[PATCH 1/5] powerpc/ptdump: fix addresses display on PPC32

[PATCH 1/5] powerpc/ptdump: fix addresses display on PPC32

[Christophe Leroy]

Commit 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a
shift in the displayed addresses.

Lets revert that change to resync walk_pagetables()'s addr val and
pgd_t pointer for PPC32.

Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/ptdump/ptdump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 6a88a9f585d4..3ad64fc11419 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -27,7 +27,7 @@
 #include "ptdump.h"
 
 #ifdef CONFIG_PPC32
-#define KERN_VIRT_START	PAGE_OFFSET
+#define KERN_VIRT_START	0
 #endif
 
 /*
-- 
2.13.3

[PATCH 2/5] powerpc/ptdump: fix walk_pagetables() address mismatch

[Christophe Leroy]

walk_pagetables() always walk the entire pgdir from address 0
but considers PAGE_OFFSET or KERN_VIRT_START as the starting
address of the walk, resulting in a possible mismatch in the
displayed addresses.

Ex: on PPC32, when KERN_VIRT_START was locally defined as
PAGE_OFFSET, ptdump displayed 0x80000000
instead of 0xc0000000 for the first kernel page,
because 0xc0000000 + 0xc0000000 = 0x80000000

Start the walk at st->start_address instead of starting at 0.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/ptdump/ptdump.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 3ad64fc11419..74ff2bff4ea0 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -299,17 +299,15 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start)
 
 static void walk_pagetables(struct pg_state *st)
 {
-	pgd_t *pgd = pgd_offset_k(0UL);
 	unsigned int i;
-	unsigned long addr;
-
-	addr = st->start_address;
+	unsigned long addr = st->start_address & PGDIR_MASK;
+	pgd_t *pgd = pgd_offset_k(addr);
 
 	/*
 	 * Traverse the linux pagetable structure and dump pages that are in
 	 * the hash pagetable.
 	 */
-	for (i = 0; i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
+	for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) {
 		if (!pgd_none(*pgd) && !pgd_is_leaf(*pgd))
 			/* pgd exists */
 			walk_pud(st, pgd, addr);
-- 
2.13.3

[PATCH 3/5] powerpc/ptdump: drop dummy KERN_VIRT_START on PPC32

[Christophe Leroy]

PPC32 doesn't have KERN_VIRT_START. Make PAGE_OFFSET the
default starting address for the dump, and drop the dummy
definition of KERN_VIRT_START. Only use KERN_VIRT_START for
non radix PPC64.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/ptdump/ptdump.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 74ff2bff4ea0..9a2186c133e6 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -26,10 +26,6 @@
 
 #include "ptdump.h"
 
-#ifdef CONFIG_PPC32
-#define KERN_VIRT_START	0
-#endif
-
 /*
  * To visualise what is happening,
  *
@@ -362,12 +358,13 @@ static int ptdump_show(struct seq_file *m, void *v)
 	struct pg_state st = {
 		.seq = m,
 		.marker = address_markers,
+		.start_address = PAGE_OFFSET,
 	};
 
-	if (radix_enabled())
-		st.start_address = PAGE_OFFSET;
-	else
+#ifdef CONFIG_PPC64
+	if (!radix_enabled())
 		st.start_address = KERN_VIRT_START;
+#endif
 
 	/* Traverse kernel page tables */
 	walk_pagetables(&st);
@@ -405,12 +402,13 @@ void ptdump_check_wx(void)
 		.seq = NULL,
 		.marker = address_markers,
 		.check_wx = true,
+		.start_address = PAGE_OFFSET,
 	};
 
-	if (radix_enabled())
-		st.start_address = PAGE_OFFSET;
-	else
+#ifdef CONFIG_PPC64
+	if (!radix_enabled())
 		st.start_address = KERN_VIRT_START;
+#endif
 
 	walk_pagetables(&st);
 
-- 
2.13.3

[PATCH 4/5] powerpc/ptdump: get out of note_prot_wx() when CONFIG_PPC_DEBUG_WX is not selected.

