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Date:   Tue, 20 Apr 2021 10:48:18 +0800
From:   Huang Pei <huangpei@loongson.cn>
To:     Zhou Yanjie <zhouyanjie@wanyeetech.com>
Cc:     tsbogend@alpha.franken.de, linux-mips@vger.kernel.org,
        linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        paul.burton@mips.com, paul@crapouillou.net, siyanteng@loongson.cn,
        ira.weiny@intel.com, yangtiezhu@loongson.cn, jun.jiang@ingenic.com,
        dongsheng.qiu@ingenic.com, aric.pzqi@ingenic.com,
        rick.tyliu@ingenic.com, sernia.zhou@foxmail.com
Subject: Re: [PATCH] Revert "MIPS: make userspace mapping young by default".
Message-ID: <20210420024818.r6jf243oglb2ywbr@ambrosehua-HP-xw6600-Workstation>
References: <1618562868-91115-1-git-send-email-zhouyanjie@wanyeetech.com>
 <20210416092003.5754967.19768.9603@loongson.cn>
 <ae06522f-eda8-96d1-6f58-072905afa65c@wanyeetech.com>
 <20210419045610.frhzxskec47s5rmq@ambrosehua-HP-xw6600-Workstation>
 <13e37741-c1b4-2aae-471e-0790adc8db59@wanyeetech.com>
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Hi,
On Mon, Apr 19, 2021 at 10:21:40PM +0800, Zhou Yanjie wrote:
> Hi
> 
> On 2021/4/19 下午12:56, Huang Pei wrote:
> > On Sat, Apr 17, 2021 at 12:45:59AM +0800, Zhou Yanjie wrote:
> > > On 2021/4/16 下午5:20, 黄沛 wrote:
> > > > Is there any log about the panic?
> > > 
> > > Yes, below is the log:
> > > 
> > > 
> > > [  195.436017] CPU 0 Unable to handle kernel paging request at virtual
> > > address 77eb8000, epc == 80117868, ra == 80118208
> > > [  195.446709] Oops[#1]:
> > > [  195.448977] CPU: 0 PID: 1461 Comm: Xsession Not tainted
> > > 5.12.0-rc6-00227-gc8fc6defbd2e-dirty #1
> > > [  195.457661] $ 0   : 00000000 00000001 80117864 77eb9000
> > > [  195.462888] $ 4   : 77eb8000 82419600 838ea000 82482ba0
> > > [  195.468116] $ 8   : 826f8b18 8306f800 000072d5 8306f800
> > > [  195.473343] $12   : 00000002 00000a03 00000001 00000402
> > > [  195.478568] $16   : 77eb8000 809faf60 00000004 82482ba0
> > > [  195.483794] $20   : 77eb8000 82419600 82482ba0 80860000
> > > [  195.489021] $24   : 8086121c 80117864
> > > [  195.494248] $28   : 838ea000 838ebd70 00000000 80118208
> > > [  195.499475] Hi    : 00008c4e
> > > [  195.502343] Lo    : 00004627
> > > [  195.505212] epc   : 80117868 r4k_blast_dcache_page_dc32+0x4/0x9c
> > > [  195.511217] ra    : 80118208 local_r4k_flush_cache_page+0x120/0x1b8
> > > [  195.517476] Status: 10001403 KERNEL EXL IE
> > > [  195.521657] Cause : 4080800c (ExcCode 03)
> > > [  195.525654] BadVA : 77eb8000
> > > [  195.528523] PrId  : 00d00100 (Ingenic XBurst)
> > > [  195.532866] Modules linked in:
> > > [  195.535911] Process Xsession (pid: 1461, threadinfo=00975a3e,
> > > task=3724fd66, tls=77ebd690)
> > > [  195.544162] Stack : 808a05ec f7edcbfd 8306f800 00000000 80860000 809faf60
> > > 80990a3c 80117f90
> > > [  195.552524]         809faf60 82419600 8306f800 801fd84c 00000000 801180b4
> > > 838ebe80 80110b7c
> > > [  195.560887]         80990a3c 82482ba0 82482ba0 77eb8000 00004627 f7edcbfd
> > > 838ebe80 801cbc08
> > > [  195.569249]         00000001 181b2000 00000000 801fa06c 00000000 83999ae0
> > > 80860000 00000004
> > > [  195.577610]         80990a3c f7edcbfd 80990a3c 838ebe80 00000004 80990a3c
> > > 82482ba0 04627685
> > > [  195.585973]         ...
> > > [  195.588413] Call Trace:
> > > [  195.590849] [<80117868>] r4k_blast_dcache_page_dc32+0x4/0x9c
> > > [  195.596501] [<80118208>] local_r4k_flush_cache_page+0x120/0x1b8
> > > [  195.602413] [<80117f90>] r4k_on_each_cpu.isra.8+0x24/0x58
> > > [  195.607805] [<801180b4>] r4k_flush_cache_page+0x34/0x58
> > > [  195.613023] [<801cbc08>] wp_page_copy+0x3a8/0x56c
> > > [  195.617723] [<801ce944>] do_swap_page+0x4cc/0x558
> > > [  195.622419] [<801cf3f8>] handle_mm_fault+0x790/0x93c
> > > [  195.627374] [<8011025c>] do_page_fault+0x19c/0x540
> > > [  195.632159] [<801142f0>] tlb_do_page_fault_1+0x10c/0x11c
> > > [  195.637465]
> > > [  195.638947] Code: 03e00008  00000000  24831000 <bc950000> bc950020
> > > bc950040  bc950060  bc950080  bc9500a0
> > > [  195.648706]
> > > [  195.650243] ---[ end trace 7cc7d7f611932c42 ]---
> > > [  195.654857] Kernel panic - not syncing: Fatal exception
> > > [  195.660072] Rebooting in 10 seconds..
