[PATCH v2 24/37] powerpc: Rely on address instead of pte_user()

From: Christophe Leroy
Date: Mon Sep 25 2023 - 14:34:16 EST


pte_user() may return 'false' when a user page is PAGE_NONE.

In that case it is still a user page and needs to be handled
as such. So use is_kernel_addr() instead.

And remove "user" text from ptdump as ptdump only dumps
kernel tables.

Note: no change done for book3s/64 which still has it
'priviledge' bit.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/nohash/pgtable.h | 2 +-
arch/powerpc/mm/book3s32/mmu.c | 4 ++--
arch/powerpc/mm/nohash/e500.c | 2 +-
arch/powerpc/mm/pgtable.c | 22 +++++++++++-----------
arch/powerpc/mm/ptdump/8xx.c | 5 -----
arch/powerpc/mm/ptdump/shared.c | 5 -----
6 files changed, 15 insertions(+), 25 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 9619beae4454..200f2dbf48e2 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -58,7 +58,7 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p

*p = __pte(new);

- if (IS_ENABLED(CONFIG_44x) && (old & _PAGE_USER) && (old & _PAGE_EXEC))
+ if (IS_ENABLED(CONFIG_44x) && !is_kernel_addr(addr) && (old & _PAGE_EXEC))
icache_44x_need_flush = 1;

/* huge pages use the old page table lock */
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 850783cfa9c7..d1041c946ce2 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -127,7 +127,7 @@ static void setibat(int index, unsigned long virt, phys_addr_t phys,
wimgxpp = (flags & _PAGE_COHERENT) | (_PAGE_EXEC ? BPP_RX : BPP_XX);
bat[0].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */
bat[0].batl = BAT_PHYS_ADDR(phys) | wimgxpp;
- if (flags & _PAGE_USER)
+ if (!is_kernel_addr(virt))
bat[0].batu |= 1; /* Vp = 1 */
}

@@ -280,7 +280,7 @@ void __init setbat(int index, unsigned long virt, phys_addr_t phys,
wimgxpp |= (flags & _PAGE_RW)? BPP_RW: BPP_RX;
bat[1].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */
bat[1].batl = BAT_PHYS_ADDR(phys) | wimgxpp;
- if (flags & _PAGE_USER)
+ if (!is_kernel_addr(virt))
bat[1].batu |= 1; /* Vp = 1 */
if (flags & _PAGE_GUARDED) {
/* G bit must be zero in IBATs */
diff --git a/arch/powerpc/mm/nohash/e500.c b/arch/powerpc/mm/nohash/e500.c
index 40a4e69ae1a9..5b7d7a932bfd 100644
--- a/arch/powerpc/mm/nohash/e500.c
+++ b/arch/powerpc/mm/nohash/e500.c
@@ -122,7 +122,7 @@ static void settlbcam(int index, unsigned long virt, phys_addr_t phys,
TLBCAM[index].MAS7 = (u64)phys >> 32;

/* Below is unlikely -- only for large user pages or similar */
- if (pte_user(__pte(flags))) {
+ if (!is_kernel_addr(virt)) {
TLBCAM[index].MAS3 |= MAS3_UR;
TLBCAM[index].MAS3 |= (flags & _PAGE_EXEC) ? MAS3_UX : 0;
TLBCAM[index].MAS3 |= (flags & _PAGE_RW) ? MAS3_UW : 0;
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 3f86fd217690..781a68c69c2f 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -46,13 +46,13 @@ static inline int is_exec_fault(void)
* and we avoid _PAGE_SPECIAL and cache inhibited pte. We also only do that
* on userspace PTEs
*/
-static inline int pte_looks_normal(pte_t pte)
+static inline int pte_looks_normal(pte_t pte, unsigned long addr)
{

if (pte_present(pte) && !pte_special(pte)) {
if (pte_ci(pte))
return 0;
- if (pte_user(pte))
+ if (!is_kernel_addr(addr))
return 1;
}
return 0;
@@ -79,11 +79,11 @@ static struct folio *maybe_pte_to_folio(pte_t pte)
* support falls into the same category.
*/

-static pte_t set_pte_filter_hash(pte_t pte)
+static pte_t set_pte_filter_hash(pte_t pte, unsigned long addr)
{
pte = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
- if (pte_looks_normal(pte) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) ||
- cpu_has_feature(CPU_FTR_NOEXECUTE))) {
+ if (pte_looks_normal(pte, addr) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) ||
+ cpu_has_feature(CPU_FTR_NOEXECUTE))) {
struct folio *folio = maybe_pte_to_folio(pte);
if (!folio)
return pte;
@@ -97,7 +97,7 @@ static pte_t set_pte_filter_hash(pte_t pte)

#else /* CONFIG_PPC_BOOK3S */

-static pte_t set_pte_filter_hash(pte_t pte) { return pte; }
+static pte_t set_pte_filter_hash(pte_t pte, unsigned long addr) { return pte; }

#endif /* CONFIG_PPC_BOOK3S */

@@ -105,7 +105,7 @@ static pte_t set_pte_filter_hash(pte_t pte) { return pte; }
* as we don't have two bits to spare for _PAGE_EXEC and _PAGE_HWEXEC so
* instead we "filter out" the exec permission for non clean pages.
*/
-static inline pte_t set_pte_filter(pte_t pte)
+static inline pte_t set_pte_filter(pte_t pte, unsigned long addr)
{
struct folio *folio;

@@ -113,10 +113,10 @@ static inline pte_t set_pte_filter(pte_t pte)
return pte;

if (mmu_has_feature(MMU_FTR_HPTE_TABLE))
- return set_pte_filter_hash(pte);
+ return set_pte_filter_hash(pte, addr);

/* No exec permission in the first place, move on */
- if (!pte_exec(pte) || !pte_looks_normal(pte))
+ if (!pte_exec(pte) || !pte_looks_normal(pte, addr))
return pte;

/* If you set _PAGE_EXEC on weird pages you're on your own */
@@ -200,7 +200,7 @@ void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
* this context might not have been activated yet when this
* is called.
*/
- pte = set_pte_filter(pte);
+ pte = set_pte_filter(pte, addr);

/* Perform the setting of the PTE */
arch_enter_lazy_mmu_mode();
@@ -301,7 +301,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_
*/
VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));

- pte = set_pte_filter(pte);
+ pte = set_pte_filter(pte, addr);

val = pte_val(pte);

diff --git a/arch/powerpc/mm/ptdump/8xx.c b/arch/powerpc/mm/ptdump/8xx.c
index fac932eb8f9a..b5c79b11ea3c 100644
--- a/arch/powerpc/mm/ptdump/8xx.c
+++ b/arch/powerpc/mm/ptdump/8xx.c
@@ -20,11 +20,6 @@ static const struct flag_info flag_array[] = {
#endif
.set = "huge",
.clear = " ",
- }, {
- .mask = _PAGE_SH,
- .val = 0,
- .set = "user",
- .clear = " ",
}, {
.mask = _PAGE_RO | _PAGE_NA,
.val = 0,
diff --git a/arch/powerpc/mm/ptdump/shared.c b/arch/powerpc/mm/ptdump/shared.c
index f884760ca5cf..5ff101654c45 100644
--- a/arch/powerpc/mm/ptdump/shared.c
+++ b/arch/powerpc/mm/ptdump/shared.c
@@ -11,11 +11,6 @@

static const struct flag_info flag_array[] = {
{
- .mask = _PAGE_USER,
- .val = _PAGE_USER,
- .set = "user",
- .clear = " ",
- }, {
.mask = _PAGE_RW,
.val = 0,
.set = "r ",
--
2.41.0