From: Borislav Petkov <bp@alien8.de>
To: Jiri Slaby <jslaby@suse.cz>
Cc: mingo@redhat.com, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org
Subject: Re: [PATCH v7 05/28] x86/asm/entry: annotate THUNKs
Date: Thu, 14 Feb 2019 11:34:57 +0100 [thread overview]
Message-ID: <20190214103457.GA12467@zn.tnic> (raw)
In-Reply-To: <cd09f00f-7174-4d06-50a2-3cc056b7d763@suse.cz>
On Thu, Feb 14, 2019 at 11:03:14AM +0100, Jiri Slaby wrote:
> first results in objtool complaints:
> > arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0x190: unsupported intra-function call
> > arch/x86/entry/entry_64.o: warning: objtool: If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE.
objtool can be fixed.
> and also the crash is misleading:
> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> > #PF error: [WRITE]
> > PGD 0 P4D 0
> > Oops: 0002 [#1] PREEMPT SMP
> ...
> > RIP: 0010:__switch_to_asm+0x70/0x80
You have RIP.
But yes, there is some disadvantage of not having global symbols vs
polluting the ELF symtable with random ones.
If we're going to keep them global, then we should at least make sure
their names have proper prefix so that at least one can map them to the
kernel namespace they belong to and there is no confusion when staring
at stack traces.
Also, they should not be a lot because the places where we do all these
funky trampoline etc games where a chunk of code is outside of the
boundaries of a function, are only a couple.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
next prev parent reply other threads:[~2019-02-14 10:35 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-30 12:46 [PATCH v7 00/28] New macros for assembler symbols Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 01/28] linkage: new " Jiri Slaby
2019-01-31 16:00 ` Borislav Petkov
2019-02-01 13:53 ` Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 02/28] x86/asm/suspend: drop ENTRY from local data Jiri Slaby
2019-01-30 15:12 ` [tip:x86/cleanups] x86/asm/suspend: Drop " tip-bot for Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 03/28] x86/asm/suspend: use SYM_DATA for data Jiri Slaby
2019-02-04 20:18 ` Borislav Petkov
2019-02-05 7:34 ` Jiri Slaby
2019-02-05 8:07 ` Borislav Petkov
2019-01-30 12:46 ` [PATCH v7 04/28] x86/asm: annotate relocate_kernel Jiri Slaby
2019-02-08 19:53 ` Borislav Petkov
2019-01-30 12:46 ` [PATCH v7 05/28] x86/asm/entry: annotate THUNKs Jiri Slaby
2019-02-09 11:25 ` Borislav Petkov
2019-02-12 10:27 ` Jiri Slaby
2019-02-12 11:05 ` Borislav Petkov
2019-02-12 11:38 ` Jiri Slaby
2019-02-12 11:46 ` Borislav Petkov
2019-02-12 11:51 ` Jiri Slaby
2019-02-12 12:13 ` Borislav Petkov
2019-02-14 10:03 ` Jiri Slaby
2019-02-14 10:34 ` Borislav Petkov [this message]
2019-01-30 12:46 ` [PATCH v7 06/28] x86/asm: annotate local pseudo-functions Jiri Slaby
2019-02-09 12:24 ` Borislav Petkov
2019-01-30 12:46 ` [PATCH v7 07/28] x86/asm/crypto: annotate local functions Jiri Slaby
2019-02-25 10:13 ` Borislav Petkov
2019-01-30 12:46 ` [PATCH v7 08/28] x86/boot/compressed: " Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 09/28] x86/asm: annotate aliases Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 10/28] x86/asm/entry: annotate interrupt symbols properly Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 11/28] x86/asm/head: annotate data appropriatelly Jiri Slaby
2019-02-25 14:53 ` Borislav Petkov
2019-01-30 12:46 ` [PATCH v7 12/28] x86/boot/compressed: " Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 13/28] um: " Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 14/28] xen/pvh: " Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 15/28] x86/asm/purgatory: start using annotations Jiri Slaby
2019-01-30 12:46 ` [PATCH v7 16/28] x86/asm: do not annotate functions by GLOBAL Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 17/28] x86/asm: use SYM_INNER_LABEL instead of GLOBAL Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 18/28] x86/asm/realmode: use SYM_DATA_* " Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 19/28] x86/asm: kill the last GLOBAL user and remove the macro Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 20/28] x86/asm: make some functions local Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 21/28] x86/asm/ftrace: mark function_hook as function Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 22/28] x86_64/asm: add ENDs to some functions and relabel with SYM_CODE_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 23/28] x86_64/asm: change all ENTRY+END to SYM_CODE_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 24/28] x86_64/asm: change all ENTRY+ENDPROC to SYM_FUNC_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 25/28] x86_32/asm: add ENDs to some functions and relabel with SYM_CODE_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 26/28] x86_32/asm: change all ENTRY+END to SYM_CODE_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 27/28] x86_32/asm: change all ENTRY+ENDPROC to SYM_FUNC_* Jiri Slaby
2019-01-30 12:47 ` [PATCH v7 28/28] x86/asm: replace WEAK uses by SYM_INNER_LABEL_ALIGN Jiri Slaby
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