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From:   andrey.konovalov@linux.dev
To:     Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com, Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Florian Mayer <fmayer@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH 27/32] kasan: introduce complete_report_info
Date:   Mon, 13 Jun 2022 22:14:18 +0200
Message-Id: <dcc8dd2856119f660f7402977de9da2b2419b175.1655150842.git.andreyknvl@google.com>
In-Reply-To: <cover.1655150842.git.andreyknvl@google.com>
References: <cover.1655150842.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@google.com>

Introduce a complete_report_info() function that fills in the
first_bad_addr field of kasan_report_info instead of doing it in
kasan_report_*().

This function will be extended in the next patch.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 mm/kasan/kasan.h  |  5 ++++-
 mm/kasan/report.c | 17 +++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index e3f100833154..0261d1530055 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -147,12 +147,15 @@ static inline bool kasan_requires_meta(void)
 #define META_ROWS_AROUND_ADDR 2
 
 struct kasan_report_info {
+	/* Filled in by kasan_report_*(). */
 	void *access_addr;
-	void *first_bad_addr;
 	size_t access_size;
 	bool is_free;
 	bool is_write;
 	unsigned long ip;
+
+	/* Filled in by the common reporting code. */
+	void *first_bad_addr;
 };
 
 /* Do not change the struct layout: compiler ABI. */
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index cc35c8c1a367..214ba7cb654c 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -407,6 +407,17 @@ static void print_report(struct kasan_report_info *info)
 	}
 }
 
+static void complete_report_info(struct kasan_report_info *info)
+{
+	void *addr = kasan_reset_tag(info->access_addr);
+
+	if (info->is_free)
+		info->first_bad_addr = addr;
+	else
+		info->first_bad_addr = kasan_find_first_bad_addr(
+					info->access_addr, info->access_size);
+}
+
 void kasan_report_invalid_free(void *ptr, unsigned long ip)
 {
 	unsigned long flags;
@@ -423,12 +434,13 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip)
 	start_report(&flags, true);
 
 	info.access_addr = ptr;
-	info.first_bad_addr = kasan_reset_tag(ptr);
 	info.access_size = 0;
 	info.is_write = false;
 	info.is_free = true;
 	info.ip = ip;
 
+	complete_report_info(&info);
+
 	print_report(&info);
 
 	end_report(&flags, ptr);
@@ -456,12 +468,13 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write,
 	start_report(&irq_flags, true);
 
 	info.access_addr = ptr;
-	info.first_bad_addr = kasan_find_first_bad_addr(ptr, size);
 	info.access_size = size;
 	info.is_write = is_write;
 	info.is_free = false;
 	info.ip = ip;
 
+	complete_report_info(&info);
+
 	print_report(&info);
 
 	end_report(&irq_flags, ptr);
-- 
2.25.1