Messages in this thread | | | From | Yu Chen <> | Subject | Re: [PATCH] arm: export memblock_reserve()d regions via /proc/iomem | Date | Mon, 23 Sep 2019 23:42:54 +0800 |
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From: Yu Chen <yu.chen3@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.chen3@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 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
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