[PATCH v3 2/2] x86/head64: Replace pointer fixups with RIP_RELATIVE_ADDR()
From: Kevin Loughlin
Date: Tue Jan 30 2024 - 17:09:25 EST
Now that we have RIP_RELATIVE_ADDR(), we can replace the "fixup_*()"
family of functions in head64.c with the new macro for cleaner code.
Signed-off-by: Kevin Loughlin <kevinloughlin@xxxxxxxxxx>
---
arch/x86/kernel/head64.c | 63 +++++++++++++++-------------------------
1 file changed, 24 insertions(+), 39 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index d159239997f4..e782149eefc4 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -85,23 +85,8 @@ static struct desc_ptr startup_gdt_descr __initdata = {
.address = 0,
};
-static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
-{
- return ptr - (void *)_text + (void *)physaddr;
-}
-
-static unsigned long __head *fixup_long(void *ptr, unsigned long physaddr)
-{
- return fixup_pointer(ptr, physaddr);
-}
-
#ifdef CONFIG_X86_5LEVEL
-static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
-{
- return fixup_pointer(ptr, physaddr);
-}
-
-static bool __head check_la57_support(unsigned long physaddr)
+static bool __head check_la57_support(void)
{
/*
* 5-level paging is detected and enabled at kernel decompression
@@ -110,17 +95,17 @@ static bool __head check_la57_support(unsigned long physaddr)
if (!(native_read_cr4() & X86_CR4_LA57))
return false;
- *fixup_int(&__pgtable_l5_enabled, physaddr) = 1;
- *fixup_int(&pgdir_shift, physaddr) = 48;
- *fixup_int(&ptrs_per_p4d, physaddr) = 512;
- *fixup_long(&page_offset_base, physaddr) = __PAGE_OFFSET_BASE_L5;
- *fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE_L5;
- *fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE_L5;
+ *((unsigned int *)RIP_RELATIVE_ADDR(__pgtable_l5_enabled)) = 1;
+ *((unsigned int *)RIP_RELATIVE_ADDR(pgdir_shift)) = 48;
+ *((unsigned int *)RIP_RELATIVE_ADDR(ptrs_per_p4d)) = 512;
+ *((unsigned long *)RIP_RELATIVE_ADDR(page_offset_base)) = __PAGE_OFFSET_BASE_L5;
+ *((unsigned long *)RIP_RELATIVE_ADDR(vmalloc_base)) = __VMALLOC_BASE_L5;
+ *((unsigned long *)RIP_RELATIVE_ADDR(vmemmap_base)) = __VMEMMAP_BASE_L5;
return true;
}
#else
-static bool __head check_la57_support(unsigned long physaddr)
+static bool __head check_la57_support(void)
{
return false;
}
@@ -175,8 +160,8 @@ static unsigned long __head sme_postprocess_startup(struct boot_params *bp, pmdv
* Code in __startup_64() can be relocated during execution, but the compiler
* doesn't have to generate PC-relative relocations when accessing globals from
* that function. Clang actually does not generate them, which leads to
- * boot-time crashes. To work around this problem, every global pointer must
- * be adjusted using fixup_pointer() or RIP_RELATIVE_ADDR().
+ * boot-time crashes. To work around this problem, every global variable access
+ * must be adjusted using RIP_RELATIVE_ADDR().
