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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	npiggin@gmail.com
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 25/43] powerpc/32: Replace ASM exception exit by C exception exit from ppc64
Date: Thu, 11 Mar 2021 20:39:04 +0100	[thread overview]
Message-ID: <0296d1bc-b37e-43c8-06cf-00ec458fb74e@csgroup.eu> (raw)
In-Reply-To: <87tuphkdkz.fsf@mpe.ellerman.id.au>



Le 11/03/2021 à 14:46, Michael Ellerman a écrit :
> Christophe Leroy <christophe.leroy@csgroup.eu> writes:
>> This patch replaces the PPC32 ASM exception exit by C exception exit.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>   arch/powerpc/kernel/entry_32.S  | 481 +++++++++-----------------------
>>   arch/powerpc/kernel/interrupt.c |   4 +
>>   2 files changed, 132 insertions(+), 353 deletions(-)
> 
> Bisect points to this breaking qemu mac99 for me, with pmac32_defconfig.
> 
> I haven't had time to dig any deeper sorry.

Embarrasing ...

I don't get this problem on the 8xx (nohash/32) or the 83xx (book3s/32).
I don't get this problem with qemu mac99 when using my klibc-based initramfs.

I managed to reproduce it with the rootfs.cpio that I got some time ago from linuxppc github Wiki.

I'll investigate it tomorrow.

Thanks
Christophe


> 
> cheers
> 
> 
> Freeing unused kernel memory: 1132K
> This architecture does not have kernel memory protection.
> Run /init as init process
> init[1]: User access of kernel address (fffffd20) - exploit attempt? (uid: 0)
> init[1]: segfault (11) at fffffd20 nip b7e78638 lr b7e845e4 code 1 in ld-2.27.so[b7e6b000+22000]
> init[1]: code: 92010080 92210084 92410088 92810090 92a10094 92c10098 930100a0 932100a4
> init[1]: code: 934100a8 936100ac 93a100b4 91810074 <7d41496e> 39400000 3b810017 579c0036
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x00ERROR: Error: saw oops/warning etc. while expecting
> 00000b
> CPU: 0 PID: 1 Comm: init Not tainted 5.12.0-rc2+ #1
> Call Trace:
> [f1019d80] [c004f1ec] panic+0x138/0x328 (unreliable)
> [f1019de0] [c0051c8c] do_exit+0x880/0x8f4
> [f1019e30] [c0052bdc] do_group_exit+0x40/0xa4
> [f1019e50] [c0060d04] get_signal+0x1e8/0x834
> [f1019eb0] [c000b624] do_notify_resume+0xc8/0x314
> [f1019f10] [c0010da8] interrupt_exit_user_prepare+0xa4/0xdc
> [f1019f30] [c0018228] interrupt_return+0x14/0x14c
> --- interrupt: 300 at 0xb7e78638
> NIP:  b7e78638 LR: b7e845e4 CTR: c01ea2d8
> REGS: f1019f40 TRAP: 0300   Not tainted  (5.12.0-rc2+)
> MSR:  0000d032 <EE,PR,ME,IR,DR,RI>  CR: 28004422  XER: 20000000
> DAR: fffffd20 DSISR: 42000000
> GPR00: b7e845e4 bf951440 00000000 bf951460 00000000 bf951718 fefefeff 7f7f7f7f
> GPR08: bf9516b0 406ae8e0 b7eac1d4 00000000 0a12247b 00000000 b7e8a0d0 b7e78554
> GPR16: bf951730 bf9516f0 b7eaaf40 bf9516f0 00000001 b7eaa688 10002178 bf951460
> GPR24: 00000000 00000000 b7eac200 100cff38 bf9516f0 10002179 b7e845e4 bf951440
> NIP [b7e78638] 0xb7e78638
> LR [b7e845e4] 0xb7e845e4
> --- interrupt: 300
> Rebooting in 180 seconds..
> 

