[RFC/PATCH v3] arm64: define MODULES_VADDR by module_alloc_base

From: Miles Chen
Date: Wed Aug 30 2017 - 07:47:00 EST

Next message: Colin King: "[PATCH][next] bpf: test_maps: fix typo "conenct" -> "connext""
Previous message: Christoffer Dall: "Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

After the kernel ASLR, the module virtual address is moved to
[module_alloc_base, module_alloc_base + MODULES_VSIZE).
However, the MODULES_VADDR is still defined as a constant and functions
like is_vmalloc_or_module_addr() or dump functions will not able to
use correct module range information.

The patch omits modules information in virtual kenrel memory layout if
the modules area is fully mapped whitin vmalloc area.

Use module_alloc_base to define MODULES_VADDR. I tested the patch under
three different conditions:
1.CONFIG_RANDOMIZE_BASE=y, seed=0
CONFIG_KASAN=n
2.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333
CONFIG_KASAN=n
3.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333
CONFIG_KASAN=y

test log:

1.CONFIG_RANDOMIZE_BASE=y, seed=0
CONFIG_KASAN=n

[ 0.000000] Virtual kernel memory layout:
[ 0.000000] modules : 0xffffff8000550000 - 0xffffff8008550000 ( 128 MB)
[ 0.000000] vmalloc : 0xffffff8008000000 - 0xffffffbebfff0000 ( 250 GB)
[ 0.000000] .text : 0xffffff8008080000 - 0xffffff8008550000 ( 4928 KB)
[ 0.000000] .rodata : 0xffffff8008550000 - 0xffffff80086a0000 ( 1344 KB)
[ 0.000000] .init : 0xffffff80086a0000 - 0xffffff8008a30000 ( 3648 KB)
[ 0.000000] .data : 0xffffff8008a30000 - 0xffffff8008ab9200 ( 549 KB)
[ 0.000000] .bss : 0xffffff8008ab9200 - 0xffffff8008b0b238 ( 329 KB)
[ 0.000000] fixed : 0xffffffbefe7fd000 - 0xffffffbefec00000 ( 4108 KB)
[ 0.000000] PCI I/O : 0xffffffbefee00000 - 0xffffffbeffe00000 ( 16 MB)
[ 0.000000] vmemmap : 0xffffffbf00000000 - 0xffffffc000000000 ( 4 GB maximum)
[ 0.000000] 0xffffffbf00000000 - 0xffffffbf02000000 ( 32 MB actual)
[ 0.000000] memory : 0xffffffc000000000 - 0xffffffc080000000 ( 2048 MB)

\# cat kernel_page_tables
---[ Modules start ]---
---[ Modules end ]---
---[ vmalloc() Area ]---
0xffffff8008000000-0xffffff8008010000 64K PTE RW NX SHD AF
0xffffff8008015000-0xffffff8008016000 4K PTE RW NX SHD AF
...

2.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333
CONFIG_KASAN=n

[ 0.000000] Virtual kernel memory layout:
[ 0.000000] vmalloc : 0xffffff8008000000 - 0xffffffbebfff0000 ( 250 GB)
[ 0.000000] .text : 0xffffff902b280000 - 0xffffff902b750000 ( 4928 KB)
[ 0.000000] .rodata : 0xffffff902b750000 - 0xffffff902b8a0000 ( 1344 KB)
[ 0.000000] .init : 0xffffff902b8a0000 - 0xffffff902bc30000 ( 3648 KB)
[ 0.000000] .data : 0xffffff902bc30000 - 0xffffff902bcb9200 ( 549 KB)
[ 0.000000] .bss : 0xffffff902bcb9200 - 0xffffff902bd0b238 ( 329 KB)
[ 0.000000] fixed : 0xffffffbefe7fd000 - 0xffffffbefec00000 ( 4108 KB)
[ 0.000000] PCI I/O : 0xffffffbefee00000 - 0xffffffbeffe00000 ( 16 MB)
[ 0.000000] vmemmap : 0xffffffbf00000000 - 0xffffffc000000000 ( 4 GB maximum)
[ 0.000000] 0xffffffbf22000000 - 0xffffffbf24000000 ( 32 MB actual)
[ 0.000000] memory : 0xffffffc880000000 - 0xffffffc900000000 ( 2048 MB)

\# cat kernel_page_tables
---[ vmalloc() Area ]---
0xffffff8008000000-0xffffff8008010000 64K PTE RW NX SHD AF
0xffffff8008015000-0xffffff8008016000 4K PTE RW NX SHD AF
0xffffff8008020000-0xffffff8008030000 64K PTE RW NX SHD AF
0xffffff8008031000-0xffffff8008071000 256K PTE RW NX SHD AF
0xffffff800813a000-0xffffff800813d000 12K PTE RW NX SHD AF
...

