Commit 60e14be9 authored by Kuan-Wei Chiu's avatar Kuan-Wei Chiu Committed by Wen Zhiwei
Browse files

scripts/sorttable: fix orc_sort_cmp() to maintain symmetry and transitivity 

stable inclusion
from stable-v6.6.70
commit c9818b61d0a859ecec77ec3253b418dc89e5e695
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBOHV1

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c9818b61d0a859ecec77ec3253b418dc89e5e695

--------------------------------

commit 0210d251162f4033350a94a43f95b1c39ec84a90 upstream.

The orc_sort_cmp() function, used with qsort(), previously violated the
symmetry and transitivity rules required by the C standard.  Specifically,
when both entries are ORC_TYPE_UNDEFINED, it could result in both a < b
and b < a, which breaks the required symmetry and transitivity.  This can
lead to undefined behavior and incorrect sorting results, potentially
causing memory corruption in glibc implementations [1].

Symmetry: If x < y, then y > x.
Transitivity: If x < y and y < z, then x < z.

Fix the comparison logic to return 0 when both entries are
ORC_TYPE_UNDEFINED, ensuring compliance with qsort() requirements.

Link: https://www.qualys.com/2024/01/30/qsort.txt [1]
Link: https://lkml.kernel.org/r/20241226140332.2670689-1-visitorckw@gmail.com


Fixes: 57fa1899 ("scripts/sorttable: Implement build-time ORC unwind table sorting")
Fixes: fb799447 ("x86,objtool: Split UNWIND_HINT_EMPTY in two")
Signed-off-by: default avatarKuan-Wei Chiu <visitorckw@gmail.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: <chuang@cs.nycu.edu.tw>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shile Zhang <shile.zhang@linux.alibaba.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent b89df13a

scripts/sorttable.h

+4 −1
Original line number Diff line number Diff line
@@ -110,7 +110,7 @@ static inline unsigned long orc_ip(const int *ip) 


static int orc_sort_cmp(const void *_a, const void *_b)

{

	struct orc_entry *orc_a;

	struct orc_entry *orc_a, *orc_b;

	const int *a = g_orc_ip_table + *(int *)_a;

	const int *b = g_orc_ip_table + *(int *)_b;

	unsigned long a_val = orc_ip(a);
@@ -128,6 +128,9 @@ static int orc_sort_cmp(const void *_a, const void *_b) 
	 * whitelisted .o files which didn't get objtool generation.

	 */

	orc_a = g_orc_table + (a - g_orc_ip_table);

	orc_b = g_orc_table + (b - g_orc_ip_table);

	if (orc_a->type == ORC_TYPE_UNDEFINED && orc_b->type == ORC_TYPE_UNDEFINED)

		return 0;

	return orc_a->type == ORC_TYPE_UNDEFINED ? -1 : 1;

}