[patch 3/5] x86/idt: Use proper constants for table sizes

From: Thomas Gleixner
Date: Thu May 28 2020 - 10:56:31 EST


Use the actual struct size to calculate the IDT table sizes instead of two
different hardcoded values.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/kernel/idt.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -51,6 +51,8 @@ struct idt_data {
#define TSKG(_vector, _gdt) \
G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)

+#define IDT_TABLE_SIZE (IDT_ENTRIES * sizeof(gate_desc))
+#define IDT_DEBUG_TABLE_SIZE (16 * sizeof(gate_desc))

static bool idt_setup_done __initdata;

@@ -176,7 +178,7 @@ static const __initconst struct idt_data
gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;

struct desc_ptr idt_descr __ro_after_init = {
- .size = (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1,
+ .size = IDT_TABLE_SIZE - 1,
.address = (unsigned long) idt_table,
};

@@ -202,7 +204,7 @@ static const __initconst struct idt_data
* stack set to DEFAULT_STACK (0). Required for NMI trap handling.
*/
const struct desc_ptr debug_idt_descr = {
- .size = IDT_ENTRIES * 16 - 1,
+ .size = IDT_DEBUG_TABLE_SIZE - 1,
.address = (unsigned long) debug_idt_table,
};
#endif
@@ -304,9 +306,10 @@ void __init idt_setup_ist_traps(void)
*/
void __init idt_setup_debugidt_traps(void)
{
- memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
+ memcpy(&debug_idt_table, &idt_table, IDT_DEBUG_TABLE_SIZE);

- idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts), false);
+ idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts),
+ false);
}
#endif