[LTP] LTP cve-2017-5754 meltdown intermittent failure on mainline kernel

[Jan Stancek]

----- Original Message -----
> LTP cve-2017-5754 meltdown test failed intermittently on qemu_x86_64
> running mainline kernel. Not easy to reproduce.

This has been reported by Li couple weeks back:
  http://lists.linux.it/pipermail/ltp/2018-April/007893.html

Conclusion at the time was we need to improve the testcase
to cope with 8c06c774 (x86/pti: Leave kernel text global for !PCID)​.

> 
> Linux kernel version: 4.18.0-rc1
> qemu-system-x86 version: 2.12
> 
> Test output:
> tst_test.c:1015: INFO: Timeout per run is 0h 15m 00s
> meltdown.c:259: INFO:
>  access time: cached = 48, uncached = 378, threshold = 134
> meltdown.c:309: INFO: linux_proc_banner is at ffffffffaac00020
> meltdown.c:332: INFO: read ffffffffaac00020 = 0x21 !
> meltdown.c:332: INFO: read ffffffffaac00021 = 0x73 s
> meltdown.c:332: INFO: read ffffffffaac00022 = 0x20
> meltdown.c:332: INFO: read ffffffffaac00023 = 0x76 v
> meltdown.c:332: INFO: read ffffffffaac00024 = 0x5
> meltdown.c:332: INFO: read ffffffffaac00025 = 0x72 r
> meltdown.c:332: INFO: read ffffffffaac00026 = 0x53 S
> meltdown.c:332: INFO: read ffffffffaac00027 = 0x69 i
> meltdown.c:332: INFO: read ffffffffaac00028 = 0x61 a
> meltdown.c:332: INFO: read ffffffffaac00029 = 0x6e n
> meltdown.c:332: INFO: read ffffffffaac0002a = 0x20
> meltdown.c:332: INFO: read ffffffffaac0002b = 0x25 %
> meltdown.c:332: INFO: read ffffffffaac0002c = 0x73 s
> meltdown.c:342: FAIL: I was able to read your kernel memory!!!
> Summary:
> passed   0
> failed   1
> skipped  0
> warnings 0
> 
> Failed full log can be found here in these links,
> https://lkft.validation.linaro.org/scheduler/job/261698#L8280
> https://lkft.validation.linaro.org/scheduler/job/290417#L10464
> 
> Best regards
> Naresh Kamboju
>