From: Borislav Petkov <bp@alien8.de>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Michal Marek <mmarek@suse.cz>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>, Pedro Alves <palves@redhat.com>,
x86@kernel.org, live-patching@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 04/21] x86/hweight: Add stack frame dependency for __arch_hweight*()
Date: Sat, 18 Jul 2015 07:05:36 +0200 [thread overview]
Message-ID: <20150718050536.GA23478@nazgul.tnic> (raw)
In-Reply-To: <20150717173220.GA12761@treble.redhat.com>
On Fri, Jul 17, 2015 at 12:32:20PM -0500, Josh Poimboeuf wrote:
> Well, but this isn't some whitelist code to make stackvalidate happy.
>
> It's actually a real runtime frame pointer bug, and the rsp dependency
> is real. If it does the call without first creating the stack frame
> then it breaks frame pointer based stack traces.
I think we can live with the stack trace being a little wrong in those
__sw_* variants. And besides, we're talking about the very very small
percentage of machines (which keeps getting smaller) which don't
support POPCNT. And from those, only for the cases where the arg is not
__builtin_constant_p() because there we do the __const_hweight* thing.
I'd prefer to not clutter the code more in that case.
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
--
next prev parent reply other threads:[~2015-07-18 5:05 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-14 17:14 [PATCH v7 0/4] Compile-time stack validation Josh Poimboeuf
2015-07-14 17:14 ` [PATCH v7 1/4] x86/asm: Frame pointer macro cleanup Josh Poimboeuf
2015-07-14 17:14 ` [PATCH v7 2/4] x86/stackvalidate: Compile-time stack validation Josh Poimboeuf
2015-07-14 20:57 ` Peter Zijlstra
2015-07-14 21:11 ` Josh Poimboeuf
2015-07-14 21:08 ` Peter Zijlstra
2015-07-14 21:30 ` Josh Poimboeuf
2015-07-14 21:56 ` Peter Zijlstra
2015-07-14 22:32 ` Josh Poimboeuf
2015-07-20 16:53 ` Namhyung Kim
2015-07-20 17:50 ` Josh Poimboeuf
2015-07-21 8:02 ` Ingo Molnar
2015-07-21 12:04 ` Josh Poimboeuf
2015-07-21 8:42 ` Bernd Petrovitsch
2015-07-21 12:06 ` Josh Poimboeuf
2015-07-14 17:14 ` [PATCH v7 3/4] x86/stackvalidate: Add file and directory ignores Josh Poimboeuf
2015-07-14 17:14 ` [PATCH v7 4/4] x86/stackvalidate: Add ignore macros Josh Poimboeuf
2015-07-14 17:25 ` [PATCH v7 0/4] Compile-time stack validation Josh Poimboeuf
2015-07-15 10:16 ` Ingo Molnar
2015-07-15 16:05 ` Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 00/21] x86: Proposed fixes for stackvalidate warnings Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 01/21] stackvalidate: Process ignores earlier and add more ignore checks Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 02/21] stackvalidate: Add C version of STACKVALIDATE_IGNORE_INSN Josh Poimboeuf
2015-07-18 14:56 ` Borislav Petkov
2015-07-18 16:00 ` Josh Poimboeuf
[not found] ` <CA+55aFyoO75n-mQBrB_YBLx9yNpAjisFAqkO8+YsphD-xmgY+w@mail.gmail.com>
2015-07-18 16:40 ` Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 03/21] x86/asm: Add C versions of FRAME and ENDFRAME macros Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 04/21] x86/hweight: Add stack frame dependency for __arch_hweight*() Josh Poimboeuf
2015-07-17 17:17 ` Borislav Petkov
2015-07-17 17:32 ` Josh Poimboeuf
2015-07-18 5:05 ` Borislav Petkov [this message]
2015-07-18 13:44 ` Josh Poimboeuf
2015-07-18 14:56 ` Borislav Petkov
