Oops decoding help request
Hello,
I am not a kernel developer and I need much help in order to understand
a kernel Oops (the first of a series of three Oops). It is:
kernel tried to execute exec-protected page (f102) - exploit attempt? (uid:
0)
BUG: Unable to handle kernel instruction fetch
Faulting instruction address: 0xf102
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K MMU=Hash PowerMac
Modules linked in: crct10dif_generic (+) crct10dif_common
drm_panel_orientation_quirks
CPU: 0 PID: 71 Comm: systemd-udevd Not tainted 5.9.0-rc1+ #298
NIP: f102 LR: c00053a4 CTR: f102
REGS: c1c6dd50 TRAP: 0400 Not tainted (5.9.0-rc1+)
MSR: 10009032 CR: 2284 XER:
GPR00: c0005390 c1c6de08 c1c6b400 0cc0 0008 ef6db038 0001
GPR08: 002e 2284 00b6fb58 0005
GPR16: bff0d768 bff0d770 01032cc0 00b0b31f 01020960
GPR24: 00b70954 010206c0 ef39f4a0 00a28380 f102 f10193a0
NIP [f102] crct10dif_mod_init+0x0/0x60 [crct10dif_generic]
LR [c00053a4] do_one_initcall+0x50/0x1f4
Call Trace:
[c1c6de08] [c0005390] do_one_initcall+0x3c/0x1f4 (unreliable)
[c1c6de78] [c0102068] do_init_module+0x6c/0x27c
[c1c6dea8] [c01053cc] sys_finit_module+0xc0/0x12c
[c1c6df38] [c001c11c] ret_from_syscall+0x0/0x34
--- interrupt: c01 at 0x7a7780
LR = 0xa1bf64
Instruction dump:
<7c0802a6> 90010004 6000 9421fff0
---[ end trace 257a4bbda691894e ]---
>From what I understand, this is a problem in the init function of
module crct10dif_generic jumping at address f102.
I think I understand that f102 is an address for data and not for
code. In fact it belongs to "vmalloc & ioremap" area of the virtual
memory layout:
* 0xffbee000..0xf000 : fixmap
* 0xff40..0xff80 : highmem PTEs
* 0xfda27000..0xff40 : early ioremap
* 0xf100..0xfda27000 : vmalloc & ioremap
The init function is:
:
0: 7c 08 02 a6 mflrr0
4: 90 01 00 04 stw r0,4(r1)
8: 48 00 00 01 bl 8
c: 94 21 ff f0 stwur1,-16(r1)
10: 7c 08 02 a6 mflrr0
14: 3c 60 00 00 lis r3,0
18: 90 01 00 14 stw r0,20(r1)
1c: 38 63 00 00 addir3,r3,0
20: 80 01 00 14 lwz r0,20(r1)
24: 38 21 00 10 addir1,r1,16
28: 7c 08 03 a6 mtlrr0
2c: 48 00 00 00 b 2c
and its source code is:
static int __init crct10dif_mod_init(void)
{
return crypto_register_shash();
}
This is what I am not understanding. The error message seems to imply
that code jumps to an invalid address, so the problem would be that
address of function crypto_register_shash is calculated wrongly.
About stack addresses, please note that CONFIG_VMAP_STACK is not set.
Is this a correct reasoning?
