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From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Arnd Bergmann <arnd@arndb.de>, Jann Horn <jannh@google.com>,
	Randy Dunlap <rdunlap@infradead.org>
Subject: Re: [PATCH 00/22] x86, objtool: several fixes/improvements
Date: Mon, 15 Jul 2019 11:52:09 +0200	[thread overview]
Message-ID: <20190715095209.GA3419@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <cover.1563150885.git.jpoimboe@redhat.com>

On Sun, Jul 14, 2019 at 07:36:55PM -0500, Josh Poimboeuf wrote:
> There have been a lot of objtool bug reports lately, mainly related to
> Clang and BPF.  As part of fixing those bugs, I added some improvements
> to objtool which uncovered yet more bugs (some kernel, some objtool).
> 
> I've given these patches a lot of testing with both GCC and Clang.  More
> compile testing of objtool would be appreciated, as the kbuild test
> robot doesn't seem to be paying much attention to my branches lately.
> 
> There are still at least three outstanding issues:
> 
> 1) With clang I see:
> 
>      drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x88: redundant UACCESS disable
> 
>    I haven't dug into it yet.
> 
> 2) There's also an issue in clang where a large switch table had a bunch
>    of unused (bad) entries.  It's not a code correctness issue, but
>    hopefully it can get fixed in clang anyway.  See patch 20/22 for more
>    details.
> 
> 3) CONFIG_LIVEPATCH is causing some objtool "unreachable instruction"
>    warnings due to the new -flive-patching flag.  I have some fixes
>    pending, but this patch set is already long enough.
> 
> 
> Jann Horn (1):
>   objtool: Support repeated uses of the same C jump table
> 
> Josh Poimboeuf (21):
>   x86/paravirt: Fix callee-saved function ELF sizes
>   x86/kvm: Fix fastop function ELF metadata
>   x86/kvm: Fix frame pointer usage in vmx_vmenter()
>   x86/kvm: Don't call kvm_spurious_fault() from .fixup
>   x86/entry: Fix thunk function ELF sizes
>   x86/head/64: Annotate start_cpu0() as non-callable
>   x86/uaccess: Remove ELF function annotation from
>     copy_user_handle_tail()
>   x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail()
>   x86/uaccess: Remove redundant CLACs in getuser/putuser error paths
>   bpf: Disable GCC -fgcse optimization for ___bpf_prog_run()
>   objtool: Add mcsafe_handle_tail() to the uaccess safe list
>   objtool: Track original function across branches
>   objtool: Refactor function alias logic
>   objtool: Warn on zero-length functions
>   objtool: Change dead_end_function() to return boolean
>   objtool: Do frame pointer check before dead end check
>   objtool: Refactor sibling call detection logic
>   objtool: Refactor jump table code
>   objtool: Fix seg fault on bad switch table entry
>   objtool: convert insn type to enum
>   objtool: Support conditional retpolines

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>

  parent reply	other threads:[~2019-07-15  9:52 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-15  0:36 [PATCH 00/22] x86, objtool: several fixes/improvements Josh Poimboeuf
2019-07-15  0:36 ` [PATCH 01/22] x86/paravirt: Fix callee-saved function ELF sizes Josh Poimboeuf
2019-07-15  4:58   ` Juergen Gross
2019-07-15 12:43     ` Josh Poimboeuf
2019-07-15  0:36 ` [PATCH 02/22] x86/kvm: Fix fastop function ELF metadata Josh Poimboeuf
2019-07-15  9:05   ` Paolo Bonzini
2019-07-15  0:36 ` [PATCH 03/22] x86/kvm: Fix frame pointer usage in vmx_vmenter() Josh Poimboeuf
2019-07-15  9:04   ` Paolo Bonzini
2019-07-15 12:37     ` Josh Poimboeuf
2019-07-15 13:03       ` Paolo Bonzini
2019-07-15 13:35         ` Josh Poimboeuf
2019-07-15 18:17           ` Paolo Bonzini
2019-07-15  0:36 ` [PATCH 04/22] x86/kvm: Don't call kvm_spurious_fault() from .fixup Josh Poimboeuf
2019-07-15  9:07   ` Paolo Bonzini
2019-07-15 12:40     ` Josh Poimboeuf
2019-07-15 13:05       ` Paolo Bonzini
2019-07-15 13:25         ` Josh Poimboeuf
2019-07-15 18:16           ` Paolo Bonzini
2019-07-15  0:37 ` [PATCH 05/22] x86/entry: Fix thunk function ELF sizes Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 06/22] x86/head/64: Annotate start_cpu0() as non-callable Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 07/22] x86/uaccess: Remove ELF function annotation from copy_user_handle_tail() Josh Poimboeuf
2019-07-16 18:16   ` Nick Desaulniers
2019-07-16 18:51     ` Peter Zijlstra
2019-07-15  0:37 ` [PATCH 08/22] x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail() Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 09/22] x86/uaccess: Remove redundant CLACs in getuser/putuser error paths Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 10/22] bpf: Disable GCC -fgcse optimization for ___bpf_prog_run() Josh Poimboeuf
2019-07-16 18:15   ` Nick Desaulniers
2019-07-16 23:02     ` Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 11/22] objtool: Add mcsafe_handle_tail() to the uaccess safe list Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 12/22] objtool: Track original function across branches Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 13/22] objtool: Refactor function alias logic Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 14/22] objtool: Warn on zero-length functions Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 15/22] objtool: Change dead_end_function() to return boolean Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 16/22] objtool: Do frame pointer check before dead end check Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 17/22] objtool: Refactor sibling call detection logic Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 18/22] objtool: Refactor jump table code Josh Poimboeuf
2019-07-15  9:38   ` Peter Zijlstra
2019-07-15  0:37 ` [PATCH 19/22] objtool: Support repeated uses of the same C jump table Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 20/22] objtool: Fix seg fault on bad switch table entry Josh Poimboeuf
2019-07-15 17:24   ` Nick Desaulniers
2019-07-15 17:29     ` Josh Poimboeuf
2019-07-18 23:02       ` Nick Desaulniers
2019-07-15  0:37 ` [PATCH 21/22] objtool: convert insn type to enum Josh Poimboeuf
2019-07-15  0:37 ` [PATCH 22/22] objtool: Support conditional retpolines Josh Poimboeuf
2019-07-15  9:52 ` Peter Zijlstra [this message]
2019-07-15 19:38 ` [PATCH 00/22] x86, objtool: several fixes/improvements Josh Poimboeuf
2019-07-15 21:45   ` Nick Desaulniers
2019-07-16 23:17     ` Josh Poimboeuf
2019-07-18 22:26       ` Nick Desaulniers
2019-09-27 20:24         ` Nick Desaulniers

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