Re: [PATCH v5 0/6] implement KASLR for powerpc/fsl_booke/64

From: Jason Yan
Date: Sat Apr 25 2020 - 23:56:22 EST

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Hi Daniel,

Thanks for the test. Can you send me the full log which may contain the system info such as the following:

-----------------------------------------------------
phys_mem_size = 0x200000000
dcache_bsize = 0x20
icache_bsize = 0x20
cpu_features = 0x00000003008003b6
possible = 0x00000003009003b6
always = 0x00000003008003b4
cpu_user_features = 0xdc008000 0x08000000
mmu_features = 0x000a0010
firmware_features = 0x0000000000000000
physical_start = 0x20000000
-----------------------------------------------------
barrier-nospec: using isync; sync as speculation barrier
Zone ranges:
DMA [mem 0x0000000000000000-0x000000007fffffff]
Normal [mem 0x0000000080000000-0x00000001ffffffff]
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000000000000-0x00000001ffffffff]
Initmem setup node 0 [mem 0x0000000000000000-0x00000001ffffffff]
MMU: Allocated 2112 bytes of context maps for 255 contexts
percpu: Embedded 32 pages/cpu s91736 r0 d39336 u131072
Built 1 zonelists, mobility grouping on. Total pages: 2064384
Kernel command line: console=ttyS0 root=/dev/ram0
printk: log_buf_len individual max cpu contribution: 16384 bytes
printk: log_buf_len total cpu_extra contributions: 376832 bytes
printk: log_buf_len min size: 131072 bytes
printk: log_buf_len: 524288 bytes
printk: early log buf free: 127460(97%)
Dentry cache hash table entries: 1048576 (order: 11, 8388608 bytes, linear)
Inode-cache hash table entries: 524288 (order: 10, 4194304 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Memory: 8135632K/8388608K available (10572K kernel code, 2000K rwdata, 3396K rodata, 4124K init, 358K bss, 252976K reserved, 0K cma-reserved)
rcu: Hierarchical RCU implementation.
rcu: RCU event tracing is enabled.
rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
NR_IRQS: 512, nr_irqs: 512, preallocated irqs: 16
mpic: Setting up MPIC " OpenPIC " version 1.2 at fe0040000, max 24 CPUs
mpic: ISU size: 256, shift: 8, mask: ff
mpic: Initializing for 256 sources
random: get_random_u64 called from .start_kernel+0x724/0x954 with crng_init=0
clocksource: timebase: mask: 0xffffffffffffffff max_cycles: 0x5c4093a7d1, max_idle_ns: 440795210635 ns
clocksource: timebase mult[2800000] shift[24] registered
Console: colour dummy device 80x25
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 16384 (order: 5, 131072 bytes, linear)
Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes, linear)
e6500 family performance monitor hardware support registered
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 24 CPUs

在 2020/4/25 1:17, Daniel Axtens 写道:

Hi Jason,

Apologies for the delay in testing.

I'm seeing this problem when I try to boot on a t4240rdb:

random: get_random_u64 called from .start_kernel+0x734/0x964 with crng_init=0 [8/973]
clocksource: timebase: mask: 0xffffffffffffffff max_cycles: 0xa9210e89c, max_idle_ns: 440795203878 ns
clocksource: timebase mult[15d17460] shift[24] registered
Console: colour dummy device 80x25
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 16384 (order: 5, 131072 bytes, linear)
Mountpoint-cache hash table entries: 16384 (order: 5, 131072 bytes, linear)
e6500 family performance monitor hardware support registered
rcu: Hierarchical SRCU implementation.
smp: Bringing up secondary CPUs ...
Processor 2 is stuck.
Processor 3 is stuck.
Processor 4 is stuck.
Processor 5 is stuck.
Processor 6 is stuck.
Processor 7 is stuck.
Processor 8 is stuck.
Processor 9 is stuck.
Processor 10 is stuck.
Processor 11 is stuck.
Processor 12 is stuck.
Processor 13 is stuck.
Processor 14 is stuck.
...
Processor 22 is stuck.
Processor 23 is stuck.
smp: Brought up 1 node, 2 CPUs
Using standard scheduler topology
devtmpfs: initialized
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
futex hash table entries: 8192 (order: 7, 524288 bytes, linear)
NET: Registered protocol family 16
audit: initializing netlink subsys (disabled)
audit: type=2000 audit(108.032:1): state=initialized audit_enabled=0 res=1
Machine: fsl,T4240RDB
SoC family: QorIQ T4240
SoC ID: svr:0x82480020, Revision: 2.0
... boot continues ...

