of: Fix truncation of memory sizes on 32-bit platforms
authorGeert Uytterhoeven <geert+renesas@glider.be>
Wed, 16 Jun 2021 09:27:44 +0000 (11:27 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 14 Jul 2021 14:56:46 +0000 (16:56 +0200)
[ Upstream commit 2892d8a00d23d511a0591ac4b2ff3f050ae1f004 ]

Variable "size" has type "phys_addr_t", which can be either 32-bit or
64-bit on 32-bit systems, while "unsigned long" is always 32-bit on
32-bit systems.  Hence the cast in

    (unsigned long)size / SZ_1M

may truncate a 64-bit size to 32-bit, as casts have a higher operator
precedence than divisions.

Fix this by inverting the order of the cast and division, which should
be safe for memory blocks smaller than 4 PiB.  Note that the division is
actually a shift, as SZ_1M is a power-of-two constant, hence there is no
need to use div_u64().

While at it, use "%lu" to format "unsigned long".

Fixes: e8d9d1f5485b52ec ("drivers: of: add initialization code for static reserved memory")
Fixes: 3f0c8206644836e4 ("drivers: of: add initialization code for dynamic reserved memory")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/4a1117e72d13d26126f57be034c20dac02f1e915.1623835273.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/of/fdt.c
drivers/of/of_reserved_mem.c

index f2e6970..57ff31b 100644 (file)
@@ -501,11 +501,11 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 
                if (size &&
                    early_init_dt_reserve_memory_arch(base, size, nomap) == 0)
-                       pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %ld MiB\n",
-                               uname, &base, (unsigned long)size / SZ_1M);
+                       pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
+                               uname, &base, (unsigned long)(size / SZ_1M));
                else
-                       pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %ld MiB\n",
-                               uname, &base, (unsigned long)size / SZ_1M);
+                       pr_info("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
+                               uname, &base, (unsigned long)(size / SZ_1M));
 
                len -= t_len;
                if (first) {
index a7fbc5e..6c95bbd 100644 (file)
@@ -134,9 +134,9 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
                        ret = early_init_dt_alloc_reserved_memory_arch(size,
                                        align, start, end, nomap, &base);
                        if (ret == 0) {
-                               pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
+                               pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
                                        uname, &base,
-                                       (unsigned long)size / SZ_1M);
+                                       (unsigned long)(size / SZ_1M));
                                break;
                        }
                        len -= t_len;
@@ -146,8 +146,8 @@ static int __init __reserved_mem_alloc_size(unsigned long node,
                ret = early_init_dt_alloc_reserved_memory_arch(size, align,
                                                        0, 0, nomap, &base);
                if (ret == 0)
-                       pr_debug("allocated memory for '%s' node: base %pa, size %ld MiB\n",
-                               uname, &base, (unsigned long)size / SZ_1M);
+                       pr_debug("allocated memory for '%s' node: base %pa, size %lu MiB\n",
+                               uname, &base, (unsigned long)(size / SZ_1M));
        }
 
        if (base == 0) {