Re: [RFC PATCH 4/4] hurd: Implement prefer_map_32bit_exec tunable

[Samuel Thibault]

Applied, thanks!

Sergey Bugaev, le lun. 24 avril 2023 00:55:26 +0300, a ecrit:
> This makes the prefer_map_32bit_exec tunable no longer Linux-specific.
> 
> Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
> ---
>  sysdeps/mach/hurd/dl-sysdep.c                 |  5 ++++
>  sysdeps/mach/hurd/mmap.c                      |  6 +++++
>  sysdeps/unix/sysv/linux/x86_64/64/Makefile    | 23 -------------------
>  sysdeps/x86_64/64/Makefile                    | 22 ++++++++++++++++++
>  .../linux => }/x86_64/64/dl-tunables.list     |  0
>  .../linux => }/x86_64/64/tst-map-32bit-1a.c   |  0
>  .../linux => }/x86_64/64/tst-map-32bit-1b.c   |  0
>  .../linux => }/x86_64/64/tst-map-32bit-mod.c  |  0
>  8 files changed, 33 insertions(+), 23 deletions(-)
>  create mode 100644 sysdeps/x86_64/64/Makefile
>  rename sysdeps/{unix/sysv/linux => }/x86_64/64/dl-tunables.list (100%)
>  rename sysdeps/{unix/sysv/linux => }/x86_64/64/tst-map-32bit-1a.c (100%)
>  rename sysdeps/{unix/sysv/linux => }/x86_64/64/tst-map-32bit-1b.c (100%)
>  rename sysdeps/{unix/sysv/linux => }/x86_64/64/tst-map-32bit-mod.c (100%)
> 
> diff --git a/sysdeps/mach/hurd/dl-sysdep.c b/sysdeps/mach/hurd/dl-sysdep.c
> index 25a12774..79ebb0ce 100644
> --- a/sysdeps/mach/hurd/dl-sysdep.c
> +++ b/sysdeps/mach/hurd/dl-sysdep.c
> @@ -462,6 +462,11 @@ __mmap (void *addr, size_t len, int prot, int flags, int 
> fd, off_t offset)
>    if (prot & PROT_EXEC)
>      vmprot |= VM_PROT_EXECUTE;
>  
> +#ifdef __LP64__
> +  if ((addr == NULL) && (prot & PROT_EXEC)
> +      && HAS_ARCH_FEATURE (Prefer_MAP_32BIT_EXEC))
> +    flags |= MAP_32BIT;
> +#endif
>    mask = (flags & MAP_32BIT) ? ~(vm_address_t) 0x7FFFFFFF : 0;
>  
>    if (flags & MAP_ANON)
> diff --git a/sysdeps/mach/hurd/mmap.c b/sysdeps/mach/hurd/mmap.c
> index d570be24..c4ffbba3 100644
> --- a/sysdeps/mach/hurd/mmap.c
> +++ b/sysdeps/mach/hurd/mmap.c
> @@ -18,6 +18,7 @@
>  #include <sys/types.h>
>  #include <sys/mman.h>
>  #include <errno.h>
> +#include <ldsodefs.h>
>  #include <hurd.h>
>  #include <hurd/fd.h>
>  
> @@ -56,6 +57,11 @@ __mmap (void *addr, size_t len, int prot, int flags, int 
> fd, off_t offset)
>  
>    copy = ! (flags & MAP_SHARED);
>  
> +#ifdef __LP64__
> +  if ((addr == NULL) && (prot & PROT_EXEC)
> +      && HAS_ARCH_FEATURE (Prefer_MAP_32BIT_EXEC))
> +    flags |= MAP_32BIT;
> +#endif
>    mask = (flags & MAP_32BIT) ? ~(vm_address_t) 0x7FFFFFFF : 0;
>  
>    switch (flags & MAP_TYPE)
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/Makefile 
> b/sysdeps/unix/sysv/linux/x86_64/64/Makefile
> index 1bf7d528..a7b6dc5a 100644