[Christophe Leroy]

When CONFIG_PPC_DEBUG_WX, note_prot_wx() is useless.

Get out of it early and inconditionnally in that case,
so that GCC can kick all the code out.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/mm/ptdump/ptdump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index 9a2186c133e6..ab6a572202b4 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -177,7 +177,7 @@ static void dump_addr(struct pg_state *st, unsigned long addr)
 
 static void note_prot_wx(struct pg_state *st, unsigned long addr)
 {
-	if (!st->check_wx)
+	if (!IS_ENABLED(CONFIG_PPC_DEBUG_WX) || !st->check_wx)
 		return;
 
 	if (!((st->current_flags & pgprot_val(PAGE_KERNEL_X)) == pgprot_val(PAGE_KERNEL_X)))
-- 
2.13.3

[PATCH 5/5] powerpc/ptdump: drop non vital #ifdefs

[Christophe Leroy]

hashpagetable.c is only compiled when CONFIG_PPC_BOOK3S_64 is
defined, so drop the test and its 'else' branch.

Use IS_ENABLED(CONFIG_PPC_PSERIES) instead of #ifdef, this allows the
code to be checked at any build. It is still optimised out by GCC.

Use IS_ENABLED(CONFIG_PPC_64K_PAGES) instead of #ifdef.

Use IS_ENABLED(CONFIG_SPARSEMEN_VMEMMAP) instead of #ifdef.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/plpar_wrappers.h |  6 ++++++
 arch/powerpc/mm/ptdump/hashpagetable.c    | 24 +++++++++---------------
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/plpar_wrappers.h b/arch/powerpc/include/asm/plpar_wrappers.h
index cff5a411e595..4497c8afb573 100644
--- a/arch/powerpc/include/asm/plpar_wrappers.h
+++ b/arch/powerpc/include/asm/plpar_wrappers.h
@@ -340,6 +340,12 @@ static inline long plpar_set_ciabr(unsigned long ciabr)
 {
 	return 0;
 }
+
+static inline long plpar_pte_read_4(unsigned long flags, unsigned long ptex,
+				    unsigned long *ptes)
+{
+	return 0;
+}
 #endif /* CONFIG_PPC_PSERIES */
 
 #endif /* _ASM_POWERPC_PLPAR_WRAPPERS_H */
diff --git a/arch/powerpc/mm/ptdump/hashpagetable.c b/arch/powerpc/mm/ptdump/hashpagetable.c
index 72f0e4a3d839..a07278027c6f 100644
--- a/arch/powerpc/mm/ptdump/hashpagetable.c
+++ b/arch/powerpc/mm/ptdump/hashpagetable.c
@@ -237,7 +237,6 @@ static int native_find(unsigned long ea, int psize, bool primary, u64 *v, u64
 	return -1;
 }
 
-#ifdef CONFIG_PPC_PSERIES
 static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *r)
 {
 	struct hash_pte ptes[4];
@@ -274,7 +273,6 @@ static int pseries_find(unsigned long ea, int psize, bool primary, u64 *v, u64 *
 	}
 	return -1;
 }
-#endif
 
 static void decode_r(int bps, unsigned long r, unsigned long *rpn, int *aps,
 		unsigned long *lp_bits)
@@ -316,10 +314,9 @@ static void decode_r(int bps, unsigned long r, unsigned long *rpn, int *aps,
 static int base_hpte_find(unsigned long ea, int psize, bool primary, u64 *v,
 			  u64 *r)
 {
-#ifdef CONFIG_PPC_PSERIES
-	if (firmware_has_feature(FW_FEATURE_LPAR))
+	if (IS_ENABLED(CONFIG_PPC_PSERIES) && firmware_has_feature(FW_FEATURE_LPAR))
 		return pseries_find(ea, psize, primary, v, r);
-#endif
+
 	return native_find(ea, psize, primary, v, r);
 }
 
