On Mon, 2019-10-07 at 05:11 -0400, Alex Ghiti wrote: > On 10/4/19 10:12 PM, Atish Patra wrote: > > On Thu, 2019-08-08 at 02:17 -0400, Alexandre Ghiti wrote: > > > In order to avoid wasting user address space by using bottom-up > > > mmap > > > allocation scheme, prefer top-down scheme when possible. > > > > > > Before: > > > root@qemuriscv64:~# cat /proc/self/maps > > > 00010000-00016000 r-xp 00000000 fe:00 > > > 6389 /bin/cat.coreutils > > > 00016000-00017000 r--p 00005000 fe:00 > > > 6389 /bin/cat.coreutils > > > 00017000-00018000 rw-p 00006000 fe:00 > > > 6389 /bin/cat.coreutils > > > 00018000-00039000 rw-p 00000000 00:00 0 [heap] > > > 1555556000-155556d000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so > > > 155556d000-155556e000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so > > > 155556e000-155556f000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so > > > 155556f000-1555570000 rw-p 00000000 00:00 0 > > > 1555570000-1555572000 r-xp 00000000 00:00 0 [vdso] > > > 1555574000-1555576000 rw-p 00000000 00:00 0 > > > 1555576000-1555674000 r-xp 00000000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 1555674000-1555678000 r--p 000fd000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 1555678000-155567a000 rw-p 00101000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 155567a000-15556a0000 rw-p 00000000 00:00 0 > > > 3fffb90000-3fffbb1000 rw-p 00000000 00:00 0 [stack] > > > > > > After: > > > root@qemuriscv64:~# cat /proc/self/maps > > > 00010000-00016000 r-xp 00000000 fe:00 > > > 6389 /bin/cat.coreutils > > > 00016000-00017000 r--p 00005000 fe:00 > > > 6389 /bin/cat.coreutils > > > 00017000-00018000 rw-p 00006000 fe:00 > > > 6389 /bin/cat.coreutils > > > 2de81000-2dea2000 rw-p 00000000 00:00 0 [heap] > > > 3ff7eb6000-3ff7ed8000 rw-p 00000000 00:00 0 > > > 3ff7ed8000-3ff7fd6000 r-xp 00000000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 3ff7fd6000-3ff7fda000 r--p 000fd000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 3ff7fda000-3ff7fdc000 rw-p 00101000 fe:00 7187 /lib/libc- > > > 2.28.so > > > 3ff7fdc000-3ff7fe2000 rw-p 00000000 00:00 0 > > > 3ff7fe4000-3ff7fe6000 r-xp 00000000 00:00 0 [vdso] > > > 3ff7fe6000-3ff7ffd000 r-xp 00000000 fe:00 7193 /lib/ld-2.28.so > > > 3ff7ffd000-3ff7ffe000 r--p 00016000 fe:00 7193 /lib/ld-2.28.so > > > 3ff7ffe000-3ff7fff000 rw-p 00017000 fe:00 7193 /lib/ld-2.28.so > > > 3ff7fff000-3ff8000000 rw-p 00000000 00:00 0 > > > 3fff888000-3fff8a9000 rw-p 00000000 00:00 0 [stack] > > > > > > Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx> > > > Acked-by: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > > > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > > > Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> > > > Reviewed-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> > > > --- > > > arch/riscv/Kconfig | 12 ++++++++++++ > > > 1 file changed, 12 insertions(+) > > > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > > index 59a4727ecd6c..87dc5370becb 100644 > > > --- a/arch/riscv/Kconfig > > > +++ b/arch/riscv/Kconfig > > > @@ -54,6 +54,18 @@ config RISCV > > > select EDAC_SUPPORT > > > select ARCH_HAS_GIGANTIC_PAGE > > > select ARCH_WANT_HUGE_PMD_SHARE if 64BIT > > > + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU > > > + select HAVE_ARCH_MMAP_RND_BITS > > > + > > > +config ARCH_MMAP_RND_BITS_MIN > > > + default 18 if 6legacy_va_layout4BIT > > > + default 8 > > > + > > > +# max bits determined by the following formula: > > > +# VA_BITS - PAGE_SHIFT - 3 > > > +config ARCH_MMAP_RND_BITS_MAX > > > + default 24 if 64BIT # SV39 based > > > + default 17 > > > > > > config MMU > > > def_bool y > > With this patch, I am