Thank you very much,
Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Christophe, Il giorno lun, 24/08/2020 alle 07.17 +0200, Christophe Leroy ha scritto: > Hello Giuseppe, [...] > The Oopses in the video are fixed in 5.9-rc2, see my response to your > other mail. Right, I just updated from git and rebuilt the kernel whith CONFIG_VMAP_STACK not set and the machine boots correctly. > So now we know that your kernel doesn't boot when CONFIG_VMAP_STACK is set. > Can you remind the exact problem ? latest kernel with CONFIG_VMAP_STACK set stops after writing: pmac32_cpufreq: registering PowerMac CPU frequency driver pmac32_cpufreq: Low: 667 MHz, High: 867 Mhz, Boot: 667 MHz > One common problem with CONFIG_VMAP_STACK is when some drivers are > invalidly using buffers in stack for DMA. > > Couldn't try with CONFIG_DEBUG_VIRTUAL (without CONFIG_VMAP_STACK) and > see if it triggers some warnings ? I've just tried: it boots without any special warning. What should I look for? This is an excerpt of dmesg output about the line it would otherwise stop: [...] [6.566984] PowerMac i2c bus pmu 2 registered [6.574879] PowerMac i2c bus pmu 1 registered [6.582634] PowerMac i2c bus mac-io 0 registered [6.590323] i2c i2c-2: No i2c address for /pci@f200/mac-io@17/i2c@18000/i2c-modem [6.598290] PowerMac i2c bus uni-n 1 registered [6.606196] i2c i2c-3: i2c-powermac: modalias failure on /uni-n@f800/i2c@f8001000/cereal@1c0 [6.614320] PowerMac i2c bus uni-n 0 registered [6.622501] pmac32_cpufreq: Registering PowerMac CPU frequency driver [6.630580] pmac32_cpufreq: Low: 667 Mhz, High: 867 Mhz, Boot: 667 Mhz [6.639518] ledtrig-cpu: registered to indicate activity on CPUs [6.647894] NET: Registered protocol family 10 [6.656492] Segment Routing with IPv6 [6.664490] mip6: Mobile IPv6 [6.672337] NET: Registered protocol family 17 [6.680213] mpls_gso: MPLS GSO support [...] Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello, Il giorno ven, 21/08/2020 alle 16.03 +0200, Christophe Leroy ha scritto: [...] > Thanks. > > The Oops in the video shows that the issue is at 0x1bcac and msr > value > shows that Instruction MMU is disabled. So this corresponds to > address > 0xc001bcac. In the vmlinux you sent me this address is in > power_save_ppc32_restore() > > This issue is fixed by > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/7bce32ccbab3ba3e3e0f27da6961bf6313df97ed.1581663140.git.christophe.le...@c-s.fr/ > > > You also said in a previous mail that your original issue also > happens > when CONFIG_VMAP_STACK is not selected. The above bug being linked > to > CONFIG_VMAP_STACK, maybe it would be easier to bisect with > CONFIG_VMAP_STACK unselected. I rebuilt the same kernel that I would otherwise have skipped because of the other bug, and it worked, indeed. I will continue my "bisect quest" unselecting VMAP_STACK in order to speed up the bisecting. Thank you very much, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Cristophe, Il giorno ven, 21/08/2020 alle 08.55 +0200, Christophe Leroy ha scritto: > Hi Giuseppe, > > Le 08/07/2020 à 20:44, Christophe Leroy a écrit : > > > > Le 08/07/2020 à 19:36, Giuseppe Sacco a écrit : > > > Hi Cristophe, > > > > > > Il giorno mer, 08/07/2020 alle 19.09 +0200, Christophe Leroy ha > > > scritto: [...] > > > > What's the result with: > > > > > > > > LANG=C make ARCH=powerpc CROSS_COMPILE=powerpc-linux- vmlinux > > > > > > $ LANG=C make ARCH=powerpc CROSS_COMPILE=powerpc-linux- vmlinux > > >CALLscripts/checksyscalls.sh > > >CALLscripts/atomic/check-atomics.sh > > >CHK include/generated/compile.h > > >CC kernel/module.o > > > kernel/module.c: In function 'do_init_module': > > > kernel/module.c:3593:2: error: implicit declaration of function > > > 'module_enable_ro'; did you mean 'module_enable_x'? [-Werror=implicit- > > > function-declaration] > > > 3593 | module_enable_ro(mod, true); > > >| ^~~~ > > >| module_enable_x > > > cc1: some warnings being treated as errors > > > make[1]: *** [scripts/Makefile.build:267: kernel/module.o] Error 1 > > > make: *** [Makefile:1735: kernel] Error 2 > > > > > > So, should I 'git bisect skip'? > > > > Ah yes, I had the exact same problem last time I bisected. > > > > So yes do 'git bisect skip'. You'll probably hit this problem half a > > dozen of times, but at the end you should get a usefull bisect anyway. > > > > Were you able to progress ? Very