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From: Kristen Carlson Accardi <kristen@linux.intel.com>
To: keescook@chromium.org, tglx@linutronix.de, mingo@redhat.com,
	bp@alien8.de, Josh Poimboeuf <jpoimboe@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: arjan@linux.intel.com, x86@kernel.org,
	linux-kernel@vger.kernel.org,
	kernel-hardening@lists.openwall.com, rick.p.edgecombe@intel.com,
	Kristen Carlson Accardi <kristen@linux.intel.com>
Subject: [PATCH v3 01/10] objtool: Do not assume order of parent/child functions
Date: Tue, 23 Jun 2020 10:23:18 -0700	[thread overview]
Message-ID: <20200623172327.5701-2-kristen@linux.intel.com> (raw)
In-Reply-To: <20200623172327.5701-1-kristen@linux.intel.com>

If a .cold function is examined prior to it's parent, the link
to the parent/child function can be overwritten when the parent
is examined. Only update pfunc and cfunc if they were previously
nil to prevent this from happening.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 tools/objtool/elf.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 84225679f96d..f953d3a15612 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -434,7 +434,13 @@ static int read_symbols(struct elf *elf)
 			size_t pnamelen;
 			if (sym->type != STT_FUNC)
 				continue;
-			sym->pfunc = sym->cfunc = sym;
+
+			if (sym->pfunc == NULL)
+				sym->pfunc = sym;
+
+			if (sym->cfunc == NULL)
+				sym->cfunc = sym;
+
 			coldstr = strstr(sym->name, ".cold");
 			if (!coldstr)
 				continue;
-- 
2.20.1


  reply	other threads:[~2020-06-23 17:24 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-23 17:23 [PATCH v3 00/10] Function Granular KASLR Kristen Carlson Accardi
2020-06-23 17:23 ` Kristen Carlson Accardi [this message]
2020-06-24  3:08   ` [PATCH v3 01/10] objtool: Do not assume order of parent/child functions Josh Poimboeuf
2020-06-23 17:23 ` [PATCH v3 02/10] x86: tools/relocs: Support >64K section headers Kristen Carlson Accardi
2020-06-23 17:23 ` [PATCH v3 03/10] x86/boot: Allow a "silent" kaslr random byte fetch Kristen Carlson Accardi
2020-06-23 17:23 ` [PATCH v3 04/10] x86: Makefile: Add build and config option for CONFIG_FG_KASLR Kristen Carlson Accardi
2020-06-23 17:23 ` [PATCH v3 05/10] x86: Make sure _etext includes function sections Kristen Carlson Accardi
2020-06-24  4:52   ` Kees Cook
2020-06-23 17:23 ` [PATCH v3 06/10] x86/tools: Add relative relocs for randomized functions Kristen Carlson Accardi
2020-06-23 17:23 ` [PATCH v3 07/10] x86/boot/compressed: change definition of STATIC Kristen Carlson Accardi
2020-06-24  6:54   ` Kees Cook
2020-06-23 17:23 ` [PATCH v3 08/10] x86: Add support for function granular KASLR Kristen Carlson Accardi
2020-06-24  7:11   ` Kees Cook
2020-06-23 17:23 ` [PATCH v3 09/10] kallsyms: Hide layout Kristen Carlson Accardi
2020-06-24  7:20   ` Kees Cook
2020-06-24  7:25   ` Kees Cook
2020-06-24 10:21   ` Jann Horn
2020-06-24 15:18     ` Kees Cook
2020-06-25 16:19       ` Kristen Carlson Accardi
2020-07-07 22:58       ` Kristen Carlson Accardi
2020-07-07 23:16         ` Luck, Tony
2020-07-08 16:47           ` Kristen Carlson Accardi
2020-06-23 17:23 ` [PATCH v3 10/10] module: Reorder functions Kristen Carlson Accardi
2020-06-24  7:40 ` [PATCH v3 00/10] Function Granular KASLR Kees Cook

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