> --- a/sysdeps/unix/sysv/linux/x86_64/64/Makefile
> +++ b/sysdeps/unix/sysv/linux/x86_64/64/Makefile
> @@ -1,25 +1,2 @@
>  # The default ABI is 64.
>  default-abi := 64
> -
> -ifeq ($(subdir),elf)
> -
> -tests-map-32bit = \
> -  tst-map-32bit-1a \
> -  tst-map-32bit-1b \
> -# tests-map-32bit
> -tst-map-32bit-1a-no-pie = yes
> -tst-map-32bit-1b-no-pie = yes
> -tests += $(tests-map-32bit)
> -
> -modules-map-32bit = \
> -  tst-map-32bit-mod \
> -# modules-map-32bit
> -modules-names += $(modules-map-32bit)
> -
> -$(objpfx)tst-map-32bit-mod.so: $(libsupport)
> -tst-map-32bit-1a-ENV = LD_PREFER_MAP_32BIT_EXEC=1
> -$(objpfx)tst-map-32bit-1a: $(objpfx)tst-map-32bit-mod.so
> -tst-map-32bit-1b-ENV = GLIBC_TUNABLES=glibc.cpu.prefer_map_32bit_exec=1
> -$(objpfx)tst-map-32bit-1b: $(objpfx)tst-map-32bit-mod.so
> -
> -endif
> diff --git a/sysdeps/x86_64/64/Makefile b/sysdeps/x86_64/64/Makefile
> new file mode 100644
> index 00000000..73fcfe0b
> --- /dev/null
> +++ b/sysdeps/x86_64/64/Makefile
> @@ -0,0 +1,22 @@
> +ifeq ($(subdir),elf)
> +
> +tests-map-32bit = \
> +  tst-map-32bit-1a \
> +  tst-map-32bit-1b \
> +# tests-map-32bit
> +tst-map-32bit-1a-no-pie = yes
> +tst-map-32bit-1b-no-pie = yes
> +tests += $(tests-map-32bit)
> +
> +modules-map-32bit = \
> +  tst-map-32bit-mod \
> +# modules-map-32bit
> +modules-names += $(modules-map-32bit)
> +
> +$(objpfx)tst-map-32bit-mod.so: $(libsupport)
> +tst-map-32bit-1a-ENV = LD_PREFER_MAP_32BIT_EXEC=1
> +$(objpfx)tst-map-32bit-1a: $(objpfx)tst-map-32bit-mod.so
> +tst-map-32bit-1b-ENV = GLIBC_TUNABLES=glibc.cpu.prefer_map_32bit_exec=1
> +$(objpfx)tst-map-32bit-1b: $(objpfx)tst-map-32bit-mod.so
> +
> +endif
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/dl-tunables.list 
> b/sysdeps/x86_64/64/dl-tunables.list
> similarity index 100%
> rename from sysdeps/unix/sysv/linux/x86_64/64/dl-tunables.list
> rename to sysdeps/x86_64/64/dl-tunables.list
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-1a.c 
> b/sysdeps/x86_64/64/tst-map-32bit-1a.c
> similarity index 100%
> rename from sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-1a.c
> rename to sysdeps/x86_64/64/tst-map-32bit-1a.c
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-1b.c 
> b/sysdeps/x86_64/64/tst-map-32bit-1b.c
> similarity index 100%
> rename from sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-1b.c
> rename to sysdeps/x86_64/64/tst-map-32bit-1b.c
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-mod.c 
> b/sysdeps/x86_64/64/tst-map-32bit-mod.c
> similarity index 100%
> rename from sysdeps/unix/sysv/linux/x86_64/64/tst-map-32bit-mod.c
> rename to sysdeps/x86_64/64/tst-map-32bit-mod.c
> -- 
> 2.40.0
> 

-- 
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.