* [PATCH v3 1/4] kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping
2023-05-12 1:57 [PATCH v3 0/4] LoongArch: Add kernel address sanitizer support Qing Zhang
@ 2023-05-12 1:57 ` Qing Zhang
2023-05-12 1:57 ` [PATCH v3 2/4] kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate process Qing Zhang
2023-05-12 1:57 ` [PATCH v3 3/4] LoongArch: Simplify the processing of jumping new kernel for KASLR Qing Zhang
2 siblings, 0 replies; 4+ messages in thread
From: Qing Zhang @ 2023-05-12 1:57 UTC (permalink / raw)
To: Andrey Ryabinin, Jonathan Corbet, Huacai Chen, Andrew Morton
Cc: Alexander Potapenko, Andrey Konovalov, Dmitry Vyukov,
Vincenzo Frascino, WANG Xuerui, Jiaxun Yang, kasan-dev,
linux-doc, linux-mm, loongarch, linux-kernel, linux-hardening
MIPS, LoongArch and some other architectures have many holes between
different segments and the valid address space (256T available) is
insufficient to map all these segments to kasan shadow memory with the
common formula provided by kasan core. So we need architecture specific
mapping formulas to ensure different segments are mapped individually,
and only limited space lengths of those specific segments are mapped to
shadow.
Therefore, when the incoming address is converted to a shadow, we need
to add a condition to determine whether it is valid.
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
---
include/linux/kasan.h | 2 ++
mm/kasan/kasan.h | 6 ++++++
2 files changed, 8 insertions(+)
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index f7ef70661ce2..3b91b941873d 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -54,11 +54,13 @@ extern p4d_t kasan_early_shadow_p4d[MAX_PTRS_PER_P4D];
int kasan_populate_early_shadow(const void *shadow_start,
const void *shadow_end);
+#ifndef __HAVE_ARCH_SHADOW_MAP
static inline void *kasan_mem_to_shadow(const void *addr)
{
return (void *)((unsigned long)addr >> KASAN_SHADOW_SCALE_SHIFT)
+ KASAN_SHADOW_OFFSET;
}
+#endif
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index a61eeee3095a..033335c13b25 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -291,16 +291,22 @@ struct kasan_stack_ring {
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+#ifndef __HAVE_ARCH_SHADOW_MAP
static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
<< KASAN_SHADOW_SCALE_SHIFT);
}
+#endif
static __always_inline bool addr_has_metadata(const void *addr)
{
+#ifdef __HAVE_ARCH_SHADOW_MAP
+ return (kasan_mem_to_shadow((void *)addr) != NULL);
+#else
return (kasan_reset_tag(addr) >=
kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
+#endif
}
/**
--
2.36.0
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v3 2/4] kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate process
2023-05-12 1:57 [PATCH v3 0/4] LoongArch: Add kernel address sanitizer support Qing Zhang
2023-05-12 1:57 ` [PATCH v3 1/4] kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping Qing Zhang
@ 2023-05-12 1:57 ` Qing Zhang
2023-05-12 1:57 ` [PATCH v3 3/4] LoongArch: Simplify the processing of jumping new kernel for KASLR Qing Zhang
2 siblings, 0 replies; 4+ messages in thread
From: Qing Zhang @ 2023-05-12 1:57 UTC (permalink / raw)
To: Andrey Ryabinin, Jonathan Corbet, Huacai Chen, Andrew Morton
Cc: Alexander Potapenko, Andrey Konovalov, Dmitry Vyukov,
Vincenzo Frascino, WANG Xuerui, Jiaxun Yang, kasan-dev,
linux-doc, linux-mm, loongarch, linux-kernel, linux-hardening
LoongArch populates pmd/pud with invalid_pmd_table/invalid_pud_table in
pagetable_init, So pmd_init/pud_init(p) is required, define them as __weak
in mm/kasan/init.c, like mm/sparse-vmemmap.c.