not able to boot a Fedora Linux(a Gnome > > desktop > > image) on RISC-V hardware (Unleashed + Microsemi Expansion board). > > The > > booting gets stuck right after systemd starts. > > > > https://paste.fedoraproject.org/paste/TOrUMqqKH-pGFX7CnfajDg > > > > Reverting just this patch allow to boot Fedora successfully on > > specific > > RISC-V hardware. I have not root caused the issue but it looks like > > it > > might have messed userpsace mapping. > > It might have messed userspace mapping but not enough to make > userspace > completely broken > as systemd does some things. I would try to boot in legacy layout: > if > you can try to set sysctl legacy_va_layout > at boottime, it will map userspace as it was before (bottom-up). If > that > does not work, the problem could > be the randomization that is activated by default now. Randomization may not be the issue. I just removed ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT from the config and that seems to work. Here is the bottom-up layout with randomization on. [root@fedora-riscv ~]# cat /proc/self/maps 1555556000-1555570000 r-xp 00000000 103:01 280098 /usr/lib64/ld-2.28.so 1555570000-1555571000 r--p 00019000 103:01 280098 /usr/lib64/ld-2.28.so 1555571000-1555572000 rw-p 0001a000 103:01 280098 /usr/lib64/ld-2.28.so 1555572000-1555573000 rw-p 00000000 00:00 0 1555573000-1555575000 r-xp 00000000 00:00 0 [vdso] 1555575000-1555576000 r--p 00000000 103:01 50936 /usr/lib/locale/en_US.utf8/LC_IDENTIFICAT ION 1555576000-155557d000 r--s 00000000 103:01 280826 /usr/lib64/gconv/gconv-modules.cache 155557d000-155557e000 r--p 00000000 103:01 50937 /usr/lib/locale/en_US.utf8/LC_MEASUREMENT 155557e000-155557f000 r--p 00000000 103:01 50939 /usr/lib/locale/en_US.utf8/LC_TELEPHONE 155557f000-1555580000 r--p 00000000 103:01 3706 /usr/lib/locale/en_US.utf8/LC_ADDRESS 1555580000-1555581000 r--p 00000000 103:01 50944 /usr/lib/locale/en_US.utf8/LC_NAME 1555581000-1555582000 r--p 00000000 103:01 3775 /usr/lib/locale/en_US.utf8/LC_PAPER 1555582000-1555583000 r--p 00000000 103:01 3758 /usr/lib/locale/en_US.utf8/LC_MESSAGES/SY S_LC_MESSAGES 1555583000-1555584000 r--p 00000000 103:01 50938 /usr/lib/locale/en_US.utf8/LC_MONETARY 1555584000-1555585000 r--p 00000000 103:01 50940 /usr/lib/locale/en_US.utf8/LC_TIME 1555585000-1555586000 r--p 00000000 103:01 50945 /usr/lib/locale/en_US.utf8/LC_NUMERIC 1555590000-1555592000 rw-p 00000000 00:00 0 1555592000-15556b1000 r-xp 00000000 103:01 280105 /usr/lib64/libc-2.28.so 15556b1000-15556b5000 r--p 0011e000 103:01 280105 /usr/lib64/libc-2.28.so 15556b5000-15556b7000 rw-p 00122000 103:01 280105 /usr/lib64/libc-2.28.so 15556b7000-15556bb000 rw-p 00000000 00:00 0 15556bb000-1555933000 r--p 00000000 103:01 3755 /usr/lib/locale/en_US.utf8/LC_COLLATE 1555933000-1555986000 r--p 00000000 103:01 50942 /usr/lib/locale/en_US.utf8/LC_CTYPE 1555986000-15559a8000 rw-p 00000000 00:00 0 2aaaaaa000-2aaaab1000 r-xp 00000000 103:01 283975 /usr/bin/cat 2aaaab1000-2aaaab2000 r--p 00006000 103:01 283975 /usr/bin/cat 2aaaab2000-2aaaab3000 rw-p 00007000 103:01 283975 /usr/bin/cat 2aaaab3000-2aaaad4000 rw-p 00000000 00:00 0 [heap] 3fffc97000-3fffcb8000 rw-p 00000000 00:00 0 [stack] > Anyway, it's weird since userspace should not depend on how the > mapping is. > > If you can identify the program that stalls, that would be fantastic > :) > It stucks while booting. So I am not sure how to figure out which program stalls. It is difficult to figure out from boot log as it stucks at different places but soon after systemd starts. > As the code is common to mips and arm now and I did not hear from > them, > I imagine the problem comes > from us. > > Alex -- Regards, Atish
