From: Peter Zijlstra <peterz@infradead.org>
To: torvalds@linux-foundation.org, tglx@linutronix.de, hpa@zytor.com,
julien.thierry@arm.com, will.deacon@arm.com, luto@amacapital.net,
mingo@kernel.org, catalin.marinas@arm.com, james.morse@arm.com,
valentin.schneider@arm.com, brgerst@gmail.com,
jpoimboe@redhat.com, luto@kernel.org, bp@alien8.de,
dvlasenk@redhat.com
Cc: linux-kernel@vger.kernel.org, dvyukov@google.com, rostedt@goodmis.org
Subject: Re: [PATCH 00/20] objtool: UACCESS validation v3
Date: Thu, 7 Mar 2019 13:55:26 +0100 [thread overview]
Message-ID: <20190307125526.GB32534@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190307120317.GD32477@hirez.programming.kicks-ass.net>
On Thu, Mar 07, 2019 at 01:03:17PM +0100, Peter Zijlstra wrote:
> 01c3 20d8: 77 08 ja 20e2 <__do_sys_waitid+0x1cd>
taken:
randconfig-build/kernel/exit.o: warning: objtool: __do_sys_waitid()+0x1c3: (branch)
> ffffffffffffe0f5 alternative("", __stringify(__ASM_STAC), X86_FEATURE_SMAP);
> 01c8 20dd: 90 nop
> 01c9 20de: 90 nop
> 01ca 20df: 90 nop
Bye-bye STAC, jumped straight over.
> 01cd 20e2: 83 f0 01 xor $0x1,%eax
> 01d0 20e5: 48 89 c2 mov %rax,%rdx
> 01d3 20e8: 83 e2 01 and $0x1,%edx
> 01d6 20eb: 48 83 c2 02 add $0x2,%rdx
> 01da 20ef: 48 ff 04 d5 00 00 00 incq 0x0(,%rdx,8)
> 01e1 20f6: 00
> 01de 20f3: R_X86_64_32S _ftrace_branch+0x148
> 01e2 20f7: 84 c0 test %al,%al
> 01e4 20f9: 75 2d jne 2128 <__do_sys_waitid+0x213>
we do not take this branch and fall-through.
> ffffffffffffe0eb return -EFAULT;
> ffffffffffffe0eb
> ffffffffffffe0eb unsafe_put_user(signo, &infop->si_signo, Efault);
> 01e6 20fb: 44 89 33 mov %r14d,(%rbx)
fault, take exception:
randconfig-build/kernel/exit.o: warning: objtool: __do_sys_waitid()+0x1e6: (alt)
Relocation section '.rela__ex_table' at offset 0x21568 contains 18 entries:
Offset Info Type Sym. Value Sym. Name + Addend
000000000000 000200000002 R_X86_64_PC32 0000000000000000 .text + 20fb
000000000004 000200000002 R_X86_64_PC32 0000000000000000 .text + 2125
> ffffffffffffefe5 Efault:
> ffffffffffffe0eb user_access_end();
> 0210 2125: 90 nop
> 0211 2126: 90 nop
> 0212 2127: 90 nop
randconfig-build/kernel/exit.o: warning: objtool: __do_sys_waitid()+0x210: (alt)
000000000034 000200000002 R_X86_64_PC32 0000000000000000 .text + 2125
000000000038 00c800000002 R_X86_64_PC32 0000000000000000 .altinstr_replacement + c
0000000000000000 <.altinstr_replacement>:
c: 0f 01 ca clac
randconfig-build/kernel/exit.o: warning: objtool: .altinstr_replacement+0xc: redundant UACCESS disable
next prev parent reply other threads:[~2019-03-07 12:55 UTC|newest]
Thread overview: 100+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-07 11:45 [PATCH 00/20] objtool: UACCESS validation v3 Peter Zijlstra
2019-03-07 11:45 ` [PATCH 01/20] x86/ia32: Fix ia32_restore_sigcontext AC leak Peter Zijlstra
2019-03-07 11:45 ` [PATCH 02/20] i915,uaccess: Fix redundant CLAC Peter Zijlstra
2019-03-07 11:45 ` [PATCH 03/20] x86/uaccess: Move copy_user_handle_tail into asm Peter Zijlstra
2019-03-08 18:53 ` Josh Poimboeuf
2019-03-08 19:48 ` Peter Zijlstra
2019-03-08 19:53 ` Josh Poimboeuf
2019-03-10 13:22 ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 04/20] x86/uaccess: Fix up the fixup Peter Zijlstra
2019-03-07 11:45 ` [PATCH 05/20] x86/uaccess/xen: Suppress SMAP warnings Peter Zijlstra
2019-03-07 12:22 ` Juergen Gross
2019-03-07 12:32 ` Peter Zijlstra
2019-03-07 12:36 ` Juergen Gross
2019-03-08 19:00 ` Josh Poimboeuf
2019-03-08 19:03 ` Josh Poimboeuf
2019-03-10 13:19 ` Peter Zijlstra
2019-03-11 17:59 ` Josh Poimboeuf
2019-03-08 19:50 ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 06/20] x86/uaccess: Always inline user_access_begin() Peter Zijlstra
2019-03-07 11:45 ` [PATCH 07/20] x86/uaccess: Always inline force_valid_ss() Peter Zijlstra
