[PATCH v1 3/8] powerpc: Set user/kernel boundary at TASK_SIZE instead of PAGE_OFFSET

From: Christophe Leroy
Date: Fri Jun 19 2020 - 12:09:55 EST


User space stops at TASK_SIZE. At the moment, kernel space starts
at PAGE_OFFSET.

In order to use space between TASK_SIZE and PAGE_OFFSET for modules,
make TASK_SIZE the limit between user and kernel space.

Note that fault.c already considers TASK_SIZE as the boundary between
user and kernel space.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/page.h | 2 +-
arch/powerpc/mm/ptdump/ptdump.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index a63fe6f3a0ff..352a2b80d505 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -256,7 +256,7 @@ static inline bool pfn_valid(unsigned long pfn)
#ifdef CONFIG_PPC_BOOK3E_64
#define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
#else
-#define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
+#define is_kernel_addr(x) ((x) >= TASK_SIZE)
#endif

#ifndef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index b71cc628facd..e995f2e9e9f7 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -351,7 +351,7 @@ static void populate_markers(void)
{
int i = 0;

- address_markers[i++].start_address = PAGE_OFFSET;
+ address_markers[i++].start_address = TASK_SIZE;
address_markers[i++].start_address = VMALLOC_START;
address_markers[i++].start_address = VMALLOC_END;
#ifdef CONFIG_PPC64
@@ -388,7 +388,7 @@ static int ptdump_show(struct seq_file *m, void *v)
struct pg_state st = {
.seq = m,
.marker = address_markers,
- .start_address = PAGE_OFFSET,
+ .start_address = TASK_SIZE,
};

#ifdef CONFIG_PPC64
@@ -432,7 +432,7 @@ void ptdump_check_wx(void)
.seq = NULL,
.marker = address_markers,
.check_wx = true,
- .start_address = PAGE_OFFSET,
+ .start_address = TASK_SIZE,
};

#ifdef CONFIG_PPC64
--
2.25.0