All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josh Poimboeuf <jpoimboe@kernel.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Miroslav Benes <mbenes@suse.cz>,
	Nick Desaulniers <ndesaulniers@google.com>
Subject: [PATCH v3 8/8] objtool: Move noreturn function list to separate file
Date: Tue, 18 Apr 2023 14:27:54 -0700	[thread overview]
Message-ID: <cecacf07a69a244c74474c18b7652627de67a528.1681853186.git.jpoimboe@kernel.org> (raw)
In-Reply-To: <cover.1681853186.git.jpoimboe@kernel.org>

This makes it a little cleaner and easier to maintain.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/Documentation/objtool.txt |  5 ++-
 tools/objtool/check.c                   | 44 ++----------------------
 tools/objtool/noreturns.h               | 45 +++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 44 deletions(-)
 create mode 100644 tools/objtool/noreturns.h

diff --git a/tools/objtool/Documentation/objtool.txt b/tools/objtool/Documentation/objtool.txt
index 2cd1fa16ed08..00f0a7e385ec 100644
--- a/tools/objtool/Documentation/objtool.txt
+++ b/tools/objtool/Documentation/objtool.txt
@@ -306,9 +306,8 @@ the objtool maintainers.
 3. file.o: warning: objtool: foo+0x48c: bar() is missing a __noreturn annotation
 
    The call from foo() to bar() doesn't return, but bar() is missing the
-   __noreturn annotation.  NOTE: In addition to adding the __noreturn
-   annotation, the function name also needs to be added to
-   'global_noreturns' in tools/objtool/check.c.
+   __noreturn annotation.  NOTE: In addition to annotating the function
+   with __noreturn, please also add it to tools/objtool/noreturns.h.
 
 4. file.o: warning: objtool: func(): can't find starting instruction
    or
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 2047a6d5339b..69794c25f857 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -192,49 +192,11 @@ static bool __dead_end_function(struct objtool_file *file, struct symbol *func,
 	struct instruction *insn;
 	bool empty = true;
 
-	/*
-	 * Unfortunately these have to be hard coded because the noreturn
-	 * attribute isn't provided in ELF data. Keep 'em sorted.
-	 */
+#define NORETURN(func) __stringify(func),
 	static const char * const global_noreturns[] = {
-		"__invalid_creds",
-		"__module_put_and_kthread_exit",
-		"__reiserfs_panic",
-		"__stack_chk_fail",
-		"__ubsan_handle_builtin_unreachable",
-		"arch_call_rest_init",
-		"arch_cpu_idle_dead",
-		"btrfs_assertfail",
-		"cpu_bringup_and_idle",
-		"cpu_startup_entry",
-		"do_exit",
-		"do_group_exit",
-		"do_task_dead",
-		"ex_handler_msr_mce",
-		"fortify_panic",
-		"hlt_play_dead",
-		"hv_ghcb_terminate",
-		"kthread_complete_and_exit",
-		"kthread_exit",
-		"kunit_try_catch_throw",
-		"machine_real_restart",
-		"make_task_dead",
-		"mpt_halt_firmware",
-		"nmi_panic_self_stop",
-		"panic",
-		"panic_smp_self_stop",
-		"rest_init",
-		"rewind_stack_and_make_dead",
-		"sev_es_terminate",
-		"snp_abort",
-		"start_kernel",
-		"stop_this_cpu",
-		"usercopy_abort",
-		"x86_64_start_kernel",
-		"x86_64_start_reservations",
-		"xen_cpu_bringup_again",
-		"xen_start_kernel",
+#include "noreturns.h"
 	};
+#undef NORETURN
 
 	if (!func)
 		return false;
diff --git a/tools/objtool/noreturns.h b/tools/objtool/noreturns.h
new file mode 100644
index 000000000000..cede6068ddf6
--- /dev/null
+++ b/tools/objtool/noreturns.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * This is a (sorted!) list of all known __noreturn functions in the kernel.
+ * It's needed for objtool to properly reverse-engineer the control flow graph.
+ *
+ * Yes, this is unfortunate.  A better solution is in the works.
+ */
+NORETURN(__invalid_creds)
+NORETURN(__module_put_and_kthread_exit)
+NORETURN(__reiserfs_panic)
+NORETURN(__stack_chk_fail)
+NORETURN(__ubsan_handle_builtin_unreachable)
+NORETURN(arch_call_rest_init)
+NORETURN(arch_cpu_idle_dead)
+NORETURN(btrfs_assertfail)
+NORETURN(cpu_bringup_and_idle)
+NORETURN(cpu_startup_entry)
+NORETURN(do_exit)
+NORETURN(do_group_exit)
+NORETURN(do_task_dead)
+NORETURN(ex_handler_msr_mce)
+NORETURN(fortify_panic)
+NORETURN(hlt_play_dead)
+NORETURN(hv_ghcb_terminate)
+NORETURN(kthread_complete_and_exit)
+NORETURN(kthread_exit)
+NORETURN(kunit_try_catch_throw)
+NORETURN(machine_real_restart)
+NORETURN(make_task_dead)
+NORETURN(mpt_halt_firmware)
+NORETURN(nmi_panic_self_stop)
+NORETURN(panic)
+NORETURN(panic_smp_self_stop)
+NORETURN(rest_init)
+NORETURN(rewind_stack_and_make_dead)
+NORETURN(sev_es_terminate)
+NORETURN(snp_abort)
+NORETURN(start_kernel)
+NORETURN(stop_this_cpu)
+NORETURN(usercopy_abort)
+NORETURN(x86_64_start_kernel)
+NORETURN(x86_64_start_reservations)
+NORETURN(xen_cpu_bringup_again)
+NORETURN(xen_start_kernel)
-- 
2.39.2


  parent reply	other threads:[~2023-04-18 21:28 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-18 21:27 [PATCH v3 0/8] objtool: warning improvements Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 1/8] objtool: Limit unreachable warnings to once per function Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 2/8] objtool: Add verbose option for disassembling affected functions Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 3/8] objtool: Include backtrace in verbose mode Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 4/8] objtool: Detect missing __noreturn annotations Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 5/8] objtool: Ignore exc_double_fault() __noreturn warnings Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 6/8] objtool: Remove superfluous global_noreturns entries Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` [PATCH v3 7/8] tools/lib/subcmd: Replace NORETURN usage with __noreturn Josh Poimboeuf
2023-05-18 11:08   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2023-04-18 21:27 ` Josh Poimboeuf [this message]
2023-05-18 11:08   ` [tip: objtool/core] objtool: Move noreturn function list to separate file tip-bot2 for Josh Poimboeuf
2023-04-19 14:51 ` [PATCH v3 0/8] objtool: warning improvements Miroslav Benes

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=cecacf07a69a244c74474c18b7652627de67a528.1681853186.git.jpoimboe@kernel.org \
    --to=jpoimboe@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mbenes@suse.cz \
    --cc=ndesaulniers@google.com \
    --cc=peterz@infradead.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.