@@ -386,12 +383,13 @@ static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start)
 			psize = mmu_vmalloc_psize;
 		else
 			psize = mmu_io_psize;
-#ifdef CONFIG_PPC_64K_PAGES
+
 		/* check for secret 4K mappings */
-		if (((pteval & H_PAGE_COMBO) == H_PAGE_COMBO) ||
-			((pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN))
+		if (IS_ENABLED(CONFIG_PPC_64K_PAGES) &&
+		    ((pteval & H_PAGE_COMBO) == H_PAGE_COMBO ||
+		     (pteval & H_PAGE_4K_PFN) == H_PAGE_4K_PFN))
 			psize = mmu_io_psize;
-#endif
+
 		/* check for hashpte */
 		status = hpte_find(st, addr, psize);
 
@@ -469,9 +467,10 @@ static void walk_linearmapping(struct pg_state *st)
 
 static void walk_vmemmap(struct pg_state *st)
 {
-#ifdef CONFIG_SPARSEMEM_VMEMMAP
 	struct vmemmap_backing *ptr = vmemmap_list;
 
+	if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
+		return;
 	/*
 	 * Traverse the vmemmaped memory and dump pages that are in the hash
 	 * pagetable.
@@ -481,7 +480,6 @@ static void walk_vmemmap(struct pg_state *st)
 		ptr = ptr->list;
 	}
 	seq_puts(st->seq, "---[ vmemmap end ]---\n");
-#endif
 }
 
 static void populate_markers(void)
@@ -495,11 +493,7 @@ static void populate_markers(void)
 	address_markers[6].start_address = PHB_IO_END;
 	address_markers[7].start_address = IOREMAP_BASE;
 	address_markers[8].start_address = IOREMAP_END;
-#ifdef CONFIG_PPC_BOOK3S_64
 	address_markers[9].start_address =  H_VMEMMAP_START;
-#else
-	address_markers[9].start_address =  VMEMMAP_BASE;
-#endif
 }
 
 static int ptdump_show(struct seq_file *m, void *v)
-- 
2.13.3

Re: [PATCH 1/5] powerpc/ptdump: fix addresses display on PPC32

[Christophe Leroy]

Michael,

Le 14/08/2019 à 14:36, Christophe Leroy a écrit :
> Commit 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
> wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a
> shift in the displayed addresses.
> 
> Lets revert that change to resync walk_pagetables()'s addr val and
> pgd_t pointer for PPC32.
> 
> Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")

Either this patch or patch 2 of the series has to go into fixes.

If you prefer next patch for fixes, then this one can be squashed into 
patch 3 which drops the PPC32 hacked definition of KERN_VIRT_START

Christophe

> Cc: stable@vger.kernel.org
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>   arch/powerpc/mm/ptdump/ptdump.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
> index 6a88a9f585d4..3ad64fc11419 100644
> --- a/arch/powerpc/mm/ptdump/ptdump.c
> +++ b/arch/powerpc/mm/ptdump/ptdump.c
> @@ -27,7 +27,7 @@
>   #include "ptdump.h"
>   
>   #ifdef CONFIG_PPC32
> -#define KERN_VIRT_START	PAGE_OFFSET
> +#define KERN_VIRT_START	0
>   #endif
>   
>   /*
> 

Re: [PATCH 1/5] powerpc/ptdump: fix addresses display on PPC32

[Michael Ellerman]

On Wed, 2019-08-14 at 12:36:09 UTC, Christophe Leroy wrote:
> Commit 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
> wrongly changed KERN_VIRT_START from 0 to PAGE_OFFSET, leading to a
> shift in the displayed addresses.
> 
> Lets revert that change to resync walk_pagetables()'s addr val and
> pgd_t pointer for PPC32.
> 
> Fixes: 453d87f6a8ae ("powerpc/mm: Warn if W+X pages found on boot")
> Cc: stable@vger.kernel.org
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/7c7a532ba3fc51bf9527d191fb410786c1fdc73c

cheers