From c351828bf35121628461095eeb25ea2152e98d38 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Mon, 21 Nov 2022 19:32:18 -0800
Subject: [PATCH] v0.9.7 backport: MR!1314 ("create-diff-object: fix
 __UNIQUE_ID() variable correlation")

commit 901445a54fcecbd6852b79878e67153c5048602e
Author: Josh Poimboeuf <jpoimboe@redhat.com>
Date:   Mon Nov 21 19:32:18 2022 -0800

    create-diff-object: fix __UNIQUE_ID() variable correlation

    kpatch_mangled_strcmp() only ignores the digits after the period, but in
    the case of __UNIQUE_ID(), the symbol names have random digits before
    the period due to the use of `__COUNTER__`.  Make sure such symbols are
    properly correlated.

    Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

Signed-off-by: Yannick Cote <ycote@redhat.com>
---
 kpatch-build/create-diff-object.c | 32 +++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/kpatch-build/create-diff-object.c b/kpatch-build/create-diff-object.c
index 360441111c5e..7106b67cfd25 100644
--- a/kpatch-build/create-diff-object.c
+++ b/kpatch-build/create-diff-object.c
@@ -396,6 +396,35 @@ static bool has_digit_tail(char *tail)
 	return false;
 }
 
+/*
+ * Hack for __UNIQUE_ID().  The following should match:
+ *
+ *   __UNIQUE_ID_ddebug1131.186
+ *   __UNIQUE_ID_ddebug1132.187
+ */
+static int __kpatch_unique_id_strcmp(char *s1, char *s2)
+{
+	/* match '__UNIQUE_ID_ddebug' */
+	while (*s1 == *s2) {
+		if (!*s1)
+			return 0;
+		s1++;
+		s2++;
+	}
+
+	/* skip digits before '.' or EOL */
+	while (isdigit(*s1))
+		s1++;
+	while (isdigit(*s2))
+		s2++;
+
+	if ((!*s1 || has_digit_tail(s1)) &&
+	    (!*s2 || has_digit_tail(s2)))
+		return 0;
+
+	return 1;
+}
+
 /*
  * This is like strcmp, but for gcc-mangled symbols.  It skips the comparison
  * of any substring which consists of '.' followed by any number of digits.
@@ -409,6 +438,9 @@ static int kpatch_mangled_strcmp(char *s1, char *s2)
 	if (strstr(s1, ".str1."))
 		return strcmp(s1, s2);
 
+	if (!strncmp(s1, "__UNIQUE_ID_", 12))
+		return __kpatch_unique_id_strcmp(s1, s2);
+
 	while (*s1 == *s2) {
 		if (!*s1)
 			return 0;
-- 
2.38.1