2019-05-24 06:08:55

by Christophe Leroy

Subject: [RFC PATCH v2] powerpc: fix kexec failure on book3s/32

Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Signed-off-by: Christophe Leroy <[email protected]>
---
arch/powerpc/kernel/machine_kexec_32.c | 8 ++++++++
arch/powerpc/mm/book3s32/mmu.c | 7 +++++--
arch/powerpc/mm/mmu_decl.h | 2 ++
3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/machine_kexec_32.c b/arch/powerpc/kernel/machine_kexec_32.c
index affe5dcce7f4..83e61a8f8468 100644
--- a/arch/powerpc/kernel/machine_kexec_32.c
+++ b/arch/powerpc/kernel/machine_kexec_32.c
@@ -15,6 +15,7 @@
#include <asm/cacheflush.h>
#include <asm/hw_irq.h>
#include <asm/io.h>
+#include <mm/mmu_decl.h>

typedef void (*relocate_new_kernel_t)(
unsigned long indirection_page,
@@ -35,6 +36,8 @@ void default_machine_kexec(struct kimage *image)
unsigned long page_list;
unsigned long reboot_code_buffer, reboot_code_buffer_phys;
relocate_new_kernel_t rnk;
+ unsigned long bat_size = 128 << 10;
+ unsigned long bat_mask = ~(bat_size - 1);

/* Interrupts aren't acceptable while we reboot */
local_irq_disable();
@@ -54,6 +57,11 @@ void default_machine_kexec(struct kimage *image)
memcpy((void *)reboot_code_buffer, relocate_new_kernel,
relocate_new_kernel_size);

+ printk(KERN_INFO "Reboot code buffer at %lx\n", reboot_code_buffer);
+ mtsrin(mfsrin(reboot_code_buffer) & ~SR_NX, reboot_code_buffer);
+ setibat(7, reboot_code_buffer & bat_mask, reboot_code_buffer_phys & bat_mask,
+ bat_size, PAGE_KERNEL_TEXT);
+
flush_icache_range(reboot_code_buffer,
reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
printk(KERN_INFO "Bye!\n");
diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
index fc073cb2c517..7124700edb0f 100644
--- a/arch/powerpc/mm/book3s32/mmu.c
+++ b/arch/powerpc/mm/book3s32/mmu.c
@@ -124,8 +124,8 @@ static unsigned int block_size(unsigned long base, unsigned long top)
* of 2 between 128k and 256M.
* Only for 603+ ...
*/
-static void setibat(int index, unsigned long virt, phys_addr_t phys,
- unsigned int size, pgprot_t prot)
+void setibat(int index, unsigned long virt, phys_addr_t phys,
+ unsigned int size, pgprot_t prot)
{
unsigned int bl = (size >> 17) - 1;
int wimgxpp;
@@ -197,6 +197,9 @@ void mmu_mark_initmem_nx(void)
if (cpu_has_feature(CPU_FTR_601))
return;

+ if (IS_ENABLED(CONFIG_KEXEC))
+ nb--;
+
for (i = 0; i < nb - 1 && base < top && top - base > (128 << 10);) {
size = block_size(base, top);
setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT);
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 7bac0aa2026a..478584d50cf2 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -103,6 +103,8 @@ void print_system_hash_info(void);
extern void mapin_ram(void);
extern void setbat(int index, unsigned long virt, phys_addr_t phys,
unsigned int size, pgprot_t prot);
+void setibat(int index, unsigned long virt, phys_addr_t phys,
+ unsigned int size, pgprot_t prot);

extern int __map_without_bats;
extern unsigned int rtas_data, rtas_size;
--
2.13.3

2019-05-24 13:42:02

by Christophe Leroy

Subject: Re: [RFC PATCH v2] powerpc: fix kexec failure on book3s/32

Le 24/05/2019 à 08:05, Christophe Leroy a écrit :
> Fixes: 63b2bc619565 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
> Signed-off-by: Christophe Leroy <[email protected]>

