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From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Andy Lutomirski <luto@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Brian Gerst <brgerst@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Nilay Vaish <nilayvaish@gmail.com>
Subject: [PATCH 0/9] x86/entry/head: standardize the end of the stack
Date: Tue, 20 Sep 2016 15:02:42 -0500	[thread overview]
Message-ID: <cover.1474400222.git.jpoimboe@redhat.com> (raw)

Thanks to all the recent x86 entry code refactoring, most tasks' kernel
stacks start at the same offset right below their saved pt_regs,
regardless of which syscall was used to enter the kernel.  That creates
a nice convention which makes it straightforward to identify the end of
the stack, which can be useful [*] for the unwinder.

But there a few places where tasks don't yet follow the convention.
This patch set finishes the job.

[*] This will be useful for three upcoming proposed features:

- Detecting corrupt stacks in the unwinder (which will also be a force
  for ensuring this end of stack convention continues to be followed in
  the future).

- Printing all saved pt_regs on the stack during an oops/warning.

- Validating stacks in the livepatch consistency model.


Josh Poimboeuf (9):
  x86/entry/head/32: use local labels
  x86/entry/32: rename 'error_code' to 'common_exception'
  x86/entry/32: fix the end of the stack for newly forked tasks
  x86/head/32: fix the end of the stack for idle tasks
  x86/smp: fix initial idle stack location on 32-bit
  x86/asm/head: use a common function for starting CPUs
  x86/head: put real return address on idle task stack
  x86/head: fix the end of the stack for idle tasks
  x86: move _stext marker to before head code

 arch/x86/entry/entry_32.S     | 120 ++++++++++++++++++++++++------------------
 arch/x86/kernel/head_32.S     |  49 ++++++++++-------
 arch/x86/kernel/head_64.S     |  42 +++++++--------
 arch/x86/kernel/smpboot.c     |   4 +-
 arch/x86/kernel/vmlinux.lds.S |   2 +-
 5 files changed, 122 insertions(+), 95 deletions(-)

-- 
2.7.4

             reply	other threads:[~2016-09-20 20:03 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-20 20:02 Josh Poimboeuf [this message]
2016-09-20 20:02 ` [PATCH 1/9] x86/entry/head/32: use local labels Josh Poimboeuf
2016-09-21  0:57   ` Andy Lutomirski
2016-09-21  2:52     ` Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 2/9] x86/entry/32: rename 'error_code' to 'common_exception' Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 3/9] x86/entry/32: fix the end of the stack for newly forked tasks Josh Poimboeuf
2016-09-21  1:10   ` Brian Gerst
2016-09-21  3:25     ` Josh Poimboeuf
2016-09-21  3:33       ` Josh Poimboeuf
2016-09-21  6:39       ` Andy Lutomirski
2016-09-21 11:35         ` Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 4/9] x86/head/32: fix the end of the stack for idle tasks Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 5/9] x86/smp: fix initial idle stack location on 32-bit Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 6/9] x86/asm/head: use a common function for starting CPUs Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 7/9] x86/head: put real return address on idle task stack Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 8/9] x86/head: fix the end of the stack for idle tasks Josh Poimboeuf
2016-09-20 20:02 ` [PATCH 9/9] x86: move _stext marker to before head code Josh Poimboeuf

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