From 85f58eb1889826b9745737718723a80b639e0fbd Mon Sep 17 00:00:00 2001 From: Chen Wandun Date: Fri, 10 Sep 2021 14:48:44 +0800 Subject: [PATCH] arm64: kdump: Skip kmemleak scan reserved memory for kdump Trying to boot with kdump + kmemleak, command will result in a crash: "echo scan > /sys/kernel/debug/kmemleak" crashkernel reserved: 0x0000000007c00000 - 0x0000000027c00000 (512 MB) Kernel command line: BOOT_IMAGE=(hd1,gpt2)/vmlinuz-5.14.0-rc5-next-20210809+ root=/dev/mapper/ao-root ro rd.lvm.lv=ao/root rd.lvm.lv=ao/swap crashkernel=512M Unable to handle kernel paging request at virtual address ffff000007c00000 Mem abort info: ESR = 0x96000007 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000007 CM = 0, WnR = 0 swapper pgtable: 64k pages, 48-bit VAs, pgdp=00002024f0d80000 [ffff000007c00000] pgd=1800205ffffd0003, p4d=1800205ffffd0003, pud=1800205ffffd0003, pmd=1800205ffffc0003, pte=0068000007c00f06 Internal error: Oops: 96000007 [#1] SMP pstate: 804000c9 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : scan_block+0x98/0x230 lr : scan_block+0x94/0x230 sp : ffff80008d6cfb70 x29: ffff80008d6cfb70 x28: 0000000000000000 x27: 0000000000000000 x26: 00000000000000c0 x25: 0000000000000001 x24: 0000000000000000 x23: ffffa88a6b18b398 x22: ffff000007c00ff9 x21: ffffa88a6ac7fc40 x20: ffffa88a6af6a830 x19: ffff000007c00000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: ffffffffffffffff x14: ffffffff00000000 x13: ffffffffffffffff x12: 0000000000000020 x11: 0000000000000000 x10: 0000000001080000 x9 : ffffa88a6951c77c x8 : ffffa88a6a893988 x7 : ffff203ff6cfb3c0 x6 : ffffa88a6a52b3c0 x5 : ffff203ff6cfb3c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000001 x1 : ffff20226cb56a40 x0 : 0000000000000000 Call trace: scan_block+0x98/0x230 scan_gray_list+0x120/0x270 kmemleak_scan+0x3a0/0x648 kmemleak_write+0x3ac/0x4c8 full_proxy_write+0x6c/0xa0 vfs_write+0xc8/0x2b8 ksys_write+0x70/0xf8 __arm64_sys_write+0x24/0x30 invoke_syscall+0x4c/0x110 el0_svc_common+0x9c/0x190 do_el0_svc+0x30/0x98 el0_svc+0x28/0xd8 el0t_64_sync_handler+0x90/0xb8 el0t_64_sync+0x180/0x184 The reserved memory for kdump will be looked up by kmemleak, this area will be set invalid when kdump service is bring up. That will result in crash when kmemleak scan this area. Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private") Signed-off-by: Chen Wandun Reviewed-by: Kefeng Wang Reviewed-by: Mike Rapoport Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20210910064844.3827813-1-chenwandun@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/mm/init.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 2b28d77e29a0..5a16f5715716 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include @@ -115,6 +116,11 @@ static void __init reserve_crashkernel(void) pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n", crash_base, crash_base + crash_size, crash_size >> 20); + /* + * The crashkernel memory will be removed from the kernel linear + * map. Inform kmemleak so that it won't try to access it. + */ + kmemleak_ignore_phys(crash_base); crashk_res.start = crash_base; crashk_res.end = crash_base + crash_size - 1; } -- 2.20.1