This is a backport for 5.16 and 5.15.
To apply, it also requires commit 37eb7ca91b69 ("powerpc/32s: Allocate
one 256k IBAT instead of two consecutives 128k IBATs")
(cherry picked from commit d37823c3528e5e0705fc7746bcbc2afffb619259)
It has been reported some configuration where the kernel doesn't
boot with KASAN enabled.
This is due to wrong BAT allocation for the KASAN area:
---[ Data Block Address Translation ]---
0: 0xc000-0xcfff 0x 256M Kernel rw m
1: 0xd000-0xdfff 0x1000 256M Kernel rw m
2: 0xe000-0xefff 0x2000 256M Kernel rw m
3: 0xf800-0xf9ff 0x2a0032M Kernel rw m
4: 0xfa00-0xfdff 0x2c0064M Kernel rw m
A BAT must have both virtual and physical addresses alignment matching
the size of the BAT. This is not the case for BAT 4 above.
Fix kasan_init_region() by using block_size() function that is in
book3s32/mmu.c. To be able to reuse it here, make it non static and
change its name to bat_block_size() in order to avoid name conflict
with block_size() defined in
Also reuse find_free_bat() to avoid an error message from setbat()
when no BAT is available.
And allocate memory outside of linear memory mapping to avoid
wasting that precious space.
With this change we get correct alignment for BATs and KASAN shadow
memory is allocated outside the linear memory space.
---[ Data Block Address Translation ]---
0: 0xc000-0xcfff 0x 256M Kernel rw
1: 0xd000-0xdfff 0x1000 256M Kernel rw
2: 0xe000-0xefff 0x2000 256M Kernel rw
3: 0xf800-0xfbff 0x7c0064M Kernel rw
4: 0xfc00-0xfdff 0x7a0032M Kernel rw
Fixes: 7974c4732642 ("powerpc/32s: Implement dedicated kasan_init_region()")
Cc: sta...@vger.kernel.org
Reported-by: Maxime Bizon
Signed-off-by: Christophe Leroy
Tested-by: Maxime Bizon
Signed-off-by: Michael Ellerman
Link:
https://lore.kernel.org/r/7a50ef902494d1325227d47d33dada01e52e5518.1641818726.git.christophe.le...@csgroup.eu
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 2 +
arch/powerpc/mm/book3s32/mmu.c| 10 ++--
arch/powerpc/mm/kasan/book3s_32.c | 59 ++-
3 files changed, 38 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index f5be185cbdf8..94ad7acfd056 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -143,6 +143,8 @@ static __always_inline void update_user_segments(u32 val)
update_user_segment(15, val);
}
+int __init find_free_bat(void);
+unsigned int bat_block_size(unsigned long base, unsigned long top);
#endif /* !__ASSEMBLY__ */
/* We happily ignore the smaller BATs on 601, we don't actually use
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index 33ab63d56435..203735caf691 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -76,7 +76,7 @@ unsigned long p_block_mapped(phys_addr_t pa)
return 0;
}
-static int find_free_bat(void)
+int __init find_free_bat(void)
{
int b;
int n = mmu_has_feature(MMU_FTR_USE_HIGH_BATS) ? 8 : 4;
@@ -100,7 +100,7 @@ static int find_free_bat(void)
* - block size has to be a power of two. This is calculated by finding the
* highest bit set to 1.
*/
-static unsigned int block_size(unsigned long base, unsigned long top)
+unsigned int bat_block_size(unsigned long base, unsigned long top)
{
unsigned int max_size = SZ_256M;
unsigned int base_shift = (ffs(base) - 1) & 31;
@@ -145,7 +145,7 @@ static unsigned long __init __mmu_mapin_ram(unsigned long
base, unsigned long to
int idx;
while ((idx = find_free_bat()) != -1 && base != top) {
- unsigned int size = block_size(base, top);
+ unsigned int size = bat_block_size(base, top);
if (size < 128 << 10)
break;
@@ -201,12 +201,12 @@ void mmu_mark_initmem_nx(void)
unsigned long size;
for (i = 0; i < nb - 1 && base < top;) {
- size = block_size(base, top);
+ size = bat_block_size(base, top);
setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT);
base += size;
}
if (base < top) {
- size = block_size(base, top);
+ size = bat_block_size(base, top);
if ((top - base) > size) {
size <<= 1;
if (strict_kernel_rwx_enabled() && base + size > border)
diff --git a/arch/powerpc/mm/kasan/book3s_32.c
b/arch/powerpc/mm/kasan/book3s_32.c
index 35b287b0a8da..450a67ef0bbe 100644
--- a/arch/powerpc/mm/kasan/book3s_32.c
+++
