Now that explicitly executed loaders are loaded in the mmap region, we
have more freedom to decide where we position PIE binaries in the
address space to avoid possible collisions with mmap or stack regions.
For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit
address space for 32-bit pointers. On 32-bit use 4MB, which is the
traditional x86 minimum load location, likely to avoid historically
requiring a 4MB page table entry when only a portion of the first 4MB
would be used (since the NULL address is avoided).
Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It seems we didn't pay quite enough attention when testing the new cache
shape vectors, which means we didn't notice the bug where the vector for
the L1D was using the L1I values. Fix it, resulting in eg:
L1I cache size: 0x8000 32768B 32K
L1I line size: 0x80 8-way associative
L1D cache size: 0x10000 65536B 64K
L1D line size: 0x80 8-way associative
Fixes: 98a5f361b8 ("powerpc: Add new cache geometry aux vectors")
Cut-and-paste-bug-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Badly-reviewed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds AUX vectors for the L1I,D, L2 and L3 cache levels
providing for each cache level the size of the cache in bytes
and the geometry (line size and number of ways).
We chose to not use the existing alpha/sh definition which
packs all the information in a single entry per cache level as
it is too restricted to represent some of the geometries used
on POWER.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It's an kernel private macro, it doesn't belong there
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The arch_randomize_brk() function is used on several architectures,
even those that don't support ET_DYN ASLR. To avoid bulky extern/#define
tricks, consolidate the support under CONFIG_ARCH_HAS_ELF_RANDOMIZE for
the architectures that support it, while still handling CONFIG_COMPAT_BRK.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Hector Marco-Gisbert <hecmargi@upv.es>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Arun Chandran <achandran@mvista.com>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Min-Hua Chen <orca.chen@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Vineeth Vijayan <vvijayan@mvista.com>
Cc: Jeff Bailey <jeffbailey@google.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Behan Webster <behanw@converseincode.com>
Cc: Ismael Ripoll <iripoll@upv.es>
Cc: Jan-Simon Mller <dl9pf@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Back in 2009 we merged 501cb16d3c "Randomise PIEs", which added support for
randomizing PIE (Position Independent Executable) binaries.
That commit added randomize_et_dyn(), which correctly randomized the addresses,
but failed to honor PF_RANDOMIZE. That means it was not possible to disable PIE
randomization via the personality flag, or /proc/sys/kernel/randomize_va_space.
Since then there has been generic support for PIE randomization added to
binfmt_elf.c, selectable via ARCH_BINFMT_ELF_RANDOMIZE_PIE.
Enabling that allows us to drop randomize_et_dyn(), which means we start
honoring PF_RANDOMIZE correctly.
It also causes a fairly major change to how we layout PIE binaries.
Currently we will place the binary at 512MB-520MB for 32 bit binaries, or
512MB-1.5GB for 64 bit binaries, eg:
$ cat /proc/$$/maps
4e550000-4e580000 r-xp 00000000 08:02 129813 /bin/dash
4e580000-4e590000 rw-p 00020000 08:02 129813 /bin/dash
10014110000-10014140000 rw-p 00000000 00:00 0 [heap]
3fffaa3f0000-3fffaa5a0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fffaa5a0000-3fffaa5b0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fffaa5c0000-3fffaa5d0000 rw-p 00000000 00:00 0
3fffaa5d0000-3fffaa5f0000 r-xp 00000000 00:00 0 [vdso]
3fffaa5f0000-3fffaa620000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fffaa620000-3fffaa630000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3ffffc340000-3ffffc370000 rw-p 00000000 00:00 0 [stack]
With this commit applied we don't do any special randomisation for the binary,
and instead rely on mmap randomisation. This means the binary ends up at high
addresses, eg:
$ cat /proc/$$/maps
3fff99820000-3fff999d0000 r-xp 00000000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fff999d0000-3fff999e0000 rw-p 001a0000 08:02 921 /lib/powerpc64le-linux-gnu/libc-2.19.so
3fff999f0000-3fff99a00000 rw-p 00000000 00:00 0
3fff99a00000-3fff99a20000 r-xp 00000000 00:00 0 [vdso]
3fff99a20000-3fff99a50000 r-xp 00000000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fff99a50000-3fff99a60000 rw-p 00020000 08:02 1246 /lib/powerpc64le-linux-gnu/ld-2.19.so
3fff99a60000-3fff99a90000 r-xp 00000000 08:02 129813 /bin/dash
3fff99a90000-3fff99aa0000 rw-p 00020000 08:02 129813 /bin/dash
3fffc3de0000-3fffc3e10000 rw-p 00000000 00:00 0 [stack]
3fffc55e0000-3fffc5610000 rw-p 00000000 00:00 0 [heap]
Although this should be OK, it's possible it might break badly written
binaries that make assumptions about the address space layout.