3.CONFIG_RANDOMIZE_BASE=y, seed=0x2304909023333333
CONFIG_KASAN=y

[ 0.000000] Virtual kernel memory layout:
[ 0.000000] kasan : 0xffffff8000000000 - 0xffffff9000000000 ( 64 GB)
[ 0.000000] modules : 0xffffff9000560000 - 0xffffff9008560000 ( 128 MB)
[ 0.000000] vmalloc : 0xffffff9008560000 - 0xffffffbebfff0000 ( 186 GB)
[ 0.000000] .text : 0xffffffa02b280000 - 0xffffffa02b760000 ( 4992 KB)
[ 0.000000] .rodata : 0xffffffa02b760000 - 0xffffffa02b8b0000 ( 1344 KB)
[ 0.000000] .init : 0xffffffa02b8b0000 - 0xffffffa02bc40000 ( 3648 KB)
[ 0.000000] .data : 0xffffffa02bc40000 - 0xffffffa02bcc9200 ( 549 KB)
[ 0.000000] .bss : 0xffffffa02bcc9200 - 0xffffffa02c5342b8 ( 8621 KB)
[ 0.000000] fixed : 0xffffffbefe7fd000 - 0xffffffbefec00000 ( 4108 KB)
[ 0.000000] PCI I/O : 0xffffffbefee00000 - 0xffffffbeffe00000 ( 16 MB)
[ 0.000000] vmemmap : 0xffffffbf00000000 - 0xffffffc000000000 ( 4 GB maximum)
[ 0.000000] 0xffffffbf22000000 - 0xffffffbf24000000 ( 32 MB actual)
[ 0.000000] memory : 0xffffffc880000000 - 0xffffffc900000000 ( 2048 MB)

\# cat kernel_page_tables
---[ Kasan shadow start ]---
0xffffff8000000000-0xffffff82000ac000 8389296K PTE ro NX SHD AF
0xffffff82010ac000-0xffffff8405600000 8459600K PTE ro NX SHD AF
0xffffff8405600000-0xffffff8405a00000 4M PMD RW NX SHD AF
0xffffff8405a00000-0xffffff8800000000 16294M PTE ro NX SHD AF
0xffffff8910000000-0xffffff8920000000 256M PMD RW NX SHD AF
---[ Kasan shadow end ]---
---[ Modules start ]---
---[ Modules end ]---
---[ vmalloc() Area ]---
0xffffff9008560000-0xffffff9008570000 64K PTE RW NX SHD AF
0xffffff9008575000-0xffffff9008576000 4K PTE RW NX SHD AF
0xffffff9008580000-0xffffff9008590000 64K PTE RW NX SHD AF
0xffffff9008591000-0xffffff90085d1000 256K PTE RW NX SHD AF
...

Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx>
---
arch/arm64/include/asm/memory.h | 12 +++++++--
arch/arm64/include/asm/module.h | 6 -----
arch/arm64/include/asm/pgtable.h | 4 +++
arch/arm64/mm/dump.c | 53 ++++++++++++++++++++++++++++++++++++----
arch/arm64/mm/init.c | 6 +++--
5 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index ef39dcb..41b885c 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -68,9 +68,11 @@
(UL(1) << VA_BITS) + 1)
#define PAGE_OFFSET (UL(0xffffffffffffffff) - \
(UL(1) << (VA_BITS - 1)) + 1)
-#define KIMAGE_VADDR (MODULES_END)
+#define KIMAGE_VADDR (STATIC_MODULES_END)
+#define STATIC_MODULES_END (STATIC_MODULES_VADDR + MODULES_VSIZE)
+#define STATIC_MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE)
#define MODULES_END (MODULES_VADDR + MODULES_VSIZE)
-#define MODULES_VADDR (VA_START + KASAN_SHADOW_SIZE)
+#define MODULES_VADDR ((unsigned long)module_alloc_base)
#define MODULES_VSIZE (SZ_128M)
#define VMEMMAP_START (PAGE_OFFSET - VMEMMAP_SIZE)
#define PCI_IO_END (VMEMMAP_START - SZ_2M)
@@ -138,6 +140,12 @@
#include <linux/bitops.h>
#include <linux/mmdebug.h>