slowly. I am still working on it, currently at recompile #276. git-bisect states that I have still about 700 commits to check, but the real problem is that more than 60% of built kernels crash even before displaying the cpu_freq message (probably another long lasting bug hides the one I am looking for). All these skipped kernels make bisecting very very slow. A short video about the problem I face when I skip the build is here: https://eppesuigoccas.homedns.org/~giuseppe/bug%20avvio%20powerbook%20g4.mp4 Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Christophe, Il giorno ven, 21/08/2020 alle 16.03 +0200, Christophe Leroy ha scritto: [...] > Thanks. > > The Oops in the video shows that the issue is at 0x1bcac and msr > value > shows that Instruction MMU is disabled. So this corresponds to > address > 0xc001bcac. In the vmlinux you sent me this address is in > power_save_ppc32_restore() > > This issue is fixed by > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/7bce32ccbab3ba3e3e0f27da6961bf6313df97ed.1581663140.git.christophe.le...@c-s.fr/ > > > You also said in a previous mail that your original issue also > happens > when CONFIG_VMAP_STACK is not selected. The above bug being linked > to > CONFIG_VMAP_STACK, maybe it would be easier to bisect with > CONFIG_VMAP_STACK unselected. I was wrong. Disabling CONFIG_VMAP_STACK led me to all "good" compile and bisect ended without finding the culprit commit. So, I started from scratch: I rebuilt HEAD and found that it does show the original problem I am facing, then I rebuilt it without CONFIG_VMAP_STACK and found that it does pass (fix?) the problem, since kernel continue booting, but then it stops with three Oops related to command systemd-udevd. You may find a video that displays the complete boot, vmlinux, config, and system.map files here: https://eppesuigoccas.homedns.org/~giuseppe/powerpc32/config-5.9.0-rc1+ https://eppesuigoccas.homedns.org/~giuseppe/powerpc32/System.map https://eppesuigoccas.homedns.org/~giuseppe/powerpc32/VID_20200822_095621.mp4 https://eppesuigoccas.homedns.org/~giuseppe/powerpc32/vmlinux.strip.gz Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Il giorno gio, 27/08/2020 alle 09.46 +0200, Giuseppe Sacco ha scritto: > Il giorno gio, 27/08/2020 alle 00.28 +0200, Giuseppe Sacco ha scritto: > > Hello Christophe, > > > > Il giorno mer, 26/08/2020 alle 15.53 +0200, Christophe Leroy ha > > scritto: > > [...] > > > If there is no warning, then the issue is something else, bad luck. > > > > > > Could you increase the loglevel and try again both with and without > > > VMAP_STACK ? Maybe we'll get more information on where it stops. > > > > The problem is related to the CPU frequency changes. This is where the > > system stop: cpufreq get the CPU frequency limits and then start the > > default governor (performance) and then calls function > > cpufreq_gov_performance_limits() that never returns. > > > > Rebuilding after enabling pr_debug for cpufreq.c, I've got some more > > lines of output: > > > > cpufreq: setting new policy for CPU 0: 667000 - 867000 kHz > > cpufreq: new min and max freqs are 667000 - 867000 kHz > > cpufreq: governor switch > > cpufreq: cpufreq_init_governor: for CPU 0 > > cpufreq: cpufreq_start_governor: for CPU 0 > > cpufreq: target for CPU 0: 867000 kHz, relation 1, requested 867000 kHz > > cpufreq: __target_index: cpu: 0, oldfreq: 667000, new freq: 867000 > > cpufreq: notification 0 of frequency transition to 867000 kHz > > cpufreq: saving 133328 as reference value for loops_per_jiffy; freq is > > 667000 kHz > > > > no more lines are printed. I think this output only refers to the > > notification sent prior to the frequency change. > > > > I was thinking that selecting a governor that would run at 667mHz would > > probably skip the problem. I added cpufreq.default_governor=powersave > > to the command line parameters but it did not work: the selected > > governor was still performance and the system crashed. > > I kept following the thread and found that CPU frequency is changed in > function pmu_set_cpu_speed() in file drivers/cpufreq/pmac32-cpufreq.c. > As first thing, the function calls the macro preempt_disable() and this > is where it stops. Sorry, I made a mistake. The real problem is down, on the same function, when it calls low_sleep_handler(). This is where the problem probably is. Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Christophe, Il giorno mer, 26/08/2020 alle 15.53 +0200, Christophe Leroy ha scritto: [...] > If there is no warning, then the issue is something else, bad luck. > > Could you increase the loglevel and try again both with and without > VMAP_STACK ? Maybe we'll get more information on where it stops. The problem is related to the CPU frequency changes. This is where the system stop: cpufreq get the CPU frequency limits and then start the default governor (performance) and then calls function cpufreq_gov_performance_limits() that never returns. Rebuilding after enabling pr_debug for cpufreq.c, I've got some more lines of output: cpufreq: setting new policy for CPU 0: 667000 - 867000 kHz cpufreq: new min and max freqs are 667000 - 867000 kHz cpufreq: governor switch cpufreq: cpufreq_init_governor: for CPU 0 cpufreq: cpufreq_start_governor: for CPU 0 cpufreq: target for CPU 0: 867000 kHz, relation 1, requested 867000 kHz cpufreq: __target_index: cpu: 0, oldfreq: 667000, new freq: 867000 cpufreq: notification 0 of frequency transition to 867000 kHz cpufreq: saving 133328 as reference value for loops_per_jiffy; freq is 667000 kHz no more lines are printed. I think this output only refers to the notification sent prior to the frequency change. I was thinking that selecting a governor that would run at 667mHz would probably skip the problem. I added cpufreq.default_governor=powersave to the command line parameters but it did not work: the selected governor was still performance and the system crashed. Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Il giorno gio, 27/08/2020 alle 00.28 +0200, Giuseppe Sacco ha scritto: > Hello Christophe, > > Il giorno mer, 26/08/2020 alle 15.53 +0200, Christophe Leroy ha > scritto: > [...] > > If there is no warning, then the issue is something else, bad luck. > > > > Could you increase the loglevel and try again both with and without > > VMAP_STACK ? Maybe we'll get more information on where it stops. > > The problem is related to the CPU frequency changes. This is where the > system stop: cpufreq get the CPU frequency limits and then start the > default governor (performance) and then calls function > cpufreq_gov_performance_limits() that never returns. > > Rebuilding after enabling pr_debug for cpufreq.c, I've got some more > lines of output: > > cpufreq: setting new policy for CPU 0: 667000 - 867000 kHz > cpufreq: new min and max freqs are 667000 - 867000 kHz > cpufreq: governor switch > cpufreq: cpufreq_init_governor: for CPU 0 > cpufreq: cpufreq_start_governor: for CPU 0 > cpufreq: target for CPU 0: 867000 kHz, relation 1, requested 867000 kHz > cpufreq: __target_index: cpu: 0, oldfreq: 667000, new freq: 867000 > cpufreq: notification 0 of frequency transition to 867000 kHz > cpufreq: saving 133328 as reference value for loops_per_jiffy; freq is 667000 > kHz > > no more lines are printed. I think this output only refers to the > notification sent prior to the frequency change. > > I was thinking that selecting a governor that would run at 667mHz would > probably skip the problem. I added cpufreq.default_governor=powersave > to the command line parameters but it did not work: the selected > governor was still performance and the system crashed. I kept following the thread and found that CPU frequency is changed in function pmu_set_cpu_speed() in file drivers/cpufreq/pmac32-cpufreq.c. As first thing, the function calls the macro preempt_disable() and this is where it stops. Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Il giorno gio, 27/08/2020 alle 12.39 +0200, Christophe Leroy ha scritto: > Hi, > > Le 27/08/2020 à 10:28, Giuseppe Sacco a écrit : [...] > > Sorry, I made a mistake. The real problem is down, on the same > > function, when it calls low_sleep_handler(). This is where the problem > > probably is. > > Great, you spotted the problem. > > I see what it is, it is in low_sleep_handler() in > arch/powerpc/platforms/powermac/sleep.S > > All critical registers are saved on the stack. At restore, they are > restore BEFORE re-enabling MMU (because they are needed for that). But > when we have VMAP_STACK, the stack can hardly be accessed without the > MMU enabled. tophys() doesn't work for virtual stack addresses. > > Therefore, the low_sleep_handler() has to be reworked for using an area > in the linear mem instead