From: Sam Edwards <cfsworks@gmail.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Baruch Siach <baruch@tkos.co.il>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Joey Gouly <joey.gouly@arm.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Sam Edwards <CFSworks@gmail.com>
Subject: [PATCH 1/3] arm64: mm: Cast start/end markers to char *, not u64
Date: Thu, 21 Aug 2025 21:15:36 -0700 [thread overview]
Message-ID: <20250822041538.467514-2-CFSworks@gmail.com> (raw)
In-Reply-To: <20250822041538.467514-1-CFSworks@gmail.com>
There are a few memset() calls in map_kernel.c that cast marker-symbol
addresses to u64 in order to perform pointer subtraction (range size
computation).
Cast them with (char *) instead, aligning with idiomatic C pointer
arithmetic.
This patch provably has no effect at runtime: I have verified that
.text of vmlinux is identical after this change.
Signed-off-by: Sam Edwards <CFSworks@gmail.com>
---
arch/arm64/kernel/pi/map_kernel.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/pi/map_kernel.c b/arch/arm64/kernel/pi/map_kernel.c
index 0f4bd7771859..2b3047860230 100644
--- a/arch/arm64/kernel/pi/map_kernel.c
+++ b/arch/arm64/kernel/pi/map_kernel.c
@@ -179,7 +179,7 @@ static void __init remap_idmap_for_lpa2(void)
* Don't bother with the FDT, we no longer need it after this.
*/
memset(init_idmap_pg_dir, 0,
- (u64)init_idmap_pg_end - (u64)init_idmap_pg_dir);
+ (char *)init_idmap_pg_end - (char *)init_idmap_pg_dir);
create_init_idmap(init_idmap_pg_dir, mask);
dsb(ishst);
@@ -188,7 +188,7 @@ static void __init remap_idmap_for_lpa2(void)
set_ttbr0_for_lpa2((u64)init_idmap_pg_dir);
/* wipe the temporary ID map from memory */
- memset(init_pg_dir, 0, (u64)init_pg_end - (u64)init_pg_dir);
+ memset(init_pg_dir, 0, (char *)init_pg_end - (char *)init_pg_dir);
}
static void __init map_fdt(u64 fdt)
@@ -242,7 +242,7 @@ asmlinkage void __init early_map_kernel(u64 boot_status, void *fdt)
map_fdt((u64)fdt);
/* Clear BSS and the initial page tables */
- memset(__bss_start, 0, (u64)init_pg_end - (u64)__bss_start);
+ memset(__bss_start, 0, (char *)init_pg_end - (char *)__bss_start);
/* Parse the command line for CPU feature overrides */
chosen = fdt_path_offset(fdt, chosen_str);
--
2.49.1
next prev parent reply other threads:[~2025-08-22 11:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-22 4:15 [PATCH 0/3] Type correctness cleanup for ARM64 MMU initialization Sam Edwards
2025-08-22 4:15 ` Sam Edwards [this message]
2025-08-22 4:15 ` [PATCH 2/3] arm64: mm: Make map_fdt() return mapped pointer Sam Edwards
2025-08-22 4:15 ` [PATCH 3/3] arm64: mm: Represent physical memory with phys_addr_t and resource_size_t Sam Edwards
2025-08-23 23:57 ` Sam Edwards
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