2015-07-18 15:57 ` Josh Poimboeuf
2015-07-19 4:12 ` Borislav Petkov
2015-07-22 0:13 ` Andy Lutomirski
2015-07-22 4:25 ` Borislav Petkov
2015-07-22 4:39 ` Andy Lutomirski
2015-07-22 4:45 ` Borislav Petkov
2015-07-17 16:47 ` [RFC PATCH 05/21] x86/xen: Add stack frame dependency to hypercall inline asm calls Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 06/21] x86/paravirt: Add stack frame dependency to PVOP " Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 07/21] x86/paravirt: Fix frame pointer usage in PV_CALLEE_SAVE_REGS_THUNK Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 08/21] x86/paravirt: Align paravirt thunk functions at 16-byte boundaries Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 09/21] x86/amd: Set ELF function type for vide() Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 10/21] x86/reboot: Add ljmp instructions to stackvalidate whitelist Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 11/21] x86/xen: Add xen_cpuid() and xen_setup_gdt() to stackvalidate whitelists Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 12/21] sched: Add __schedule() to stackvalidate whitelist Josh Poimboeuf
2015-07-17 19:46 ` Peter Zijlstra
2015-07-17 19:58 ` Andy Lutomirski
2015-07-17 21:03 ` Peter Zijlstra
2015-07-17 21:23 ` Josh Poimboeuf
2015-07-18 3:44 ` Ingo Molnar
2015-07-17 16:47 ` [RFC PATCH 13/21] x86/asm/crypto: Fix frame pointer usage in aesni-intel_asm.S Josh Poimboeuf
2015-07-17 19:43 ` Ingo Molnar
2015-07-17 19:44 ` Andy Lutomirski
2015-07-17 20:37 ` Josh Poimboeuf
2015-07-17 20:39 ` Andy Lutomirski
2015-07-17 20:44 ` Josh Poimboeuf
2015-07-17 20:46 ` Andy Lutomirski
2015-07-17 20:59 ` Josh Poimboeuf
2015-07-17 21:01 ` Andy Lutomirski
2015-07-17 21:10 ` Josh Poimboeuf
2015-07-18 8:42 ` Borislav Petkov
2015-07-18 13:46 ` Josh Poimboeuf
2015-07-18 14:25 ` Borislav Petkov
2015-07-18 15:40 ` Josh Poimboeuf
2015-07-18 2:51 ` Ingo Molnar
2015-07-18 3:56 ` Josh Poimboeuf
2015-07-20 7:56 ` Ingo Molnar
2015-07-20 13:59 ` Josh Poimboeuf
2015-07-20 17:21 ` Ingo Molnar
2015-07-20 18:00 ` Josh Poimboeuf
2015-07-22 11:52 ` Josh Poimboeuf
2015-07-20 15:30 ` Andy Lutomirski
2015-07-20 16:36 ` Josh Poimboeuf
2015-07-20 16:52 ` Peter Zijlstra
2015-07-20 17:19 ` Josh Poimboeuf
2015-07-21 8:00 ` Ingo Molnar
2015-07-21 12:06 ` Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 14/21] x86/asm/crypto: Move .Lbswap_mask data to .rodata section Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 15/21] x86/asm/crypto: Move jump_table " Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 16/21] x86/asm/crypto: Fix frame pointer usage in clmul_ghash_mul/update() Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 17/21] x86/asm/entry: Fix frame pointer usage in thunk functions Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 18/21] x86/asm/acpi: Fix frame pointer usage in do_suspend_lowlevel() Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 19/21] x86/asm: Fix frame pointer usage in rwsem functions Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 20/21] x86/asm/efi: Fix frame pointer usage in efi_call() Josh Poimboeuf
2015-07-17 16:47 ` [RFC PATCH 21/21] x86/asm/power: Fix frame pointer usage in hibernate_asm_64.S Josh Poimboeuf
2015-07-17 18:56 ` [RFC PATCH 00/21] x86: Proposed fixes for stackvalidate warnings Andy Lutomirski
2015-07-18 3:05 ` Ingo Molnar
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