2019-03-07 13:50 ` Peter Zijlstra
2019-03-07 18:05 ` Andy Lutomirski
2019-03-07 18:59 ` Peter Zijlstra
2019-03-07 19:06 ` Andy Lutomirski
2019-03-07 11:45 ` [PATCH 08/20] x86/uaccess: Introduce user_access_{save,restore}() Peter Zijlstra
2019-03-07 11:45 ` [PATCH 09/20] x86/uaccess,kasan: Fix KASAN vs SMAP Peter Zijlstra
2019-03-07 11:45 ` [PATCH 10/20] x86/uaccess,ubsan: Fix UBSAN " Peter Zijlstra
2019-03-07 11:45 ` [PATCH 11/20] x86/uaccess,ftrace: Fix ftrace_likely_update() " Peter Zijlstra
2019-03-07 11:45 ` [PATCH 12/20] objtool: Set insn->func for alternatives Peter Zijlstra
2019-03-08 19:16 ` Josh Poimboeuf
2019-03-08 19:51 ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 13/20] objtool: Hande function aliases Peter Zijlstra
2019-03-08 19:23 ` Josh Poimboeuf
2019-03-08 19:52 ` Peter Zijlstra
2019-03-08 20:00 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 14/20] objtool: Rewrite add_ignores() Peter Zijlstra
2019-03-08 19:29 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 15/20] objtool: Add --backtrace support Peter Zijlstra
2019-03-08 19:33 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 16/20] objtool: Rewrite alt->skip_orig Peter Zijlstra
2019-03-08 20:15 ` Josh Poimboeuf
2019-03-08 21:34 ` Peter Zijlstra
2019-03-08 22:27 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 17/20] objtool: Fix sibling call detection Peter Zijlstra
2019-03-08 20:22 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 18/20] objtool: Add UACCESS validation Peter Zijlstra
2019-03-07 16:33 ` Linus Torvalds
2019-03-07 17:10 ` hpa
2019-03-07 17:41 ` Peter Zijlstra
2019-03-07 17:54 ` Linus Torvalds
2019-03-07 18:48 ` Peter Zijlstra
2019-03-07 18:51 ` hpa
2019-03-07 19:03 ` Peter Zijlstra
2019-03-08 15:01 ` Josh Poimboeuf
2019-03-08 15:07 ` Peter Zijlstra
2019-03-07 20:23 ` Peter Zijlstra
2019-03-07 20:40 ` Peter Zijlstra
2019-03-08 15:07 ` Josh Poimboeuf
2019-03-08 15:23 ` Peter Zijlstra
2019-03-07 20:15 ` Andrey Ryabinin
2019-03-07 20:33 ` Peter Zijlstra
2019-03-07 20:40 ` Andrey Ryabinin
2019-03-07 20:42 ` Peter Zijlstra
2019-03-08 21:02 ` Josh Poimboeuf
2019-03-08 21:31 ` Peter Zijlstra
2019-03-08 21:54 ` Josh Poimboeuf
2019-03-10 13:10 ` Peter Zijlstra
2019-03-11 18:01 ` Josh Poimboeuf
2019-03-07 11:45 ` [PATCH 19/20] objtool: uaccess PUSHF/POPF support Peter Zijlstra
2019-03-08 21:11 ` Josh Poimboeuf
2019-03-10 13:12 ` Peter Zijlstra
2019-03-07 11:45 ` [PATCH 20/20] objtool: Add Direction Flag validation Peter Zijlstra
2019-03-08 21:16 ` Josh Poimboeuf
2019-03-08 21:33 ` Peter Zijlstra
2019-03-08 21:56 ` Josh Poimboeuf
2019-03-10 13:13 ` Peter Zijlstra
2019-03-11 18:00 ` Josh Poimboeuf
2019-03-07 12:03 ` [PATCH 00/20] objtool: UACCESS validation v3 Peter Zijlstra
2019-03-07 12:55 ` Peter Zijlstra [this message]
2019-03-07 13:13 ` Peter Zijlstra
2019-03-07 16:47 ` Josh Poimboeuf
2019-03-07 16:50 ` Josh Poimboeuf
2019-03-07 17:00 ` Linus Torvalds
2019-03-07 17:17 ` Josh Poimboeuf
2019-03-07 17:38 ` Peter Zijlstra
2019-03-07 17:45 ` Linus Torvalds
2019-03-07 18:18 ` Steven Rostedt
2019-03-10 13:16 ` Peter Zijlstra
2019-04-19 10:08 ` [PATCH] compiler.h, tracing: Remove CONFIG_PROFILE_ALL_BRANCHES Ingo Molnar
2019-04-19 13:04 ` Steven Rostedt
2019-03-07 17:04 ` [PATCH 00/20] objtool: UACCESS validation v3 hpa
2019-03-07 17:18 ` Josh Poimboeuf
2019-03-07 17:29 ` hpa
2019-03-07 17:45 ` Josh Poimboeuf
2019-03-07 17:48 ` Linus Torvalds
2019-03-07 17:43 ` Peter Zijlstra
2019-03-07 17:48 ` Josh Poimboeuf
2019-04-03 8:21 ` [tip:core/objtool] tracing: Improve "if" macro code generation tip-bot for Josh Poimboeuf
2019-03-07 16:31 ` [PATCH 00/20] objtool: UACCESS validation v3 Linus Torvalds
2019-03-07 17:14 ` hpa
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