Re: [PATCH] linux-user: Fix executable page of /proc/self/maps

[Richard Henderson]

On 3/5/21 9:31 AM, Nicolas Surbayrole wrote:
> The guest binary and libraries are not always mapped with the
> executable bit in the host process. The guest may read a
> /proc/self/maps with no executable address range. The
> patch bases the perm fields against the guest permission inside
> Qemu.
>
> Signed-off-by: Nicolas Surbayrole <nsurbayrole@quarkslab.com>
> ---
>   linux-user/syscall.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 389ec09764..77c40a274f 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -7888,9 +7888,9 @@ static int open_self_maps(void *cpu_env, int fd)
>               count = dprintf(fd, TARGET_ABI_FMT_ptr "-" TARGET_ABI_FMT_ptr
>                               " %c%c%c%c %08" PRIx64 " %s %"PRId64,
>                               h2g(min), h2g(max - 1) + 1,
> -                            e->is_read ? 'r' : '-',
> -                            e->is_write ? 'w' : '-',
> -                            e->is_exec ? 'x' : '-',
> +                            (flags & PROT_READ) ? 'r' : '-',
> +                            (flags & PROT_WRITE) ? 'w' : '-',
> +                            (flags & PROT_EXEC) ? 'x' : '-',

Use PAGE_*, as those are the bits in flags.  These three just happen to be the 
same.

While we're at it, use PAGE_WRITE_ORG -- PAGE_WRITE may be removed on a rwx 
page in which we've translated code.


r~



>                               e->is_priv ? 'p' : '-',
>                               (uint64_t) e->offset, e->dev, e->inode);
>               if (path) {