linux/arch/x86/kernel
Jiri Kosina c1d171a002 x86: randomize brk
Randomize the location of the heap (brk) for i386 and x86_64.  The range is
randomized in the range starting at current brk location up to 0x02000000
offset for both architectures.  This, together with
pie-executable-randomization.patch and
pie-executable-randomization-fix.patch, should make the address space
randomization on i386 and x86_64 complete.

Arjan says:

This is known to break older versions of some emacs variants, whose dumper
code assumed that the last variable declared in the program is equal to the
start of the dynamically allocated memory region.

(The dumper is the code where emacs effectively dumps core at the end of it's
compilation stage; this coredump is then loaded as the main program during
normal use)

iirc this was 5 years or so; we found this way back when I was at RH and we
first did the security stuff there (including this brk randomization).  It
wasn't all variants of emacs, and it got fixed as a result (I vaguely remember
that emacs already had code to deal with it for other archs/oses, just
ifdeffed wrongly).

It's a rare and wrong assumption as a general thing, just on x86 it mostly
happened to be true (but to be honest, it'll break too if gcc does
something fancy or if the linker does a non-standard order).  Still its
something we should at least document.

Note 2: afaik it only broke the emacs *build*.  I'm not 100% sure about that
(it IS 5 years ago) though.

[ akpm@linux-foundation.org: deuglification ]