+#ifdef CONFIG_RANDOMIZE_BASE
+extern u64 module_alloc_base;
+#else
+#define module_alloc_base ((u64)_etext - MODULES_VSIZE)
+#endif
+
extern s64 memstart_addr;
/* PHYS_OFFSET - the physical address of the start of memory. */
#define PHYS_OFFSET ({ VM_BUG_ON(memstart_addr & 1); memstart_addr; })
diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h
index 19bd976..fdf0db4 100644
--- a/arch/arm64/include/asm/module.h
+++ b/arch/arm64/include/asm/module.h
@@ -39,10 +39,4 @@ struct mod_arch_specific {
u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela,
Elf64_Sym *sym);

-#ifdef CONFIG_RANDOMIZE_BASE
-extern u64 module_alloc_base;
-#else
-#define module_alloc_base ((u64)_etext - MODULES_VSIZE)
-#endif
-
#endif /* __ASM_MODULE_H */
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 6eae342..6e309aa 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -30,7 +30,11 @@
* VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space
* and fixed mappings
*/
+#ifdef CONFIG_KASAN
#define VMALLOC_START (MODULES_END)
+#else
+#define VMALLOC_START (STATIC_MODULES_END)
+#endif
#define VMALLOC_END (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)

#define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index ca74a2a..18be771 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -29,15 +29,36 @@
#include <asm/pgtable-hwdef.h>
#include <asm/ptdump.h>

-static const struct addr_marker address_markers[] = {
+enum marker {
+#ifdef CONFIG_KASAN
+ E_KASAN_SHADOW_START,
+ E_KASAN_SHADOW_END,
+#endif
+ E_MODULES_VADDR,
+ E_MODULES_END,
+ E_VMALLOC_START,
+ E_VMALLOC_END,
+ E_FIXADDR_START,
+ E_FIXADDR_TOP,
+ E_PCI_IO_START,
+ E_PCI_IO_END,
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+ E_VMEMMAP_START,
+ E_VMEMMAP_END,
+#endif
+ E_PAGE_OFFSET,
+ E_NR_MARKER,
+};
+
+static struct addr_marker address_markers[] = {
#ifdef CONFIG_KASAN
{ KASAN_SHADOW_START, "Kasan shadow start" },
{ KASAN_SHADOW_END, "Kasan shadow end" },
#endif
- { MODULES_VADDR, "Modules start" },
- { MODULES_END, "Modules end" },
- { VMALLOC_START, "vmalloc() Area" },
- { VMALLOC_END, "vmalloc() End" },
+ { -1, "Modules start" },
+ { -1, "Modules end" },
+ { -1, "vmalloc() Area" },
+ { -1, "vmalloc() End" },
{ FIXADDR_START, "Fixmap start" },
{ FIXADDR_TOP, "Fixmap end" },
{ PCI_IO_START, "PCI I/O start" },
@@ -362,10 +383,32 @@ void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
note_page(&st, 0, 0, 0);
}

+static void fixup_markers(void)
+{
+ int i;
+
+ address_markers[E_MODULES_VADDR].start_address = MODULES_VADDR;
+ address_markers[E_MODULES_END].start_address = MODULES_END;
+ address_markers[E_VMALLOC_START].start_address = VMALLOC_START;
+ address_markers[E_VMALLOC_END].start_address = VMALLOC_END;
+
+ if (MODULES_VADDR < VMALLOC_START) {
+ address_markers[E_MODULES_END].start_address =
+ (MODULES_END < VMALLOC_START) ?
+ MODULES_END : VMALLOC_START;
+ } else {
+ /* modules is contains in vamlloc area, don't show them */
+ for (i = E_MODULES_VADDR; i <= E_NR_MARKER - 2; i++)
+ address_markers[i] = address_markers[i + 2];
+ }
+}
+
static void ptdump_initialize(void)
{
unsigned i, j;

+ fixup_markers();
+
for (i = 0; i < ARRAY_SIZE(pg_level); i++)
if (pg_level[i].bits)
for (j = 0; j < pg_level[i].num; j++)
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 5960bef..be77b26 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -609,8 +609,10 @@ void __init mem_init(void)
pr_notice(" kasan : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(KASAN_SHADOW_START, KASAN_SHADOW_END));
#endif
- pr_notice(" modules : 0x%16lx - 0x%16lx (%6ld MB)\n",
- MLM(MODULES_VADDR, MODULES_END));
+ /* print modules info when it's not fully mapped within vamlloc */
+ if (MODULES_VADDR < VMALLOC_START)
+ pr_notice(" modules : 0x%16lx - 0x%16lx (%6ld MB)\n",
+ MLM(MODULES_VADDR, MODULES_END));
pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(VMALLOC_START, VMALLOC_END));
pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
--
1.9.1

Next message: Colin King: "[PATCH][next] bpf: test_maps: fix typo "conenct" -> "connext""
Previous message: Christoffer Dall: "Re: [PATCH v3 41/59] KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]