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
---
mm/kasan/init.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/mm/kasan/init.c b/mm/kasan/init.c
index cc64ed6858c6..a7fa223b96e4 100644
--- a/mm/kasan/init.c
+++ b/mm/kasan/init.c
@@ -139,6 +139,10 @@ static int __ref zero_pmd_populate(pud_t *pud, unsigned long addr,
return 0;
}
+void __weak __meminit pmd_init(void *addr)
+{
+}
+
static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
unsigned long end)
{
@@ -166,8 +170,9 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
if (!p)
return -ENOMEM;
} else {
- pud_populate(&init_mm, pud,
- early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pmd_init(p);
+ pud_populate(&init_mm, pud, p);
}
}
zero_pmd_populate(pud, addr, next);
@@ -176,6 +181,10 @@ static int __ref zero_pud_populate(p4d_t *p4d, unsigned long addr,
return 0;
}
+void __weak __meminit pud_init(void *addr)
+{
+}
+
static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
unsigned long end)
{
@@ -207,8 +216,9 @@ static int __ref zero_p4d_populate(pgd_t *pgd, unsigned long addr,
if (!p)
return -ENOMEM;
} else {
- p4d_populate(&init_mm, p4d,
- early_alloc(PAGE_SIZE, NUMA_NO_NODE));
+ p = early_alloc(PAGE_SIZE, NUMA_NO_NODE);
+ pud_init(p);
+ p4d_populate(&init_mm, p4d, p);
}
}
zero_pud_populate(p4d, addr, next);
--
2.36.0
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v3 3/4] LoongArch: Simplify the processing of jumping new kernel for KASLR
2023-05-12 1:57 [PATCH v3 0/4] LoongArch: Add kernel address sanitizer support Qing Zhang
2023-05-12 1:57 ` [PATCH v3 1/4] kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mapping Qing Zhang
2023-05-12 1:57 ` [PATCH v3 2/4] kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate process Qing Zhang
@ 2023-05-12 1:57 ` Qing Zhang
2 siblings, 0 replies; 4+ messages in thread
From: Qing Zhang @ 2023-05-12 1:57 UTC (permalink / raw)
To: Andrey Ryabinin, Jonathan Corbet, Huacai Chen, Andrew Morton
Cc: Alexander Potapenko, Andrey Konovalov, Dmitry Vyukov,
Vincenzo Frascino, WANG Xuerui, Jiaxun Yang, kasan-dev,
linux-doc, linux-mm, loongarch, linux-kernel, linux-hardening
Modified relocate_kernel() doesn't return new kernel's entry point but
the random_offset. In this way we share the start_kernel() processing
with the normal kernel, which avoids calling 'jr a0' directly and allows
some other operations (e.g, kasan_early_init) before start_kernel() when
KASLR (CONFIG_RANDOMIZE_BASE) is turned on.
Signed-off-by: Qing Zhang <zhangqing@loongson.cn>
---
arch/loongarch/include/asm/setup.h | 2 +-
arch/loongarch/kernel/head.S | 11 ++++++-----
arch/loongarch/kernel/relocate.c | 8 ++------
3 files changed, 9 insertions(+), 12 deletions(-)
diff --git a/arch/loongarch/include/asm/setup.h b/arch/loongarch/include/asm/setup.h
index be05c0e706a2..2dca0d1dd90a 100644
--- a/arch/loongarch/include/asm/setup.h
+++ b/arch/loongarch/include/asm/setup.h
@@ -33,7 +33,7 @@ extern long __la_abs_end;
extern long __rela_dyn_begin;
extern long __rela_dyn_end;
-extern void * __init relocate_kernel(void);
+extern unsigned long __init relocate_kernel(void);
#endif
diff --git a/arch/loongarch/kernel/head.S b/arch/loongarch/kernel/head.S
index aa64b179744f..aace7a300cd3 100644
--- a/arch/loongarch/kernel/head.S
+++ b/arch/loongarch/kernel/head.S
@@ -95,13 +95,14 @@ SYM_CODE_START(kernel_entry) # kernel entry point
PTR_LI sp, (_THREAD_SIZE - PT_SIZE)
PTR_ADD sp, sp, tp
set_saved_sp sp, t0, t1
-#endif
- /* relocate_kernel() returns the new kernel entry point */
- jr a0
- ASM_BUG()
+ /* Jump to the new kernel: new_pc = current_pc + random_offset */
+ pcaddi t0, 0
+ add.d t0, t0, a0
+ jirl zero, t0, 0xc
+#endif /* CONFIG_RANDOMIZE_BASE */
-#endif
+#endif /* CONFIG_RELOCATABLE */
bl start_kernel
ASM_BUG()
diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c
index 01f94d1e3edf..6c3eff9af9fb 100644
--- a/arch/loongarch/kernel/relocate.c
+++ b/arch/loongarch/kernel/relocate.c
@@ -157,12 +157,11 @@ static inline void __init update_reloc_offset(unsigned long *addr, long random_o
*new_addr = (unsigned long)reloc_offset;
}
-void * __init relocate_kernel(void)
+unsigned long __init relocate_kernel(void)
{
unsigned long kernel_length;
unsigned long random_offset = 0;
void *location_new = _text; /* Default to original kernel start */
- void *kernel_entry = start_kernel; /* Default to original kernel entry point */
char *cmdline = early_ioremap(fw_arg1, COMMAND_LINE_SIZE); /* Boot command line is passed in fw_arg1 */
strscpy(boot_command_line, cmdline, COMMAND_LINE_SIZE);
@@ -190,9 +189,6 @@ void * __init relocate_kernel(void)
reloc_offset += random_offset;
- /* Return the new kernel's entry point */
- kernel_entry = RELOCATED_KASLR(start_kernel);
-
/* The current thread is now within the relocated kernel */
__current_thread_info = RELOCATED_KASLR(__current_thread_info);
@@ -204,7 +200,7 @@ void * __init relocate_kernel(void)
relocate_absolute(random_offset);
- return kernel_entry;
+ return random_offset;
}
/*
--
2.36.0
^ permalink raw reply [flat|nested] 4+ messages in thread