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30 13:30:40 +01:00
..
acpi ACPI: suspend: old debugging hacks sneaked back 2007-12-06 16:03:06 -05:00
cpu x86: extended interrupt LVT support for AMD Barcelona 2008-01-30 13:30:40 +01:00
.gitignore .gitignore update for x86 arch 2007-10-17 21:19:04 +02:00
alternative.c x86: convert cpuinfo_x86 array to a per_cpu array 2007-10-19 20:35:04 +02:00
aperture_64.c x86: clean up arch/x86/kernel/aperture_64.c printk()s 2008-01-30 13:30:10 +01:00
apic_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
apic_64.c x86: extended interrupt LVT support for AMD Barcelona 2008-01-30 13:30:40 +01:00
apm_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
asm-offsets_32.c x86: irqflags consolidation 2008-01-30 13:30:33 +01:00
asm-offsets_64.c x86: remove unused tsk_thread from asm-offsets_64.c 2008-01-30 13:30:39 +01:00
asm-offsets.c i386: move kernel 2007-10-11 11:17:01 +02:00
audit_64.c x86_64: move kernel 2007-10-11 11:17:24 +02:00
bootflag.c i386: move kernel 2007-10-11 11:17:01 +02:00
bugs_64.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
cpuid.c PM: Acquire device locks on suspend 2008-01-24 20:40:04 -08:00
crash_dump_32.c kmap leak fix for x86_32 kdump 2007-10-19 11:53:33 -07:00
crash_dump_64.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
crash.c x86: disable hpet legacy replacement for kdump 2007-12-03 17:17:10 +01:00
doublefault_32.c i386: move kernel 2007-10-11 11:17:01 +02:00
e820_32.c x86: remove extern declarations for code, data, bss resources 2008-01-30 13:30:32 +01:00
e820_64.c x86: remove extern declarations for code, data, bss resources 2008-01-30 13:30:32 +01:00
early_printk.c [x86] remove uses of magic macros for boot_params access 2007-10-16 17:38:31 -07:00
early-quirks.c x86 gart: rename symbols only used for the GART implementation 2007-10-30 00:22:22 +01:00
efi_32.c kexec: add BSS to resource tree 2007-10-22 08:13:19 -07:00
efi_stub_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
entry_32.S x86: irqflags consolidation 2008-01-30 13:30:33 +01:00
entry_64.S sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
genapic_64.c x86: convert cpu_to_apicid to be a per cpu variable 2007-10-19 20:35:03 +02:00
genapic_flat_64.c x86: convert cpu_to_apicid to be a per cpu variable 2007-10-19 20:35:03 +02:00
geode_32.c x86: Geode Multi-Function General Purpose Timers support 2007-10-12 23:04:06 +02:00
head64.c x86: remove duplicate start_kernel declaration 2008-01-30 13:30:19 +01:00
head_32.S fix lguest rmmod "bad pgd" 2008-01-01 11:30:35 -08:00
head_64.S x86_64: move kernel 2007-10-11 11:17:24 +02:00
hpet.c x86: remove duplicate includes 2008-01-30 13:30:32 +01:00
i386_ksyms_32.c x86: unexport __{read,write}_lock_failed 2008-01-30 13:30:29 +01:00
i387_32.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
i387_64.c x86: fix taking DNA during 64bit sigreturn 2007-11-12 11:09:33 -08:00
i8237.c Driver core: change sysdev classes to use dynamic kobject names 2008-01-24 20:40:40 -08:00
i8253.c x86: unregister PIT clocksource when PIT is disabled 2008-01-30 13:30:03 +01:00
i8259_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
i8259_64.c x86: make i8259_64 more _32-like 2008-01-30 13:30:29 +01:00
init_task.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
io_apic_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
io_apic_64.c x86: clear IO_APIC before enabing apic error vector. 2008-01-30 13:30:39 +01:00
io_delay.c x86: add DMI quirk for io-delay hangs on Compaq Presario V6000 laptops 2008-01-30 13:30:05 +01:00
ioport_32.c x86: clean up ioport_32.c 2008-01-30 13:30:24 +01:00
ioport_64.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
irq_32.c x86: also show non-zero IRQ counts for vectors that currently don't have a handler 2007-10-17 20:16:54 +02:00
irq_64.c x86: move ack_bad_irq into irq code 2008-01-30 13:30:19 +01:00
k8.c x86_64: move kernel 2007-10-11 11:17:24 +02:00
kprobes_32.c x86: jprobe bugfix 2007-12-18 18:05:58 +01:00
kprobes_64.c x86: kprobes bugfix 2007-12-18 18:05:58 +01:00
ldt.c x86: merge arch/x86/kernel/ldt_32/64.c 2008-01-30 13:30:14 +01:00
machine_kexec_32.c Use extended crashkernel command line on i386 2007-10-19 11:53:49 -07:00
machine_kexec_64.c x86: Dump filtering supports x86_64 sparsemem 2007-10-27 20:57:43 +02:00
Makefile x86: delete vsyscall files during make clean 2007-10-17 21:56:01 +02:00
Makefile_32 x86: isolate the rtc code for sharing 2008-01-30 13:30:26 +01:00
Makefile_64 x86: share rtc code 2008-01-30 13:30:27 +01:00
mca_32.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
mfgpt_32.c x86: GEODE fix a race condition in the MFGPT timer tick 2008-01-22 23:30:16 +01:00
microcode.c cpu-hotplug: replace lock_cpu_hotplug() with get_online_cpus() 2008-01-25 21:08:02 +01:00
module_32.c i386: move kernel 2007-10-11 11:17:01 +02:00
module_64.c x86_64: move kernel 2007-10-11 11:17:24 +02:00
mpparse_32.c x86: cleanup mpspec variants 2008-01-30 13:30:35 +01:00
mpparse_64.c x86: acpi use cpu_physical_id 2007-10-19 20:35:03 +02:00
msr.c PM: Acquire device locks on suspend 2008-01-24 20:40:04 -08:00
nmi_32.c x86: clean up nmi_32/64.c 2008-01-30 13:30:33 +01:00
nmi_64.c x86: clean up nmi_32/64.c 2008-01-30 13:30:33 +01:00
numaq_32.c i386: move kernel 2007-10-11 11:17:01 +02:00
