Dt reserve memory without base checking, which will trigger an oops in
kmemleak when the base address is below MIN_MEMBLOCK_ADDR:
# echo scan > /sys/kernel/debug/kmemleak
[ 54.888353] Unable to handle kernel paging request at virtual address ff5fffffffe00000
[ 54.888932] Oops [#1]
[ 54.889102] Modules linked in:
[ 54.889326] CPU: 2 PID: 134 Comm: bash Not tainted 5.18.0-rc1-next-20220407 #33
[ 54.889620] Hardware name: riscv-virtio,qemu (DT)
[ 54.889901] epc : scan_block+0x74/0x15c
[ 54.890215] ra : scan_block+0x72/0x15c
[ 54.890390] epc : ffffffff801e5806 ra : ffffffff801e5804 sp : ff200000104abc30
[ 54.890607] gp : ffffffff815cd4e8 tp : ff60000004cfa340 t0 : 0000000000000200
[ 54.890835] t1 : 00aaaaaac23954cc t2 : 00000000000003ff s0 : ff200000104abc90
[ 54.891024] s1 : ffffffff81b0ff28 a0 : 0000000000000000 a1 : ff5fffffffe01000
[ 54.891201] a2 : ffffffff81b0ff28 a3 : 0000000000000002 a4 : 0000000000000001
[ 54.891377] a5 : 0000000000000000 a6 : ff200000104abd7c a7 : 0000000000000005
[ 54.891552] s2 : ff5fffffffe00ff9 s3 : ffffffff815cd998 s4 : ffffffff815d0e90
[ 54.891727] s5 : ffffffff81b0ff28 s6 : 0000000000000020 s7 : ffffffff815d0eb0
[ 54.891903] s8 : ffffffffffffffff s9 : ff5fffffffe00000 s10: ff5fffffffe01000
[ 54.892078] s11: 0000000000000022 t3 : 00ffffffaa17db4c t4 : 000000000000000f
[ 54.892271] t5 : 0000000000000001 t6 : 0000000000000000
[ 54.892408] status: 0000000000000100 badaddr: ff5fffffffe00000 cause: 000000000000000d
[ 54.892643] [<ffffffff801e5a1c>] scan_gray_list+0x12e/0x1a6
[ 54.892824] [<ffffffff801e5d3e>] kmemleak_scan+0x2aa/0x57e
[ 54.892961] [<ffffffff801e633c>] kmemleak_write+0x32a/0x40c
[ 54.893096] [<ffffffff803915ac>] full_proxy_write+0x56/0x82
[ 54.893235] [<ffffffff801ef456>] vfs_write+0xa6/0x2a6
[ 54.893362] [<ffffffff801ef880>] ksys_write+0x6c/0xe2
[ 54.893487] [<ffffffff801ef918>] sys_write+0x22/0x2a
[ 54.893609] [<ffffffff8000397c>] ret_from_syscall+0x0/0x2
[ 54.894183] ---[ end trace 0000000000000000 ]---
Add base checking and ignore the range lower than MIN_MEMBLOCK_ADDR.
Signed-off-by: Patrick Wang <patrick.wang.shcn@xxxxxxxxx>
---
drivers/of/fdt.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index ec315b060..296c4ab8e 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -33,6 +33,13 @@
#include "of_private.h"
+#ifndef MIN_MEMBLOCK_ADDR
+#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
+#endif
+#ifndef MAX_MEMBLOCK_ADDR
+#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
+#endif
+
/*
* of_fdt_limit_memory - limit the number of regions in the /memory node
* @limit: maximum entries
@@ -480,6 +487,19 @@ static u32 of_fdt_crc32;
static int __init early_init_dt_reserve_memory_arch(phys_addr_t base,
phys_addr_t size, bool nomap)
{
+ const u64 phys_offset = MIN_MEMBLOCK_ADDR;
+
+ if (base < phys_offset) {
+ pr_warn("Ignoring reserved memory range 0x%llx - 0x%llx\n",
+ base, phys_offset);
+ size = (phys_offset - base) < size ?
+ size - (phys_offset - base) : 0;
+ base = phys_offset;
+
+ if (!size)
+ return -EFAULT;
+ }
+
if (nomap) {
/*
* If the memory is already reserved (by another region), we
@@ -1198,13 +1218,6 @@ int __init early_init_dt_scan_chosen(char *cmdline)
return 0;
}
-#ifndef MIN_MEMBLOCK_ADDR
-#define MIN_MEMBLOCK_ADDR __pa(PAGE_OFFSET)
-#endif
-#ifndef MAX_MEMBLOCK_ADDR
-#define MAX_MEMBLOCK_ADDR ((phys_addr_t)~0)
-#endif
-
void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size)
{
const u64 phys_offset = MIN_MEMBLOCK_ADDR;
--
2.25.1