Signed-off-by: Vineeth Vijayan <vvijayan@mvista.com>
[mpe: Rewrite changelog]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
powerpc: Clear ELF personality flag if ELFv2 is not requested.
The POWER kernel uses a personality flag to determine whether it should
be setting up function descriptors or not (per the updated ABI). This
flag wasn't being cleared on a new process but instead was being
inherited. The visible effect was that an ELFv2 binary could not execve
to an ELFv1 binary.
Signed-off-by: Jeff Bailey <jeffbailey@google.com>
arch/powerpc/include/asm/elf.h | 2 ++
1 file changed, 2 insertions(+)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We leave it at zero (though it could be 1) for old tasks.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Little endian ppc64 is getting an exciting new ABI. This is reflected
by the bottom two bits of e_flags in the ELF header:
0 == legacy binaries (v1 ABI)
1 == binaries using the old ABI (compiled with a new toolchain)
2 == binaries using the new ABI.
We store this in a thread flag, because we need to set it in core
dumps and for signal delivery. Our chief concern is that it doesn't
use function descriptors.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We are currently out of free bits in AT_HWCAP. With POWER8, we have
several hardware features that we need to advertise.
Tested on POWER and x86.
Signed-off-by: Michael Neuling <michael@neuling.org>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
All these are instances of
#define NAME value;
or
#define NAME(params_opt) value;
These of course fail to build when used in contexts like
if(foo $OP NAME)
while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
foo = NAME + 1; /* foo = value; + 1; */
bar = NAME - 1; /* bar = value; - 1; */
baz = NAME & quux; /* baz = value; & quux; */
Reported on comp.lang.c,
Message-ID: <ab0d55fe-25e5-482b-811e-c475aa6065c3@c29g2000yqd.googlegroups.com>
Initial analysis of the dangers provided by Keith Thompson in that thread.
There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This patch removes all explicit tests for the TIF_32BIT flag
Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Here are the powerpc bits to remove TIF_ABI_PENDING now that
set_personality() is called at the appropriate place in exec.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Currently all architectures but microblaze unconditionally define
USE_ELF_CORE_DUMP. The microblaze omission seems like an error to me, so
let's kill this ifdef and make sure we are the same everywhere.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: <linux-arch@vger.kernel.org>
Cc: Michal Simek <michal.simek@petalogix.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We believe if a toolchain supports PT_GNU_STACK that it sets the proper
PHDR permissions. Therefor elf_read_implies_exec() should only be true
if we don't see PT_GNU_STACK set.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
On ppc64 we implemented elf_read_implies_exec() for 32-bit binaries
because old toolchains had bugs where they didn't mark program
segments executable that needed to be. For some reason we didn't do
this on ppc32 builds. This hadn't been an issue until commit 8d30c14c
("powerpc/mm: Rework I$/D$ coherency (v3)"), which had as a side
effect that we are now enforcing execute permissions to some extent on
32-bit 4xx and Book E processors.