paravirt_32.c x86: irqflags consolidation 2008-01-30 13:30:33 +01:00
pci-calgary_64.c x86: remove duplicate includes 2008-01-30 13:30:32 +01:00
pci-dma_32.c i386: Clean up duplicate includes in arch/i386/kernel/ 2007-10-17 20:15:51 +02:00
pci-dma_64.c x86: pci-dma_64.c: cleanups 2008-01-30 13:30:31 +01:00
pci-gart_64.c x86: code cleanups in arch/x86/kernel/pci-gart_64.c 2008-01-30 13:30:12 +01:00
pci-nommu_64.c x86 gart: rename iommu.h to gart.h 2007-10-30 00:22:22 +01:00
pci-swiotlb_64.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
pcspeaker.c i386: move kernel 2007-10-11 11:17:01 +02:00
pmtimer_64.c x86: move pmtmr related declarations 2008-01-30 13:30:18 +01:00
process_32.c x86: randomize brk 2008-01-30 13:30:40 +01:00
process_64.c x86: randomize brk 2008-01-30 13:30:40 +01:00
ptrace_32.c spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
ptrace_64.c x86: convert mm_context_t semaphore to a mutex 2007-10-17 20:17:00 +02:00
quirks.c x86: Add HPET force support for MCP55 (nForce 5) chipsets 2007-10-23 22:37:25 +02:00
reboot_32.c x86: disable hpet on shutdown 2007-12-03 17:17:10 +01:00
reboot_64.c x86: disable hpet on shutdown 2007-12-03 17:17:10 +01:00
reboot_fixups_32.c x86: reboot fixup for wrap2c board 2007-11-17 16:27:02 +01:00
relocate_kernel_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
relocate_kernel_64.S x86_64: move kernel 2007-10-11 11:17:24 +02:00
rtc.c x86: share rtc code 2008-01-30 13:30:27 +01:00
scx200_32.c long vs. unsigned long - low-hanging fruits in drivers 2007-10-14 12:41:51 -07:00
setup64.c x86: use descriptor's functions instead of inline assembly 2007-10-19 20:35:03 +02:00
setup_32.c x86: remove extern declarations for code, data, bss resources 2008-01-30 13:30:32 +01:00
setup_64.c x86: store core id bits in cpuinfo_x8 2008-01-30 13:30:39 +01:00
sigframe_32.h i386: move kernel 2007-10-11 11:17:01 +02:00
signal_32.c x86: protect against sigaltstack wraparound 2008-01-30 13:30:06 +01:00
signal_64.c sched: high-res preemption tick 2008-01-25 21:08:29 +01:00
smp_32.c x86: export smp_ops to allow modular build of KVM 2007-10-27 20:57:43 +02:00
smp_64.c x86: cleanup tlbflush.h variants 2008-01-30 13:30:35 +01:00
smpboot_32.c x86: adjust numa 32 namespace 2008-01-30 13:30:38 +01:00
smpboot_64.c x86: untable __init references between IO data 2008-01-30 13:30:40 +01:00
smpcommon_32.c i386: move kernel 2007-10-11 11:17:01 +02:00
srat_32.c i386: move kernel 2007-10-11 11:17:01 +02:00
stacktrace.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
summit_32.c spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
suspend_64.c x86: hibernation: document __save_processor_state() on x86 2008-01-30 13:30:04 +01:00
suspend_asm_64.S x86: Save registers in saved_context during suspend and hibernation 2007-10-23 22:37:24 +02:00
sys_i386_32.c remove include/asm-*/ipc.h 2007-10-17 08:42:55 -07:00
sys_x86_64.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
syscall_64.c i386/x86_64: move headers to include/asm-x86 2007-10-11 11:20:03 +02:00
syscall_table_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
sysenter_32.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
tce_64.c x86: Create clflush() inline, remove hardcoded wbinvd 2007-10-17 20:16:12 +02:00
time_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
time_64.c x86: clean up arch/x86/kernel/time_64.c includes 2008-01-30 13:30:27 +01:00
topology.c x86: arch_register_cpu() section fix 2007-12-04 17:19:07 +01:00
trampoline_32.S x86: misc. constifications 2007-10-17 20:16:08 +02:00
trampoline_64.S x86: misc. constifications 2007-10-17 20:16:08 +02:00
traps_32.c lockdep: more hardirq annotations for notify_die() 2008-01-16 09:51:59 +01:00
traps_64.c x86: nuke a ton of unused exports 2008-01-30 13:30:28 +01:00
tsc_32.c x86: scale cyc_2_nsec according to CPU frequency 2008-01-30 13:30:06 +01:00
tsc_64.c x86: scale cyc_2_nsec according to CPU frequency 2008-01-30 13:30:06 +01:00
tsc_sync.c x86: fix: s2ram + P4 + tsc = annoyance 2008-01-30 13:30:04 +01:00
verify_cpu_64.S x86_64: move kernel 2007-10-11 11:17:24 +02:00
vm86_32.c Delete filenames in comments. 2007-10-13 10:01:23 -07:00
vmi_32.c x86: irqflags consolidation 2008-01-30 13:30:33 +01:00
vmiclock_32.c x86: move 8259 defines to i8259.h 2008-01-30 13:30:29 +01:00
vmlinux_32.lds.S all archs: consolidate init and exit sections in vmlinux.lds.h 2008-01-28 23:21:17 +01:00
vmlinux_64.lds.S all archs: consolidate init and exit sections in vmlinux.lds.h 2008-01-28 23:21:17 +01:00
vmlinux.lds.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsmp_64.c x86: clean up arch/x86/kernel/vsmp_64.c 2008-01-30 13:30:24 +01:00
vsyscall_32.lds.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsyscall_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsyscall_64.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial 2007-10-19 20:36:17 -07:00
vsyscall-int80_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsyscall-note_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsyscall-sigreturn_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
vsyscall-sysenter_32.S i386: move kernel 2007-10-11 11:17:01 +02:00
x8664_ksyms_64.c x86: unexport __{read,write}_lock_failed 2008-01-30 13:30:29 +01:00