Reported-by: Aaro Koskinen <[email protected]>

> ---
> arch/powerpc/kernel/machine_kexec_32.c | 8 ++++++++
> arch/powerpc/mm/book3s32/mmu.c | 7 +++++--
> arch/powerpc/mm/mmu_decl.h | 2 ++
> 3 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kernel/machine_kexec_32.c b/arch/powerpc/kernel/machine_kexec_32.c
> index affe5dcce7f4..83e61a8f8468 100644
> --- a/arch/powerpc/kernel/machine_kexec_32.c
> +++ b/arch/powerpc/kernel/machine_kexec_32.c
> @@ -15,6 +15,7 @@
> #include <asm/cacheflush.h>
> #include <asm/hw_irq.h>
> #include <asm/io.h>
> +#include <mm/mmu_decl.h>
>
> typedef void (*relocate_new_kernel_t)(
> unsigned long indirection_page,
> @@ -35,6 +36,8 @@ void default_machine_kexec(struct kimage *image)
> unsigned long page_list;
> unsigned long reboot_code_buffer, reboot_code_buffer_phys;
> relocate_new_kernel_t rnk;
> + unsigned long bat_size = 128 << 10;
> + unsigned long bat_mask = ~(bat_size - 1);
>
> /* Interrupts aren't acceptable while we reboot */
> local_irq_disable();
> @@ -54,6 +57,11 @@ void default_machine_kexec(struct kimage *image)
> memcpy((void *)reboot_code_buffer, relocate_new_kernel,
> relocate_new_kernel_size);
>
> + printk(KERN_INFO "Reboot code buffer at %lx\n", reboot_code_buffer);
> + mtsrin(mfsrin(reboot_code_buffer) & ~SR_NX, reboot_code_buffer);
> + setibat(7, reboot_code_buffer & bat_mask, reboot_code_buffer_phys & bat_mask,
> + bat_size, PAGE_KERNEL_TEXT);

A call to update_bats() have to be added here after setibat()

Christophe

> +
> flush_icache_range(reboot_code_buffer,
> reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
> printk(KERN_INFO "Bye!\n");
> diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c
> index fc073cb2c517..7124700edb0f 100644
> --- a/arch/powerpc/mm/book3s32/mmu.c
> +++ b/arch/powerpc/mm/book3s32/mmu.c
> @@ -124,8 +124,8 @@ static unsigned int block_size(unsigned long base, unsigned long top)
> * of 2 between 128k and 256M.
> * Only for 603+ ...
> */
> -static void setibat(int index, unsigned long virt, phys_addr_t phys,
> - unsigned int size, pgprot_t prot)
> +void setibat(int index, unsigned long virt, phys_addr_t phys,
> + unsigned int size, pgprot_t prot)
> {
> unsigned int bl = (size >> 17) - 1;
> int wimgxpp;
> @@ -197,6 +197,9 @@ void mmu_mark_initmem_nx(void)
> if (cpu_has_feature(CPU_FTR_601))
> return;
>
> + if (IS_ENABLED(CONFIG_KEXEC))
> + nb--;
> +
> for (i = 0; i < nb - 1 && base < top && top - base > (128 << 10);) {
> size = block_size(base, top);
> setibat(i++, PAGE_OFFSET + base, base, size, PAGE_KERNEL_TEXT);
> diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
> index 7bac0aa2026a..478584d50cf2 100644
> --- a/arch/powerpc/mm/mmu_decl.h
> +++ b/arch/powerpc/mm/mmu_decl.h
> @@ -103,6 +103,8 @@ void print_system_hash_info(void);
> extern void mapin_ram(void);
> extern void setbat(int index, unsigned long virt, phys_addr_t phys,
> unsigned int size, pgprot_t prot);
> +void setibat(int index, unsigned long virt, phys_addr_t phys,
> + unsigned int size, pgprot_t prot);
>
> extern int __map_without_bats;
> extern unsigned int rtas_data, rtas_size;
>