linux-kernel - [PATCH 19/29] x86/boot/e820: Standardize e820 table index variable types under 'u32'

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250421185210.3372306-20-mingo@kernel.org>
Date: Mon, 21 Apr 2025 20:51:59 +0200
From: Ingo Molnar <mingo@...nel.org>
To: linux-kernel@...r.kernel.org
Cc: Andy Shevchenko <andy@...nel.org>,
	Arnd Bergmann <arnd@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Juergen Gross <jgross@...e.com>,
	"H . Peter Anvin" <hpa@...or.com>,
	Kees Cook <keescook@...omium.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Mike Rapoport <rppt@...nel.org>,
	Paul Menzel <pmenzel@...gen.mpg.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>,
	David Woodhouse <dwmw@...zon.co.uk>
Subject: [PATCH 19/29] x86/boot/e820: Standardize e820 table index variable types under 'u32'

So we have 'idx' types of 'int' and 'unsigned int', and sometimes
we assign 'u32' fields such as e820_table::nr_entries to these 'int'
values.

While there's no real risk of overflow with these tables, make it
all cleaner by standardizing on a single type: u32.

This also happens to shrink the code a bit:

   text      data      bss        dec        hex    filename
   7745     44072        0      51817       ca69    e820.o.before
   7613     44072        0      51685       c9e5    e820.o.after

Signed-off-by: Ingo Molnar <mingo@...nel.org>
Cc: Andy Shevchenko <andy@...nel.org>
Cc: Arnd Bergmann <arnd@...nel.org>
Cc: David Woodhouse <dwmw@...zon.co.uk>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Kees Cook <keescook@...omium.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Mike Rapoport (Microsoft) <rppt@...nel.org>
---
 arch/x86/kernel/e820.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 919950d0f03d..d55cb77537e7 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -75,7 +75,7 @@ EXPORT_SYMBOL(pci_mem_start);
 static bool _e820__mapped_any(struct e820_table *table,
 			      u64 start, u64 end, enum e820_type type)
 {
-	int idx;
+	u32 idx;
 
 	for (idx = 0; idx < table->nr_entries; idx++) {
 		struct e820_entry *entry = &table->entries[idx];
@@ -110,7 +110,7 @@ EXPORT_SYMBOL_GPL(e820__mapped_any);
 static struct e820_entry *__e820__mapped_all(u64 start, u64 end,
 					     enum e820_type type)
 {
-	int idx;
+	u32 idx;
 
 	for (idx = 0; idx < e820_table->nr_entries; idx++) {
 		struct e820_entry *entry = &e820_table->entries[idx];
@@ -163,7 +163,7 @@ int e820__get_entry_type(u64 start, u64 end)
  */
 static void __init __e820__range_add(struct e820_table *table, u64 start, u64 size, enum e820_type type)
 {
-	int idx = table->nr_entries;
+	u32 idx = table->nr_entries;
 
 	if (idx >= ARRAY_SIZE(table->entries)) {
 		pr_err("too many E820 table entries; ignoring [mem %#010llx-%#010llx]\n",
@@ -236,7 +236,7 @@ static void e820_print_size(u64 size)
 static void __init e820__print_table(const char *who)
 {
 	u64 range_end_prev = 0;
-	int idx;
+	u32 idx;
 
 	for (idx = 0; idx < e820_table->nr_entries; idx++) {
 		struct e820_entry *entry = e820_table->entries + idx;
@@ -524,7 +524,7 @@ static u64 __init
 __e820__range_update(struct e820_table *table, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type)
 {
 	u64 end;
-	unsigned int idx;
+	u32 idx;
 	u64 real_updated_size = 0;
 
 	BUG_ON(old_type == new_type);
@@ -602,7 +602,7 @@ u64 __init e820__range_update_table(struct e820_table *t, u64 start, u64 size,
 /* Remove a range of memory from the E820 table: */
 u64 __init e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
 {
-	int idx;
+	u32 idx;
 	u64 end;
 	u64 real_removed_size = 0;
 
@@ -814,7 +814,7 @@ void __init e820__memory_setup_extended(u64 phys_addr, u32 data_len)
  */
 void __init e820__register_nosave_regions(unsigned long limit_pfn)
 {
-	int idx;
+	u32 idx;
 	u64 last_addr = 0;
 
 	for (idx = 0; idx < e820_table->nr_entries; idx++) {
@@ -839,7 +839,7 @@ void __init e820__register_nosave_regions(unsigned long limit_pfn)
  */
 static int __init e820__register_nvs_regions(void)
 {
-	int idx;
+	u32 idx;
 
 	for (idx = 0; idx < e820_table->nr_entries; idx++) {
 		struct e820_entry *entry = &e820_table->entries[idx];
@@ -890,7 +890,7 @@ u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)
  */
 static unsigned long __init e820__end_ram_pfn(unsigned long limit_pfn)
 {
-	int idx;
+	u32 idx;
 	unsigned long last_pfn = 0;
 	unsigned long max_arch_pfn = MAX_ARCH_PFN;
 
@@ -1145,7 +1145,7 @@ static bool __init e820_device_region(enum e820_type type, struct resource *res)
  */
 void __init e820__reserve_resources(void)
 {
-	int idx;
+	u32 idx;
 	struct resource *res;
 	u64 end;
 
@@ -1210,7 +1210,7 @@ static unsigned long __init ram_alignment(resource_size_t pos)
 
 void __init e820__reserve_resources_late(void)
 {
-	int idx;
+	u32 idx;
 	struct resource *res;
 
 	/*
@@ -1314,7 +1314,7 @@ void __init e820__memory_setup(void)
 
 void __init e820__memblock_setup(void)
 {
-	int idx;
+	u32 idx;
 	u64 end;
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-- 
2.45.2