path: root/arch/x86/kernel/jump_label.c
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2013-10-19x86/jump_label: expect default_nop if static_key gets enabled on boot-upHannes Frederic Sowa1-7/+18
net_get_random_once(intrduced in the next patch) uses static_keys in a way that they get enabled on boot-up instead of replaced with an ideal_nop. So check for default_nop on initial enabling. Other architectures don't check for this. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Eric Dumazet <edumazet@google.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: x86@kernel.org Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-11Merge branch 'x86/jumplabel' of ↵Linus Torvalds1-4/+66
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 jumplabel changes from Peter Anvin: "One more x86 tree for this merge window. This tree improves the handling of jump labels, so that most of the time we don't have to do a massive initial patching run. Furthermore, we will error out of the jump label is not what is expected, eg if it has been corrupted or tampered with" * 'x86/jumplabel' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/jump-label: Show where and what was wrong on errors x86/jump-label: Add safety checks to jump label conversions x86/jump-label: Do not bother updating nops if they are correct x86/jump-label: Use best default nops for inital jump label calls
2013-08-07x86/jump-label: Show where and what was wrong on errorsSteven Rostedt1-3/+18
When modifying text sections for jump labels, a paranoid check is performed. If the check fails, the system "bugs". But why it failed is not shown. The BUG_ON()s in the jump label update code is replaced with bug_at(ip). This is a function that will show what pointer failed, and what was at the location of the failure that made jump label panic. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-07x86/jump-label: Add safety checks to jump label conversionsSteven Rostedt1-4/+28
As with all modifying of kernel text, we need to be very paranoid. When converting the jump label locations to and from nops to jumps a check has been added to make sure what we are replacing is what we expect, otherwise we bug. Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jason Baron <jbaron@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-07x86/jump-label: Do not bother updating nops if they are correctSteven Rostedt1-1/+24
On boot up, the jump label init function scans all the jump label locations and converts them to the best nop for the machine. If the nop is already the ideal nop, do not bother with changing it. Cc: Jason Baron <jbaron@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-07-17x86: Make jump_label use int3-based patchingJiri Kosina1-2/+14
Make jump labels use text_poke_bp() for text patching instead of text_poke_smp(), avoiding the need for stop_machine(). Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1307121120250.29788@pobox.suse.cz Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-06jump_label, x86: Fix section mismatchPeter Zijlstra1-1/+1
WARNING: arch/x86/kernel/built-in.o(.text+0x4c71): Section mismatch in reference from the function arch_jump_label_transform_static() to the function .init.text:text_poke_early() The function arch_jump_label_transform_static() references the function __init text_poke_early(). This is often because arch_jump_label_transform_static lacks a __init annotation or the annotation of text_poke_early is wrong. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jason Baron <jbaron@redhat.com> Link: http://lkml.kernel.org/n/tip-9lefe89mrvurrwpqw5h8xm8z@git.kernel.org Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-10-25x86/jump_label: add arch_jump_label_transform_static()Jeremy Fitzhardinge1-3/+17
This allows jump-label entries to be cheaply updated on code which is not yet live. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jason Baron <jbaron@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2011-10-25x86/jump_label: drop arch_jump_label_text_poke_early()Jeremy Fitzhardinge1-6/+0
It is no longer used. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Jason Baron <jbaron@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2011-04-18x86, cpu: Clean up and unify the NOP selection infrastructureH. Peter Anvin1-2/+3
Clean up and unify the NOP selection infrastructure: - Make the atomic 5-byte NOP a part of the selection system. - Pick NOPs once during early boot and then be done with it. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jason Baron <jbaron@redhat.com> Link: http://lkml.kernel.org/r/1303166160-10315-3-git-send-email-hpa@linux.intel.com
2010-09-22jump label: x86 supportJason Baron1-0/+50
add x86 support for jump label. I'm keeping this patch separate so its clear to arch maintainers what was required for x86 support this new feature. Hopefully, it wouldn't be too painful for other archs. Signed-off-by: Jason Baron <jbaron@redhat.com> LKML-Reference: <f838f49f40fbea0254036194be66dc48b598dcea.1284733808.git.jbaron@redhat.com> [ cleaned up some formatting ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

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