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From: Phileas Fogg <phileas-fogg@mail•ru>
To: Benjamin Herrenschmidt <benh@kernel•crashing.org>
Cc: linuxppc-dev <linuxppc-dev@lists•ozlabs.org>
Subject: Re: PS3: Strange issue with kexec and FreeBSD loader
Date: Thu, 21 Feb 2013 22:44:59 +0100	[thread overview]
Message-ID: <5126955B.9070808@mail.ru> (raw)
In-Reply-To: <1361478942.4676.53.camel@pasglop>

Benjamin Herrenschmidt wrote:
> On Thu, 2013-02-21 at 21:38 +0100, Phileas Fogg wrote:
>> The new 8 bytes at offset 0x90 in dt.dump.hex look suspicously like
>> the kernel virtual address: 0xc00000000001a4a0.
>
> It does indeed. What does that address correspond to in the kernel
> text ? Can you disassemble around it with "objdump -D vmlinux" ?
>
> Cheers,
> Ben.
>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists•ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
>

Here.
I used OpenWRT ELF for testing and it's stripped.
Then i compiled Linux 3.8 myself and didn't strip it.
Addresses are different in both cases but the code is the same and
it is kexec code :)


Stripped OpenWRT image:
------------------------

c00000000001a474:       48 00 00 05     bl      0xc00000000001a478
c00000000001a478:       7c a8 02 a6     mflr    r5
c00000000001a47c:       38 a5 00 1c     addi    r5,r5,28
c00000000001a480:       7c 21 0b 78     mr      r1,r1
c00000000001a484:       80 85 00 00     lwz     r4,0(r5)
c00000000001a488:       2c 04 00 00     cmpwi   r4,0
c00000000001a48c:       40 82 00 62     bnea-   0x60
c00000000001a490:       4b ff ff f0     b       0xc00000000001a480
c00000000001a494:       00 00 00 00     .long 0x0
c00000000001a498:       a0 6d 00 48     lhz     r3,72(r13)
c00000000001a49c:       48 00 00 11     bl      0xc00000000001a4ac
c00000000001a4a0:       38 80 00 02     li      r4,2              <-------- !!!
c00000000001a4a4:       98 8d 00 4b     stb     r4,75(r13)
c00000000001a4a8:       4b ff ff cc     b       0xc00000000001a474
c00000000001a4ac:       39 20 00 02     li      r9,2
c00000000001a4b0:       39 40 00 30     li      r10,48
c00000000001a4b4:       7d 68 02 a6     mflr    r11
c00000000001a4b8:       7d 80 00 a6     mfmsr   r12
c00000000001a4bc:       7d 89 48 78     andc    r9,r12,r9
c00000000001a4c0:       7d 8a 50 78     andc    r10,r12,r10
c00000000001a4c4:       7d 21 01 64     mtmsrd  r9,1



Unstripped Linux 3.8 kernel:
-----------------------------


c00000000001c02c <.kexec_wait>:
c00000000001c02c:       48 00 00 05     bl      c00000000001c030 <.kexec_wait+0x4>
c00000000001c030:       7c a8 02 a6     mflr    r5
c00000000001c034:       38 a5 00 1c     addi    r5,r5,28
c00000000001c038:       7c 21 0b 78     mr      r1,r1
c00000000001c03c:       80 85 00 00     lwz     r4,0(r5)
c00000000001c040:       2c 04 00 00     cmpwi   r4,0
c00000000001c044:       40 82 00 62     bnea-   60 <reloc_start+0x60>
c00000000001c048:       4b ff ff f0     b       c00000000001c038 <.kexec_wait+0xc>

c00000000001c04c <kexec_flag>:
c00000000001c04c:       00 00 00 00     .long 0x0

c00000000001c050 <.kexec_smp_wait>:
c00000000001c050:       a0 6d 00 48     lhz     r3,72(r13)
c00000000001c054:       48 00 00 11     bl      c00000000001c064 <real_mode>
c00000000001c058:       38 80 00 02     li      r4,2        <---------- !!!
c00000000001c05c:       98 8d 00 4b     stb     r4,75(r13)
c00000000001c060:       4b ff ff cc     b       c00000000001c02c <.kexec_wait>

c00000000001c064 <real_mode>:
c00000000001c064:       39 20 00 02     li      r9,2
c00000000001c068:       39 40 00 30     li      r10,48


regards

  reply	other threads:[~2013-02-21 20:45 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-08 23:10 PS3: Strange issue with kexec and FreeBSD loader Phileas Fogg
2013-02-16 10:53 ` Phileas Fogg
2013-02-16 22:14   ` Phileas Fogg
2013-02-16 23:12   ` Phileas Fogg
2013-02-17  8:53     ` Geert Uytterhoeven
2013-02-17 12:40       ` Phileas Fogg
2013-02-21  0:14     ` Geoff Levand
2013-02-16 18:51 ` Phileas Fogg
2013-02-19 18:40 ` Phileas Fogg
2013-02-19 19:54   ` Phileas Fogg
2013-02-20 20:43     ` Phileas Fogg
2013-02-21  0:32       ` Benjamin Herrenschmidt
2013-02-21 20:38         ` Phileas Fogg
2013-02-21 20:35           ` Benjamin Herrenschmidt
2013-02-21 21:44             ` Phileas Fogg [this message]
2013-02-21 23:46               ` Benjamin Herrenschmidt
2013-02-22 20:49                 ` Phileas Fogg
2013-02-22 19:52                   ` Benjamin Herrenschmidt
2013-02-22 23:41                     ` Phileas Fogg
2013-02-22 22:45                       ` Benjamin Herrenschmidt
2013-02-22 23:53                         ` Phileas Fogg
2013-02-21 22:06             ` Phileas Fogg
2013-02-21 23:47               ` Benjamin Herrenschmidt

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