| Message ID | 20200519185645.3915-3-richard.henderson@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | linux-user: mmap/mprotect prot values | expand |
On 5/19/20 8:56 PM, Richard Henderson wrote: > Executable guest pages are never directly executed by > the host, but do need to be readable for translation. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/mmap.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/linux-user/mmap.c b/linux-user/mmap.c > index 36fd1e2250..84662c3311 100644 > --- a/linux-user/mmap.c > +++ b/linux-user/mmap.c > @@ -76,8 +76,12 @@ static int validate_prot_to_pageflags(int *host_prot, int prot) > * don't bother transforming guest bit to host bit. Any other > * target-specific prot bits will not be understood by the host > * and will need to be encoded into page_flags for qemu emulation. > + * > + * Pages that are executable by the guest will never be executed > + * by the host, but the host will need to be able to read them. > */ > - *host_prot = prot & (PROT_READ | PROT_WRITE | PROT_EXEC); > + *host_prot = (prot & (PROT_READ | PROT_WRITE)) > + | (prot & PROT_EXEC ? PROT_READ : 0); > > return prot & ~valid ? 0 : page_flags; > } > Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
On Tue, 19 May 2020 at 19:57, Richard Henderson <richard.henderson@linaro.org> wrote: > > Executable guest pages are never directly executed by > the host, but do need to be readable for translation. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/mmap.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > Reviewed-by: Peter Maydell <peter.maydell@linaro.org> thanks -- PMM
Le 19/05/2020 à 20:56, Richard Henderson a écrit : > Executable guest pages are never directly executed by > the host, but do need to be readable for translation. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > linux-user/mmap.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/linux-user/mmap.c b/linux-user/mmap.c > index 36fd1e2250..84662c3311 100644 > --- a/linux-user/mmap.c > +++ b/linux-user/mmap.c > @@ -76,8 +76,12 @@ static int validate_prot_to_pageflags(int *host_prot, int prot) > * don't bother transforming guest bit to host bit. Any other > * target-specific prot bits will not be understood by the host > * and will need to be encoded into page_flags for qemu emulation. > + * > + * Pages that are executable by the guest will never be executed > + * by the host, but the host will need to be able to read them. > */ > - *host_prot = prot & (PROT_READ | PROT_WRITE | PROT_EXEC); > + *host_prot = (prot & (PROT_READ | PROT_WRITE)) > + | (prot & PROT_EXEC ? PROT_READ : 0); > > return prot & ~valid ? 0 : page_flags; > } > Applied to my linux-user-for-5.2 branch. Thanks, Laurent
diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 36fd1e2250..84662c3311 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -76,8 +76,12 @@ static int validate_prot_to_pageflags(int *host_prot, int prot) * don't bother transforming guest bit to host bit. Any other * target-specific prot bits will not be understood by the host * and will need to be encoded into page_flags for qemu emulation. + * + * Pages that are executable by the guest will never be executed + * by the host, but the host will need to be able to read them. */ - *host_prot = prot & (PROT_READ | PROT_WRITE | PROT_EXEC); + *host_prot = (prot & (PROT_READ | PROT_WRITE)) + | (prot & PROT_EXEC ? PROT_READ : 0); return prot & ~valid ? 0 : page_flags; }
Executable guest pages are never directly executed by the host, but do need to be readable for translation. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- linux-user/mmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 2.20.1