If I boot with nokaslr, all the CPUs come up with no issue.

This is on top of powerpc/merge at
8299da600ad05b8aa0f15ec0f5f03bd40e37d6f0. If you'd like me to test any
debug patches I can do that.

I've attached my .config.

Regards,
Daniel

This is a try to implement KASLR for Freescale BookE64 which is based on
my earlier implementation for Freescale BookE32:
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=131718&state=*

The implementation for Freescale BookE64 is similar as BookE32. One
difference is that Freescale BookE64 set up a TLB mapping of 1G during
booting. Another difference is that ppc64 needs the kernel to be
64K-aligned. So we can randomize the kernel in this 1G mapping and make
it 64K-aligned. This can save some code to creat another TLB map at
early boot. The disadvantage is that we only have about 1G/64K = 16384
slots to put the kernel in.

KERNELBASE

64K |--> kernel <--|
| | |
+--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+
| | | |....| | | | | | | | | |....| | |
+--+--+--+ +--+--+--+--+--+--+--+--+--+ +--+--+
| | 1G
|-----> offset <-----|

kernstart_virt_addr

I'm not sure if the slot numbers is enough or the design has any
defects. If you have some better ideas, I would be happy to hear that.

Thank you all.

v4->v5:
Fix "-Werror=maybe-uninitialized" compile error.
Fix typo "similar as" -> "similar to".
v3->v4:
Do not define __kaslr_offset as a fixed symbol. Reference __run_at_load and
__kaslr_offset by symbol instead of magic offsets.
Use IS_ENABLED(CONFIG_PPC32) instead of #ifdef CONFIG_PPC32.
Change kaslr-booke32 to kaslr-booke in index.rst
Switch some instructions to 64-bit.
v2->v3:
Fix build error when KASLR is disabled.
v1->v2:
Add __kaslr_offset for the secondary cpu boot up.

Jason Yan (6):
powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and
kaslr_early_init()
powerpc/fsl_booke/64: introduce reloc_kernel_entry() helper
powerpc/fsl_booke/64: implement KASLR for fsl_booke64
powerpc/fsl_booke/64: do not clear the BSS for the second pass
powerpc/fsl_booke/64: clear the original kernel if randomized
powerpc/fsl_booke/kaslr: rename kaslr-booke32.rst to kaslr-booke.rst
and add 64bit part

Documentation/powerpc/index.rst | 2 +-
.../{kaslr-booke32.rst => kaslr-booke.rst} | 35 ++++++-
arch/powerpc/Kconfig | 2 +-
arch/powerpc/kernel/exceptions-64e.S | 23 +++++
arch/powerpc/kernel/head_64.S | 13 +++
arch/powerpc/kernel/setup_64.c | 3 +
arch/powerpc/mm/mmu_decl.h | 23 +++--
arch/powerpc/mm/nohash/kaslr_booke.c | 91 +++++++++++++------
8 files changed, 147 insertions(+), 45 deletions(-)
rename Documentation/powerpc/{kaslr-booke32.rst => kaslr-booke.rst} (59%)

--
2.17.2

Next message: David Miller: "Re: [PATCH V2 net-next 0/9] net: hns3: refactor for MAC table"
Previous message: Aisheng Dong: "RE: [PATCH V2 02/10] clk: imx8m: drop clk_hw_set_parent for A53"
In reply to: Daniel Axtens: "Re: [PATCH v5 0/6] implement KASLR for powerpc/fsl_booke/64"
Next in thread: Daniel Axtens: "Re: [PATCH v5 0/6] implement KASLR for powerpc/fsl_booke/64"
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