On Mon, Sep 23, 2019 at 11:42:54PM +0800, Yu Chen wrote: > From: Yu Chen <yu.ch...@zte.com.cn> > > On Sat, 21 Sep 2019 15:51:38, Russell King - ARM Linux admin wrote: > > On Sat, Sep 21, 2019 at 09:02:49PM +0800, Yu Chen wrote: > > > From: Yu Chen <yu.ch...@zte.com.cn> > > > > > > memblock reserved regions are not reported via /proc/iomem on ARM, kexec's > > > user-space doesn't know about memblock_reserve()d regions and thus > > > possible for kexec to overwrite with the new kernel or initrd. > > > > Many reserved regions come from the kernel allocating memory during > > boot. We don't want to prevent kexec re-using those regions. > > > > > [ 0.000000] Booting Linux on physical CPU 0xf00 > > > [ 0.000000] Linux version 4.9.115-rt93-dirty > > > (yuchen@localhost.localdomain) (gcc version 6.2.0 (ZTE Embsys-TSP V3.07.2 > > > 0) ) #62 SMP PREEMPT Fri Sep 20 10:39:29 CST 2019 > > > [ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), > > > cr=30c5387d > > > [ 0.000000] CPU: div instructions available: patching division code > > > [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing > > > instruction cache > > > [ 0.000000] OF: fdt:Machine model: LS1021A TWR Board > > > [ 0.000000] INITRD: 0x80f7f000+0x03695e40 overlaps in-use memory > > > region - disabling initrd > > > > Is the overlapping region one that is marked as reserved in DT? > > the overlapping region is not reserved in DT. > > > Where is the reserved region that overlaps the initrd coming from? > > I found the reserved region that overlaps the initrd is kernel code & data, > with memblock=debug cmdline start new kerne: > > / # kexec -l uImage-ls1021a --ramdisk=ramdisk-ls1021a --dtb=fdt > --append="root=/ > dev/ram0 rw console=ttyS0,115200 earlyprintk memblock=debug" -d > Try gzip decompression. > Try LZMA decompression. > lzma_decompress_file: read on uImage-ls1021a of 65536 bytes failed > kernel: 0xb6c71008 kernel_size: 0x317ab8 > MEMORY RANGES > 0000000080000000-00000000bfffffff (0) > 0000000080003000-0000000080007fff (1) > 0000000080e00000-0000000080ffffff (1) > 00000000810c45a4-00000000810c4fff (1) > 0000000081ac4000-0000000085159fff (1) > 000000008515a000-000000008515ffff (1) > 0000000088000000-000000008b695fff (1) > 000000008f000000-000000008f004fff (1) > 00000000af709000-00000000af7eafff (1) > 00000000af7ed000-00000000afffbfff (1) > 00000000afffc000-00000000afffcfff (1) > 00000000afffd000-00000000afffffff (1) > 00000000bc000000-00000000bfffffff (1) > zImage header: 0x016f2818 0x00000000 0x00317a78 > zImage size 0x317a78, file size 0x317a78
I see nothing here that suggests either a new kexec or a sufficiently new kernel. Hence, kexec lacks all the information to correctly layout the images in physical memory. The kernel was augmented with additional information around the v4.15 time. See commits: c772568788b5 ARM: add additional table to compressed kernel 429f7a062e3b ARM: decompressor: fix BSS size calculation 99cf8f903148 ARM: better diagnostics with missing/corrupt dtb There may be some others also needed, but I forget now, it was two years ago. For kexec, you need at least 2.0.17 (2.0.16 merged the wrong version of one of my patches.) > kexec_load: entry = 0x80008000 flags = 0x280000 > nr_segments = 3 > segment[0].buf = 0xb6c71048 > segment[0].bufsz = 0x317a78 > segment[0].mem = 0x80008000 > segment[0].memsz = 0x318000 > segment[1].buf = 0xb35db048 > segment[1].bufsz = 0x3695e40 > segment[1].mem = 0x80f7f000 > segment[1].memsz = 0x3696000 > segment[2].buf = 0x100b108 > segment[2].bufsz = 0x5090 > segment[2].mem = 0x84615000 > segment[2].memsz = 0x6000 > / # kexec -e > [ 126.583598] kexec_core: Starting new kernel > [ 126.587815] Disabling non-boot CPUs ... > [ 126.626917] CPU1: shutdown > [ 126.656344] Retrying again to check for CPU kill > [ 126.660947] CPU1 killed. > [ 126.687585] Bye! > [ 0.000000] Booting Linux on physical CPU 0xf00 > [ 0.000000] Linux version 4.9.115-rt93-CGEL-V6.02.10.R4-dirty > (yuchen@localhost.localdomain) (gcc version 6.2.0 (ZTE Embsys-TSP V3.07.20) ) > #62 SMP PREEMPT Fri Sep 20 10:39:29 CST 2019 > [ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=30c5387d > [ 0.000000] CPU: div instructions available: patching division code > [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing > instruction cache > [ 0.000000] OF: fdt:Machine model: LS1021A TWR Board > [ 0.000000] memblock_reserve: [0x00000080200000-0x000000810c45a3] flags > 0x0 arm_memblock_init+0x44/0x23c > [ 0.000000] INITRD: 0x80f7f000+0x03695e40 overlaps in-use memory region - > disabling initrd > [ 0.000000] memblock_reserve: [0x00000080003000-0x00000080007fff] flags > 0x0 arm_mm_memblock_reserve+0x2c/0x30 > [ 0.000000] memblock_reserve: [0x00000084615000-0x0000008461a08f] flags > 0x0 early_init_dt_reserve_memory_arch+0x24/0x28 > [ 0.000000] memblock_reserve: [0x0000008f000000-0x0000008f004fff] flags > 0x0 early_init_dt_reserve_memory_arch+0x24/0x28 > [ 0.000000] memblock_reserve: [0x00000088000040-0x0000008b695e3f] flags > 0x0 early_init_dt_reserve_memory_arch+0x24/0x28 > [ 0.000000] memblock_reserve: [0x000000bc000000-0x000000bfffffff] flags > 0x0 memblock_alloc_range_nid+0x78/0x90 > ... > ---[ end Kernel panic - not syncing: VFS: Unable to mount root fs on > unknown-block(1,0) > > this overlay region is [0x00000080200000-0x000000810c45a3] > > Corresponding kernel source code: > 264 void __init arm_memblock_init(const struct machine_desc *mdesc) > 265 { > 266 /* Register the kernel text, kernel data and initrd with > memblock. */ > 267 memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START); > > > > > Thanks. > > > > -- > > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > > FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps > > up > > According to speedtest.net: 11.9Mbps down 500kbps up > > And Sorry, I sent the wrong arm64 patch. if possible, I will resend the > second version of the patch. > > Yu Chen > > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up