of the stack. I am sorry, but I don't know how to fix it. Should I open a bug for tracking this problem? Thank you, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Salut Cristophe, Il giorno mer, 08/07/2020 alle 10.38 +0200, Christophe Leroy ha scritto: > Hi Giuseppe, > > Le 08/07/2020 à 09:59, Giuseppe Sacco a écrit : > > Hello Cristophe, > > > > Il giorno mar, 07/07/2020 alle 17.34 +0200, Giuseppe Sacco ha > > scritto: [...] > > > > And can you try without CONFIG_VMAP_STACK on 5.6.19 > > > > > > Sure, I'll let you know. > > > > No, this change did not make the kernel boot. I only changed the > > option > > you proposed: > > > > $ grep VMAP .config > > CONFIG_HAVE_ARCH_VMAP_STACK=y > > # CONFIG_VMAP_STACK is not set > > > > Ok, at least it is not that. I wanted to be sure because this is a > huge > change added recently that is selected by default. > > I tried on QEMU with your config, it boots properly. > > So I think the only way now will be to bisect. Hope you were able to > setup a cross compiler on a speedy machine. thank you for your time; indeed I may now crosscompile the kernel in 15 minutes instead of about 390... I hope to have a final result in a couple of days. Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Cristophe, Il giorno mar, 07/07/2020 alle 17.34 +0200, Giuseppe Sacco ha scritto: > Il giorno mar, 07/07/2020 alle 16.52 +0200, Christophe Leroy ha > scritto: > > Le 07/07/2020 à 16:03, Giuseppe Sacco a écrit : > > > Hello Cristophe, > > > > > > > Can you tell which defconfig you use or provide your .config > > > > > > You may get the standard one from debian or a reduced one that I > > > made on purpose. The latter is here: > > > https://eppesuigoccas.homedns.org/~giuseppe/config-5.4.50.gz > > > > > > (boot) > > > https://eppesuigoccas.homedns.org/~giuseppe/config-5.6.19.gz > > > > > > (no boot) > > > > Thanks > > > > Can you provide the complete output when it works, so that I can > > see > > what is after the place it stops when it fails. > > Here it is: > https://eppesuigoccas.homedns.org/~giuseppe/dmesg-5.4.40-minimo.gz > > > > And can you try without CONFIG_VMAP_STACK on 5.6.19 > > Sure, I'll let you know. No, this change did not make the kernel boot. I only changed the option you proposed: $ grep VMAP .config CONFIG_HAVE_ARCH_VMAP_STACK=y # CONFIG_VMAP_STACK is not set Thanks, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello, while trying to debug a problem using git bisect, I am now at a point where I cannot build the kernel at all. This is the error message I get: $ LANG=C make ARCH=powerpc \ CROSS_COMPILE=powerpc-linux- \ CONFIG_MODULE_COMPRESS_GZIP=true \ INSTALL_MOD_STRIP=1 CONFIG_MODULE_COMPRESS=1 \ -j4 INSTALL_MOD_PATH=$BOOT INSTALL_PATH=$BOOT \ CONFIG_DEBUG_INFO_COMPRESSED=1 \ install modules_install make[2]: *** No rule to make target 'vmlinux', needed by 'arch/powerpc/boot/zImage.pmac'. Stop. make[1]: *** [arch/powerpc/Makefile:407: install] Error 2 make: *** [Makefile:328: __build_one_by_one] Error 2 How can I continue? Thank you, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hi Cristophe, Il giorno mer, 08/07/2020 alle 19.09 +0200, Christophe Leroy ha scritto: > Hi > > Le 08/07/2020 à 19:00, Giuseppe Sacco a écrit : > > Hello, > > while trying to debug a problem using git bisect, I am now at a point > > where I cannot build the kernel at all. This is the error message I > > get: > > > > $ LANG=C make ARCH=powerpc \ > > CROSS_COMPILE=powerpc-linux- \ > > CONFIG_MODULE_COMPRESS_GZIP=true \ > > INSTALL_MOD_STRIP=1 CONFIG_MODULE_COMPRESS=1 \ > > -j4 INSTALL_MOD_PATH=$BOOT INSTALL_PATH=$BOOT \ > > CONFIG_DEBUG_INFO_COMPRESSED=1 \ > > install modules_install > > make[2]: *** No rule to make target 'vmlinux', needed by > > Surprising. > > Did you make any change to Makefiles ? No > Are you in the middle of a bisect ? If so, if the previous builds > worked, I'd do 'git bisect skip' Yes, the previous one worked. > What's the result with: > > LANG=C make ARCH=powerpc CROSS_COMPILE=powerpc-linux- vmlinux $ LANG=C make ARCH=powerpc CROSS_COMPILE=powerpc-linux- vmlinux CALLscripts/checksyscalls.sh CALLscripts/atomic/check-atomics.sh CHK include/generated/compile.h CC kernel/module.o kernel/module.c: In function 'do_init_module': kernel/module.c:3593:2: error: implicit declaration of function 'module_enable_ro'; did you mean 'module_enable_x'? [-Werror=implicit- function-declaration] 3593 | module_enable_ro(mod, true); | ^~~~ | module_enable_x cc1: some warnings being treated as errors make[1]: *** [scripts/Makefile.build:267: kernel/module.o] Error 1 make: *** [Makefile:1735: kernel] Error 2 So, should I 'git bisect skip'? Thank you, Giuseppe
