so
> 

On Wed, 7 Jul 2021 at 00:51, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Supercedes: <20210619034329.532318-1-richard.henderson@linaro.org>
> ("[PATCH 00/12] linux-user: Load a vdso for x86_64 and hppa")
>
> Supercedes: <20210618192951.125651-1-richard.henderson@linaro.org>
> ("[PATCH v2 00/23] linux-user: Move signal trampolines to new page")
>
> Changes for v2:
>   * Add vdsos for aarch64, arm, i386, riscv.
>   * Drop setup_sigtramp for any target with a vdso.
>   * Drop arm v1 signal support.
>   * Simplify ppc encode_trampoline.

I'm not planning to review this series, but a general comment:
I'm not really enthusiastic about the "vdso binaries checked into
git and the build mechanism is a random makefile that has to be
run by hand in the right environment" setup (and distros that
like to build everything from source probably won't be keen
either). At a minimum the handling of the cross-environment
stuff should be more automated and reproducible like 'make check-tcg'.
It would be useful also to get input from the Debian folks on
how they'd want to see the build-from-source requirements/setup
working...

-- PMM

Peter Maydell <peter.maydell@linaro.org> writes:

> On Wed, 7 Jul 2021 at 00:51, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> Supercedes: <20210619034329.532318-1-richard.henderson@linaro.org>
>> ("[PATCH 00/12] linux-user: Load a vdso for x86_64 and hppa")
>>
>> Supercedes: <20210618192951.125651-1-richard.henderson@linaro.org>
>> ("[PATCH v2 00/23] linux-user: Move signal trampolines to new page")
>>
>> Changes for v2:
>>   * Add vdsos for aarch64, arm, i386, riscv.
>>   * Drop setup_sigtramp for any target with a vdso.
>>   * Drop arm v1 signal support.
>>   * Simplify ppc encode_trampoline.
>
> I'm not planning to review this series, but a general comment:
> I'm not really enthusiastic about the "vdso binaries checked into
> git and the build mechanism is a random makefile that has to be
> run by hand in the right environment" setup (and distros that
> like to build everything from source probably won't be keen
> either).

AIUI the vdso's are really pretty simple stubs more in line with our
stub launchers we currently have scattered around in our sources as hex
bytes. They are a bit bigger but not by much.

> At a minimum the handling of the cross-environment
> stuff should be more automated and reproducible like 'make check-tcg'.
> It would be useful also to get input from the Debian folks on
> how they'd want to see the build-from-source requirements/setup
> working...

In Debian they require cross compilers so they can build the various
blobs we use. However those blobs are packaged as "noarch" blobs and
only built on x86 where all the cross compilers are functional. This is
the reason you can't do a full build of QEMU packages on non-x86
platforms and why you need:

  apt build-dep -yy -a arm64 --arch-only qemu

so it doesn't barf trying to find cross compilers that haven't been
built for the host arch. So far my attempts to suggest the distros just
simply package all cross compilers on all supported host architectures
have been rebuffed on the basis it does tend to explode the build matrix
a bit.

The check-tcg compiler logic could be used to build the vdso's but it is
currently optional so if we can't run them you don't get any tests. I
suspect we still need to package the binary vdso blobs but use the
check-tcg machinery to rebuild them when we can.

>
> -- PMM


-- 
Alex Bennée

On 9/3/21 3:39 PM, Alex Bennée wrote:
> The check-tcg compiler logic could be used to build the vdso's but it is
> currently optional so if we can't run them you don't get any tests. I
> suspect we still need to package the binary vdso blobs but use the
> check-tcg machinery to rebuild them when we can.

This is what I was hoping for.

I was going to suggest that we migrate the check-tcg machinery into meson, so that the 
tests could be migrated out of their special makefiles and that we could re-use that for 
the vdsos.


r~