This fixes it by defining elf_read_implies_exec on 32-bit to turn on
the read-implies-exec behaviour on programs that are sufficiently old
that they don't have a PT_GNU_STACK program header.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Now that ppc32 implements address randomization it also wants to inherit
personality flags like ADDR_NO_RANDOMIZE across exec, for things like
`setarch ppc -R' to work. But the ppc32 version of SET_PERSONALITY
forcefully sets PER_LINUX, clearing all personality flags. So be
careful about preserving the flags.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Randomise ELF_ET_DYN_BASE, which is used when loading position independent
executables.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
At the moment we randomise the stack by 8MB on 32bit and 64bit tasks. Since we
have a lot more address space to play with on 64bit, lets do what x86 does and
increase that randomisation to 1GB:
before:
# for i in seq `1 10` ; do sleep 1 & cat /proc/${!}/maps | grep stack; done
fffffebc000-fffffed1000 rw-p ffffffeb000 00:00 0 [stack]
ffffff5a000-ffffff6f000 rw-p ffffffeb000 00:00 0 [stack]
fffffdb2000-fffffdc7000 rw-p ffffffeb000 00:00 0 [stack]
fffffd3e000-fffffd53000 rw-p ffffffeb000 00:00 0 [stack]
fffffad9000-fffffaee000 rw-p ffffffeb000 00:00 0 [stack]
after:
# for i in seq `1 10` ; do sleep 1 & cat /proc/${!}/maps | grep stack; done
ffff5c27000-ffff5c3c000 rw-p ffffffeb000 00:00 0 [stack]
fffebe5e000-fffebe73000 rw-p ffffffeb000 00:00 0 [stack]
fffcb298000-fffcb2ad000 rw-p ffffffeb000 00:00 0 [stack]
fffc719d000-fffc71b2000 rw-p ffffffeb000 00:00 0 [stack]
fffe01af000-fffe01c4000 rw-p ffffffeb000 00:00 0 [stack]
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
include/asm/bootx.h:12: include of <linux/types.h> is preferred over <asm/types.h>
include/asm/bootx.h:57: found __[us]{8,16,32,64} type without #include <linux/types.h>
include/asm/elf.h:5: include of <linux/types.h> is preferred over <asm/types.h>
include/asm/kvm.h:23: include of <linux/types.h> is preferred over <asm/types.h>
include/asm/kvm.h:26: found __[us]{8,16,32,64} type without #include <linux/types.h>
include/asm/ps3fb.h:33: found __[us]{8,16,32,64} type without #include <linux/types.h>
include/asm/spu_info.h:27: found __[us]{8,16,32,64} type without #include <linux/types.h>
include/asm/swab.h:11: include of <linux/types.h> is preferred over <asm/types.h>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
arch_setup_additional_pages currently gets two arguments, the binary
format descripton and an indication if the process uses an executable
stack or not. The second argument is not used by anybody, it could
be removed without replacement.
What actually does make sense is to pass an indication if the process
uses the elf interpreter or not. The glibc code will not use anything
from the vdso if the process does not use the dynamic linker, so for
statically linked binaries the architecture backend can choose not
to map the vdso.
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The SET_PERSONALITY macro is always called with a second argument of 0.
Remove the ibcs argument and the various tests to set the PER_SVR4
personality.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Commit deac93df26 ("lib: Correct printk
%pF to work on all architectures") broke the non modular builds by
moving an essential function into modules.c. Fix this by moving it
out again and into asm/sections.h as an inline. To do this, the
definition of struct ppc64_opd_entry has been lifted out of modules.c
and put in asm/elf.h where it belongs.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
from include/asm-powerpc. This is the result of a
mkdir arch/powerpc/include/asm
git mv include/asm-powerpc/* arch/powerpc/include/asm
Followed by a few documentation/comment fixups and a couple of places
where <asm-powepc/...> was being used explicitly. Of the latter only
one was outside the arch code and it is a driver only built for powerpc.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Kees Cook