*/
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
@@ -194,7 +179,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
int i;
unsigned int *next_pgt_ptr;
- la57 = check_la57_support(physaddr);
+ la57 = check_la57_support();
/* Is the address too large? */
if (physaddr >> MAX_PHYSMEM_BITS)
@@ -215,7 +200,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
/* Fixup the physical addresses in the page table */
- pgd = fixup_pointer(early_top_pgt, physaddr);
+ pgd = RIP_RELATIVE_ADDR(early_top_pgt);
p = pgd + pgd_index(__START_KERNEL_map);
if (la57)
*p = (unsigned long)level4_kernel_pgt;
@@ -224,15 +209,15 @@ unsigned long __head __startup_64(unsigned long physaddr,
*p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
if (la57) {
- p4d = fixup_pointer(level4_kernel_pgt, physaddr);
+ p4d = RIP_RELATIVE_ADDR(level4_kernel_pgt);
p4d[511] += load_delta;
}
- pud = fixup_pointer(level3_kernel_pgt, physaddr);
+ pud = RIP_RELATIVE_ADDR(level3_kernel_pgt);
pud[510] += load_delta;
pud[511] += load_delta;
- pmd = fixup_pointer(level2_fixmap_pgt, physaddr);
+ pmd = RIP_RELATIVE_ADDR(level2_fixmap_pgt);
for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--)
pmd[i] += load_delta;
@@ -243,8 +228,8 @@ unsigned long __head __startup_64(unsigned long physaddr,
* it avoids problems around wraparound.
*/
- next_pgt_ptr = fixup_pointer(&next_early_pgt, physaddr);
- early_dynamic_pgts_ptr = fixup_pointer(early_dynamic_pgts, physaddr);
+ early_dynamic_pgts_ptr = RIP_RELATIVE_ADDR(early_dynamic_pgts);
+ next_pgt_ptr = RIP_RELATIVE_ADDR(next_early_pgt);
pud = (pudval_t *) early_dynamic_pgts_ptr[(*next_pgt_ptr)++];
pmd = (pmdval_t *) early_dynamic_pgts_ptr[(*next_pgt_ptr)++];
@@ -272,7 +257,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
/* Filter out unsupported __PAGE_KERNEL_* bits: */
- mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
+ mask_ptr = RIP_RELATIVE_ADDR(__supported_pte_mask);
pmd_entry &= *mask_ptr;
pmd_entry += sme_me_mask_fixed_up;
pmd_entry += physaddr;
@@ -299,7 +284,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
* error, causing the BIOS to halt the system.
*/
- pmd = fixup_pointer(level2_kernel_pgt, physaddr);
+ pmd = RIP_RELATIVE_ADDR(level2_kernel_pgt);
/* invalidate pages before the kernel image */
for (i = 0; i < pmd_index((unsigned long)_text); i++)
@@ -318,7 +303,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
* Fixup phys_base - remove the memory encryption mask to obtain
* the true physical address.
*/
- *fixup_long(&phys_base, physaddr) += load_delta - sme_me_mask_fixed_up;
+ *((unsigned long *)RIP_RELATIVE_ADDR(phys_base)) += load_delta - sme_me_mask_fixed_up;
return sme_postprocess_startup(bp, pmd);
}
@@ -594,15 +579,15 @@ static void set_bringup_idt_handler(gate_desc *idt, int n, void *handler)
/* This runs while still in the direct mapping */
static void __head startup_64_load_idt(unsigned long physbase)
{
- struct desc_ptr *desc = fixup_pointer(&bringup_idt_descr, physbase);
- gate_desc *idt = fixup_pointer(bringup_idt_table, physbase);
+ struct desc_ptr *desc = RIP_RELATIVE_ADDR(bringup_idt_descr);
+ gate_desc *idt = RIP_RELATIVE_ADDR(bringup_idt_table);
if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
void *handler;
/* VMM Communication Exception */
- handler = fixup_pointer(vc_no_ghcb, physbase);
+ handler = RIP_RELATIVE_ADDR(vc_no_ghcb);
set_bringup_idt_handler(idt, X86_TRAP_VC, handler);
}
@@ -629,7 +614,7 @@ void early_setup_idt(void)
void __head startup_64_setup_env(unsigned long physbase)
{
/* Load GDT */
- startup_gdt_descr.address = (unsigned long)fixup_pointer(startup_gdt, physbase);
+ startup_gdt_descr.address = (unsigned long)RIP_RELATIVE_ADDR(startup_gdt);
native_load_gdt(&startup_gdt_descr);
/* New GDT is live - reload data segment registers */
--
2.43.0.429.g432eaa2c6b-goog