  reply	other threads:[~2021-03-11 19:39 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-09 12:09 [PATCH v2 00/43] powerpc/32: Switch to interrupt entry/exit in C Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 01/43] powerpc/traps: unrecoverable_exception() is not an interrupt handler Christophe Leroy
2021-03-10  1:16   ` Nicholas Piggin
2021-03-09 12:09 ` [PATCH v2 02/43] powerpc/traps: Declare unrecoverable_exception() as __noreturn Christophe Leroy
2021-03-10  1:22   ` Nicholas Piggin
2021-03-12  8:40     ` Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 03/43] powerpc/40x: Don't use SPRN_SPRG_SCRATCH0/1 in TLB miss handlers Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 04/43] powerpc/40x: Change CRITICAL_EXCEPTION_PROLOG macro to a gas macro Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 05/43] powerpc/40x: Save SRR0/SRR1 and r10/r11 earlier in critical exception Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 06/43] powerpc/40x: Reorder a few instructions in critical exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 07/43] powerpc/40x: Prepare for enabling MMU " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 08/43] powerpc/40x: Prepare normal exception handler for enabling MMU early Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 09/43] powerpc/32: Reconcile interrupts in C Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 10/43] powerpc/32: Entry cpu time accounting " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 11/43] powerpc/32: Handle bookE debugging in C in exception entry Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 12/43] powerpc/32: Use fast instruction to set MSR RI in exception prolog on 8xx Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 13/43] powerpc/32: Remove ksp_limit Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 14/43] powerpc/32: Always enable data translation in exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 15/43] powerpc/32: Tag DAR in EXCEPTION_PROLOG_2 for the 8xx Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 16/43] powerpc/32: Enable instruction translation at the same time as data translation Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 17/43] powerpc/32: Statically initialise first emergency context Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 18/43] powerpc/32: Add vmap_stack_overflow label inside the macro Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 19/43] powerpc/32: Use START_EXCEPTION() as much as possible Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 20/43] powerpc/32: Move exception prolog code into .text once MMU is back on Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 21/43] powerpc/32: Provide a name to exception prolog continuation in virtual mode Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 22/43] powerpc/32: Refactor booke critical registers saving Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 23/43] powerpc/32: Perform normal function call in exception entry Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 24/43] powerpc/32: Always save non volatile registers on " Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 25/43] powerpc/32: Replace ASM exception exit by C exception exit from ppc64 Christophe Leroy
2021-03-11 13:46   ` Michael Ellerman
2021-03-11 19:39     ` Christophe Leroy [this message]
2021-03-11 23:26       ` Michael Ellerman
2021-03-12  8:28         ` Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 26/43] powerpc/32: Set regs parameter in r3 in transfer_to_handler Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 27/43] powerpc/32: Call bad_page_fault() from do_page_fault() Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 28/43] powerpc/64e: " Christophe Leroy
2021-03-10  1:29   ` Nicholas Piggin
2021-03-12  8:39     ` Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 29/43] powerpc/32: Save trap number on stack in exception prolog Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 30/43] powerpc/32: Add a prepare_transfer_to_handler macro for exception prologs Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 31/43] powerpc/32: Only restore non volatile registers when required Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 32/43] powerpc/32: Dismantle EXC_XFER_STD/LITE/TEMPLATE Christophe Leroy
2021-03-09 12:09 ` [PATCH v2 33/43] powerpc/32: Remove the xfer parameter in EXCEPTION() macro Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 34/43] powerpc/32: Refactor saving of volatile registers in exception prologs Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 35/43] powerpc/32: Save remaining registers in exception prolog Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 36/43] powerpc/32: Set current->thread.regs in C interrupt entry Christophe Leroy
2021-03-10  1:33   ` Nicholas Piggin
2021-03-11 10:38     ` Christophe Leroy
2021-03-11 12:38       ` Christophe Leroy
2021-03-12  1:00         ` Nicholas Piggin
2021-03-09 12:10 ` [PATCH v2 37/43] powerpc/32: Return directly from power_save_ppc32_restore() Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 38/43] powerpc/32: Only use prepare_transfer_to_handler function on book3s/32 and e500 Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 39/43] powerpc/32s: Move KUEP locking/unlocking in C Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 40/43] powerpc/64s: Make kuap_check_amr() and kuap_get_and_check_amr() generic Christophe Leroy
2021-03-10  1:37   ` Nicholas Piggin
2021-03-12  8:37     ` Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 41/43] powerpc/32s: Create C version of kuap save/restore/check helpers Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 42/43] powerpc/8xx: " Christophe Leroy
2021-03-09 12:10 ` [PATCH v2 43/43] powerpc/32: Manage KUAP in C Christophe Leroy
2021-03-14 10:01 ` [PATCH v2 00/43] powerpc/32: Switch to interrupt entry/exit " Michael Ellerman

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