kernel/arch/powerpc/include/asm/elf.h, branch linux-4.3.y

mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE

2015-04-14T23:49:05Z

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 Cc: Hector Marco-Gisbert Cc: Russell King Reviewed-by: Ingo Molnar Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Alexander Viro Cc: Oleg Nesterov Cc: Andy Lutomirski Cc: "David A. Long" Cc: Andrey Ryabinin Cc: Arun Chandran Cc: Yann Droneaud Cc: Min-Hua Chen Cc: Paul Burton Cc: Alex Smith Cc: Markos Chandras Cc: Vineeth Vijayan Cc: Jeff Bailey Cc: Michael Holzheu Cc: Ben Hutchings Cc: Behan Webster Cc: Ismael Ripoll Cc: Jan-Simon Mller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc: Use generic PIE randomization

2014-11-17T06:55:11Z

Back in 2009 we merged 501cb16d3cfd "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 [mpe: Rewrite changelog] Signed-off-by: Michael Ellerman

powerpc: Clear ELF personality flag if ELFv2 is not requested.

2014-05-20T00:55:59Z

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 arch/powerpc/include/asm/elf.h | 2 ++ 1 file changed, 2 insertions(+) Signed-off-by: Benjamin Herrenschmidt

powerpc: Set eflags correctly for ELF ABIv2 core dumps.

2013-11-20T22:19:18Z

We leave it at zero (though it could be 1) for old tasks. Signed-off-by: Rusty Russell Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Add TIF_ELF2ABI flag.

2013-11-20T22:19:17Z

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 Signed-off-by: Anton Blanchard Signed-off-by: Benjamin Herrenschmidt

powerpc: Add HWCAP2 aux entry

2013-04-26T06:08:16Z

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 Signed-off-by: Nishanth Aravamudan Signed-off-by: Benjamin Herrenschmidt

default SET_PERSONALITY() in linux/elf.h

2013-02-26T07:46:08Z

Signed-off-by: Al Viro

UAPI: (Scripted) Disintegrate arch/powerpc/include/asm

2012-10-09T08:47:26Z

Signed-off-by: David Howells Acked-by: Arnd Bergmann Acked-by: Thomas Gleixner Acked-by: Michael Kerrisk Acked-by: Paul E. McKenney Acked-by: Dave Jones

treewide: fix potentially dangerous trailing ';' in #defined values/expressions

2011-07-21T12:10:00Z

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: 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 Signed-off-by: Jiri Kosina

powerpc: Use is_32bit_task() helper to test 32-bit binary

2010-09-02T04:07:32Z

This patch removes all explicit tests for the TIF_32BIT flag Signed-off-by: Denis Kirjanov Signed-off-by: Benjamin Herrenschmidt