From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
live-patching@vger.kernel.org,
Joe Lawrence <joe.lawrence@redhat.com>,
Song Liu <song@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
Petr Mladek <pmladek@suse.com>
Subject: Re: [PATCH 47/48] objtool: Improve and simplify prefix symbol detection
Date: Thu, 23 Apr 2026 17:21:39 +0200 [thread overview]
Message-ID: <20260423152139.GH1064669@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <be5iv2gj7mfmizs6v3dsygnv2c2tn7aniabz3fopgrbnnnfdnj@433avj4qybyp>
On Thu, Apr 23, 2026 at 08:19:57AM -0700, Josh Poimboeuf wrote:
> On Thu, Apr 23, 2026 at 10:55:20AM +0200, Peter Zijlstra wrote:
> > On Wed, Apr 22, 2026 at 09:04:15PM -0700, Josh Poimboeuf wrote:
> > > Only create prefix symbols for functions that have
> > > __patchable_function_entries entries, since those are the only functions
> > > where prefix NOPs are intentional.
> >
> > __CFI_TYPE() as used in SYM_TYPED_ENTRY() will also generate the NOPs
> > but will not have __patchable_function_entries, because ASM not
> > compiler.
>
> Hm, but those already have __cfi_ symbols, no?
Yes, but you said those were 'short' -- but fair, I did not check if the
asm stub generated symbols of the correct length.
next prev parent reply other threads:[~2026-04-23 15:21 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-23 4:03 [PATCH 00/48] objtool/klp: Some klp-build fixes and improvements Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 01/48] objtool/klp: Fix is_uncorrelated_static_local() for Clang Josh Poimboeuf
2026-04-23 18:45 ` Song Liu
2026-04-23 4:03 ` [PATCH 02/48] objtool/klp: Fix .data..once static local non-correlation Josh Poimboeuf
2026-04-23 18:54 ` Song Liu
2026-04-23 23:34 ` Josh Poimboeuf
2026-04-23 23:54 ` Song Liu
2026-04-23 4:03 ` [PATCH 03/48] objtool/klp: Don't correlate __ADDRESSABLE() symbols Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 04/48] objtool/klp: Ignore __UNIQUE_ID_*() PCI stub functions Josh Poimboeuf
2026-04-23 19:05 ` Song Liu
2026-04-23 19:31 ` Josh Poimboeuf
2026-04-23 21:33 ` Song Liu
2026-04-23 23:50 ` Josh Poimboeuf
2026-04-23 23:54 ` Song Liu
2026-04-23 4:03 ` [PATCH 05/48] objtool: Move mark_rodata() to elf.c Josh Poimboeuf
2026-04-23 8:19 ` Peter Zijlstra
2026-04-23 4:03 ` [PATCH 06/48] objtool/klp: Don't correlate rodata symbols Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 07/48] objtool/klp: Don't correlate absolute symbols Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 08/48] objtool/klp: Don't correlate __initstub__ symbols Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 09/48] objtool/klp: Fix create_fake_symbols() skipping entsize-based sections Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 10/48] objtool/klp: Fix --debug-checksum for duplicate symbol names Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 11/48] objtool/klp: Fix handling of zero-length .altinstr_replacement sections Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 12/48] objtool/klp: Fix cloning of zero-length section symbols Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 13/48] objtool/klp: Fix XXH3 state memory leak Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 14/48] objtool/klp: Fix extraction of text annotations for alternatives Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 15/48] objtool/klp: Fix kCFI trap handling Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 16/48] objtool/klp: Fix relocation conversion failures for R_X86_64_NONE Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 17/48] objtool: Fix reloc hash collision in find_reloc_by_dest_range() Josh Poimboeuf
2026-04-23 8:32 ` Peter Zijlstra
2026-04-23 16:34 ` Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 18/48] klp-build: Fix hang on out-of-date .config Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 19/48] klp-build: Fix checksum comparison for changed offsets Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 20/48] klp-build: Don't use errexit Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 21/48] klp-build: Validate patch file existence Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 22/48] klp-build: Suppress excessive fuzz output by default Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 23/48] klp-build: Fix patch cleanup on interrupt Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 24/48] klp-build: Reject patches to vDSO Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 25/48] klp-build: Reject patches to realmode Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 26/48] objtool/klp: Don't set sym->file for section symbols Josh Poimboeuf
2026-04-23 8:34 ` Peter Zijlstra
2026-04-23 4:03 ` [PATCH 27/48] objtool: Include libsubcmd headers directly from source tree Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 28/48] objtool/klp: Create empty checksum sections for function-less object files Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 29/48] klp-build: Print "objtool klp diff" command in verbose mode Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 30/48] objtool/klp: Handle Clang .data..Lanon anonymous data sections Josh Poimboeuf
2026-04-23 4:03 ` [PATCH 31/48] objtool: Add is_alias_sym() helper Josh Poimboeuf
2026-04-23 8:35 ` Peter Zijlstra
2026-04-23 4:04 ` [PATCH 32/48] objtool: Add is_cold_func() helper Josh Poimboeuf
2026-04-23 8:38 ` Peter Zijlstra
2026-04-23 15:12 ` Josh Poimboeuf
2026-04-23 15:14 ` Peter Zijlstra
2026-04-23 19:23 ` Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 33/48] objtool/klp: Extricate checksum calculation from validate_branch() Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 34/48] objtool: Consolidate file decoding into decode_file() Josh Poimboeuf
2026-04-23 8:41 ` Peter Zijlstra
2026-04-23 4:04 ` [PATCH 35/48] objtool/klp: Add "objtool klp checksum" subcommand Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 36/48] klp-build: Use " Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 37/48] objtool/klp: Remove "objtool --checksum" Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 38/48] klp-build: Validate short-circuit prerequisites Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 39/48] objtool: Replace iterator callbacks with for_each_sym_by_*() Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 40/48] objtool/klp: Calculate object checksums Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 41/48] objtool/klp: Rewrite symbol correlation algorithm Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 42/48] objtool/klp: Add correlation debugging output Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 43/48] objtool: Add insn_sym() helper Josh Poimboeuf
2026-04-23 8:45 ` Peter Zijlstra
2026-04-23 15:14 ` Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 44/48] objtool/klp: Fix position-dependent checksums for non-relocated jumps/calls Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 45/48] x86/Kconfig: Enable CONFIG_PREFIX_SYMBOLS for FineIBT Josh Poimboeuf
2026-04-23 8:47 ` Peter Zijlstra
2026-04-23 15:16 ` Josh Poimboeuf
2026-04-23 15:19 ` Peter Zijlstra
2026-04-23 16:23 ` Josh Poimboeuf
2026-04-23 16:29 ` Peter Zijlstra
2026-04-23 23:30 ` Josh Poimboeuf
2026-04-24 3:38 ` Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 46/48] objtool/klp: Make function prefix handling more generic Josh Poimboeuf
2026-04-23 4:04 ` [PATCH 47/48] objtool: Improve and simplify prefix symbol detection Josh Poimboeuf
2026-04-23 8:55 ` Peter Zijlstra
2026-04-23 15:19 ` Josh Poimboeuf
2026-04-23 15:21 ` Peter Zijlstra [this message]
2026-04-23 4:04 ` [PATCH 48/48] objtool/klp: Cache dont_correlate() result Josh Poimboeuf
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