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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 v2 1/9] objtool: Do not assume order of parent/child functions
Date: Thu, 21 May 2020 09:56:32 -0700	[thread overview]
Message-ID: <20200521165641.15940-2-kristen@linux.intel.com> (raw)
In-Reply-To: <20200521165641.15940-1-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 c4857fa3f1d1..b998c853a1f0 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -408,7 +408,13 @@ 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:[~2020-05-21 16:57 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21 16:56 [PATCH v2 0/9] Function Granular KASLR Kristen Carlson Accardi
2020-05-21 16:56 ` Kristen Carlson Accardi [this message]
2020-05-21 16:56 ` [PATCH v2 2/9] x86: tools/relocs: Support >64K section headers Kristen Carlson Accardi
2020-05-21 16:56 ` [PATCH v2 3/9] x86/boot: Allow a "silent" kaslr random byte fetch Kristen Carlson Accardi
2020-05-21 16:56 ` [PATCH v2 4/9] x86: Makefile: Add build and config option for CONFIG_FG_KASLR Kristen Carlson Accardi
2020-05-21 20:00   ` Kees Cook
2020-05-21 16:56 ` [PATCH v2 5/9] x86: Make sure _etext includes function sections Kristen Carlson Accardi
2020-05-21 18:11   ` Kees Cook
2020-05-21 16:56 ` [PATCH v2 6/9] x86/tools: Add relative relocs for randomized functions Kristen Carlson Accardi
2020-05-21 19:54   ` Kees Cook
2020-05-21 16:56 ` [PATCH v2 7/9] x86: Add support for function granular KASLR Kristen Carlson Accardi
2020-05-21 21:08   ` Kees Cook
2020-05-21 21:42     ` Kristen Carlson Accardi
2020-05-21 21:42       ` Kristen Carlson Accardi
2020-06-04 17:27     ` Kristen Carlson Accardi
2020-06-04 17:27       ` Kristen Carlson Accardi
2020-06-04 22:37       ` Kees Cook
2020-05-21 16:56 ` [PATCH v2 8/9] kallsyms: Hide layout Kristen Carlson Accardi
2020-05-21 21:14   ` Kees Cook
2020-05-21 16:56 ` [PATCH v2 9/9] module: Reorder functions Kristen Carlson Accardi
2020-05-21 21:33   ` Kees Cook
2020-06-09 20:14     ` Kristen Carlson Accardi
2020-06-09 20:14       ` Kristen Carlson Accardi
2020-06-09 20:42       ` Kees Cook
2020-06-09 20:59         ` Kristen Carlson Accardi
2020-06-09 20:59           ` Kristen Carlson Accardi
2020-05-21 21:54 ` [PATCH v2 0/9] Function Granular KASLR Kees Cook
2020-05-21 22:26 ` Thomas Gleixner
2020-05-21 23:30   ` Kees Cook
2020-05-21 23:43     ` Thomas Gleixner
2020-05-21 23:44     ` Kristen Carlson Accardi
2020-05-21 23:44       ` Kristen Carlson Accardi

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