kernel since 5.6 do not boot anymore on Apple PowerBook
Hello, I am testing linux on a quite old hardware, an Apple PowerBook G4 "Titanium IV". I used to run Debian on this machine, so I upgraded the old operating system to the latest software and found that new kernels do not boot. I rebuilt natively (on the powerbook) a few kernels and found that 5.4.50 still works fine, while 5.6.19 and 5.7.7 stop after printing: pmac32_cpufreq: registering PowerMac CPU frequency driver pmac32_cpufreq: Low: 667 MHz, High: 867 Mhz, Boot: 667 MHz no more output is printed. I waited 5 minutes and then powered off the machine using the power button. Rebooting with old kernel works. So, I am looking for help. How may I better investigate the problem? How may I crossbuild the kernel on a faster machine (amd64) in order to try git-bisect without waiting ages? Thank you, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Hello Cristophe, Il giorno mar, 07/07/2020 alle 15.35 +0200, Christophe Leroy ha scritto: > Hi, > Le 07/07/2020 à 14:58, Giuseppe Sacco a écrit : [...] > > So, I am looking for help. How may I better investigate the > > problem? > > How may I crossbuild the kernel on a faster machine (amd64) in > > order to > > try git-bisect without waiting ages? > > To crossbuild, use cross tools at > https://mirrors.edge.kernel.org/pub/tools/crosstool/ thank you, I'll have a look at it. > Can you tell which defconfig you use or provide your .config You may get the standard one from debian or a reduced one that I made on purpose. The latter is here: https://eppesuigoccas.homedns.org/~giuseppe/config-5.4.50.gz (boot) https://eppesuigoccas.homedns.org/~giuseppe/config-5.6.19.gz (no boot) Bye, Giuseppe
Re: kernel since 5.6 do not boot anymore on Apple PowerBook
Il giorno mar, 07/07/2020 alle 16.52 +0200, Christophe Leroy ha scritto: > > Le 07/07/2020 à 16:03, Giuseppe Sacco a écrit : > > Hello Cristophe, > > > > > Can you tell which defconfig you use or provide your .config > > > > You may get the standard one from debian or a reduced one that I > > made on purpose. The latter is here: > > https://eppesuigoccas.homedns.org/~giuseppe/config-5.4.50.gz > > (boot) > > https://eppesuigoccas.homedns.org/~giuseppe/config-5.6.19.gz > > (no boot) > > Thanks > > Can you provide the complete output when it works, so that I can see > what is after the place it stops when it fails. Here it is: https://eppesuigoccas.homedns.org/~giuseppe/dmesg-5.4.40-minimo.gz > And can you try without CONFIG_VMAP_STACK on 5.6.19 Sure, I'll let you know. Thank you, Giuseppe
Re: [PATCH v2] powerpc/powermac: Fix low_sleep_handler with CONFIG_VMAP_STACK
Hello Christophe,
Il giorno mar, 08/12/2020 alle 05.24 +, Christophe Leroy ha
scritto:
> low_sleep_handler() can't restore the context from standard
> stack because the stack can hardly be accessed with MMU OFF.
>
> Store everything in a global storage area instead of storing
> a pointer to the stack in that global storage area.
>
> To avoid a complete churn of the function, still use r1 as
> the pointer to the storage area during restore.
>
> Reported-by: Giuseppe Sacco
> Fixes: cd08f109e262 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
> Signed-off-by: Christophe Leroy
> ---
> This is only build tested. Giuseppe can you test it ? Thanks.
>
> v2: Changed an erroneous 'addis' to 'addi' ; Using bss instead of
> data section
> Signed-off-by: Christophe Leroy
> ---
> arch/powerpc/platforms/Kconfig.cputype | 2 +-
> arch/powerpc/platforms/powermac/sleep.S | 132 +++---
> --
> 2 files changed, 60 insertions(+), 74 deletions(-)
[...]
I just tested the v2 patch against latest kernel. Please note that
yesterday patch was on a kernel named 5.10.0-rc6+, while today's patch
is on a kernel named 5.10.0-rc7+. Even with the latest kernel updates,
the patch apply correctly and machine boots normally, fixing the
problem.
$ uname -a
Linux titanium4 5.10.0-rc7+ #3 Tue Dec 8 09:11:20 CET 2020 ppc GNU/Linux
$ grep VMAP /boot/config-5.10.0-rc7+
CONFIG_HAVE_ARCH_VMAP_STACK=y
CONFIG_VMAP_STACK=y
Thank you again.
Bye,
Giuseppe
