[PATCH 1/3] x86/pti: Move pti_init() code out of __init

From: Joerg Roedel
Date: Tue Jul 03 2018 - 07:53:01 EST


From: Joerg Roedel <jroedel@xxxxxxx>

This removes the __init annotations from pti_init() and everything it
calls on x86. The pti_init() function sets up the kernel-mappings
visible in the user-space page-table when PTI is enabled, which only
makes sense after the relevant kernel mappings have been finished.

The kernel mappings are finished when the appropriate read-only and
no-execute protections are established for the kernel text, rodata and
data sections, which happens after the init-code/data has been freed by
the kernel.

So to call pti_init() at the right place it can't be __init anymore.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/entry/vsyscall/vsyscall_64.c | 2 +-
arch/x86/mm/pti.c | 16 ++++++++--------
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 82ed001..6cd5cbf 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -340,7 +340,7 @@ int in_gate_area_no_mm(unsigned long addr)
* vsyscalls but leave the page not present. If so, we skip calling
* this.
*/
-void __init set_vsyscall_pgtable_user_bits(pgd_t *root)
+void set_vsyscall_pgtable_user_bits(pgd_t *root)
{
pgd_t *pgd;
p4d_t *p4d;
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index 4d418e7..8a80522 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -234,7 +234,7 @@ static pmd_t *pti_user_pagetable_walk_pmd(unsigned long address)
*
* Returns a pointer to a PTE on success, or NULL on failure.
*/
-static __init pte_t *pti_user_pagetable_walk_pte(unsigned long address)
+static pte_t *pti_user_pagetable_walk_pte(unsigned long address)
{
gfp_t gfp = (GFP_KERNEL | __GFP_NOTRACK | __GFP_ZERO);
pmd_t *pmd = pti_user_pagetable_walk_pmd(address);
@@ -262,7 +262,7 @@ static __init pte_t *pti_user_pagetable_walk_pte(unsigned long address)
return pte;
}

-static void __init pti_setup_vsyscall(void)
+static void pti_setup_vsyscall(void)
{
pte_t *pte, *target_pte;
unsigned int level;
@@ -279,7 +279,7 @@ static void __init pti_setup_vsyscall(void)
set_vsyscall_pgtable_user_bits(kernel_to_user_pgdp(swapper_pg_dir));
}
#else
-static void __init pti_setup_vsyscall(void) { }
+static void pti_setup_vsyscall(void) { }
#endif

static void
@@ -348,7 +348,7 @@ pti_clone_pmds(unsigned long start, unsigned long end, pmdval_t clear)
* Clone a single p4d (i.e. a top-level entry on 4-level systems and a
* next-level entry on 5-level systems.
*/
-static void __init pti_clone_p4d(unsigned long addr)
+static void pti_clone_p4d(unsigned long addr)
{
p4d_t *kernel_p4d, *user_p4d;
pgd_t *kernel_pgd;
@@ -362,7 +362,7 @@ static void __init pti_clone_p4d(unsigned long addr)
/*
* Clone the CPU_ENTRY_AREA into the user space visible page table.
*/
-static void __init pti_clone_user_shared(void)
+static void pti_clone_user_shared(void)
{
pti_clone_p4d(CPU_ENTRY_AREA_BASE);
}
@@ -370,7 +370,7 @@ static void __init pti_clone_user_shared(void)
/*
* Clone the ESPFIX P4D into the user space visible page table
*/
-static void __init pti_setup_espfix64(void)
+static void pti_setup_espfix64(void)
{
#ifdef CONFIG_X86_ESPFIX64
pti_clone_p4d(ESPFIX_BASE_ADDR);
@@ -380,7 +380,7 @@ static void __init pti_setup_espfix64(void)
/*
* Clone the populated PMDs of the entry and irqentry text and force it RO.
*/
-static void __init pti_clone_entry_text(void)
+static void pti_clone_entry_text(void)
{
pti_clone_pmds((unsigned long) __entry_text_start,
(unsigned long) __irqentry_text_end,
@@ -486,7 +486,7 @@ void pti_set_kernel_image_nonglobal(void)
/*
* Initialize kernel page table isolation
*/
-void __init pti_init(void)
+void pti_init(void)
{
if (!static_cpu_has(X86_FEATURE_PTI))
return;
--
2.7.4