> > > 
> > > 
> > > this problem can be triggered stably (by use Microsoft Remote Desktop client
> > > to login to debian9 running on CU1830-Neo).
> > > 
> > Could you print out the PTE value at 0x77eb8000 ?
> 
> 
> Here is the new log:
> 
> 
> [   33.681712] CPU 0 Unable to handle kernel paging request at virtual
> address 77ea4000, epc == 801178ac, ra == 80118250
> [   33.692395] Oops[#1]:
> [   33.694662] CPU: 0 PID: 1389 Comm: Xsession Not tainted 5.12.0-rc8-dirty
> #2
> [   33.701612] $ 0   : 00000000 00000001 801178a8 77ea5000
> [   33.706839] $ 4   : 77ea4000 81bcd220 80118130 856712a0
> [   33.712066] $ 8   : 833e4a80 8544b800 000070a8 8544b800
> [   33.717293] $12   : 00000002 000005b7 00000001 00000000
> [   33.722518] $16   : 81bcd220 77ea4000 80a11ad8 00000004
> [   33.727745] $20   : 77ea4000 81bcd220 856712a0 80860000
> [   33.732972] $24   : 0000001c 801178a8
> [   33.738197] $28   : 82564000 82565d68 00000000 80118250
> [   33.743424] Hi    : 0000f0cc
> [   33.746293] Lo    : 00007866
> [   33.749162] epc   : 801178ac r4k_blast_dcache_page_dc32+0x4/0x9c
> [   33.755166] ra    : 80118250 local_r4k_flush_cache_page+0x120/0x2c8
> [   33.761425] Status: 10001403 KERNEL EXL IE
> [   33.765605] Cause : 4080800c (ExcCode 03)
> [   33.769603] BadVA : 77ea4000
> [   33.772472] PrId  : 00d00100 (Ingenic XBurst)
> [   33.776816] Modules linked in:
> [   33.779861] Process Xsession (pid: 1389, threadinfo=c8bdf64c,
> task=2372d853, tls=77ea9690)
> [   33.788111] Stack : 808a256c 00000000 808a256c bfa6939a 8544b800 80860000
> 8094d308 80a11ad8
> [   33.796474]         856712a0 80117fd8 8094d308 81bcd220 8544b800 801fdb10
> 80945ce8 801180fc
> [   33.804838]         82565e80 80110b8c 80a11ad8 856712a0 856712a0 77ea4000
> 00007866 bfa6939a
> [   33.813201]         82565e80 801cbe38 00000000 bfa6939a 80863494 801fa2c0
> 856712a0 82562a90
> [   33.821564]         80860000 00000000 80a11ad8 bfa6939a 80a11ad8 82565e80
> 00000000 80a11ad8
> [   33.829927]         ...
> [   33.832367] Call Trace:
> [   33.834803] [<801178ac>] r4k_blast_dcache_page_dc32+0x4/0x9c
> [   33.840455] [<80118250>] local_r4k_flush_cache_page+0x120/0x2c8
> [   33.846367] [<80117fd8>] r4k_on_each_cpu.isra.10+0x24/0x58
> [   33.851845] [<801180fc>] r4k_flush_cache_page+0x34/0x58
> [   33.857062] [<801cbe38>] wp_page_copy+0x3a8/0x56c
> [   33.861763] [<801ceb74>] do_swap_page+0x4cc/0x558
> [   33.866458] [<801cf628>] handle_mm_fault+0x790/0x93c
> [   33.871414] [<8011026c>] do_page_fault+0x19c/0x540
> [   33.876199] [<80114300>] tlb_do_page_fault_1+0x10c/0x11c
> [   33.881506]
> [   33.882987] Index:  5 pgmask=4kb va=77ea2000 asid=fd
> [   33.882987]  [pa=02a99000 c=3 d=1 v=1 g=0] [pa=0690d000 c=3 d=0 v=0 g=0]
> [   33.894635] Index:  6 pgmask=4kb va=77dc4000 asid=fd
> [   33.894635]  [pa=01d30000 c=3 d=0 v=1 g=0] [pa=01d31000 c=3 d=0 v=1 g=0]
> [   33.906281] Index:  7 pgmask=4kb va=77dc0000 asid=fd
> [   33.906281]  [pa=01d2c000 c=3 d=0 v=1 g=0] [pa=01d2d000 c=3 d=0 v=1 g=0]
> [   33.917928] Index:  8 pgmask=4kb va=77dc2000 asid=fd
> [   33.917928]  [pa=01d2e000 c=3 d=0 v=1 g=0] [pa=01d2f000 c=3 d=0 v=1 g=0]
> [   33.929574] Index:  9 pgmask=4kb va=77dc6000 asid=fd
> [   33.929574]  [pa=01d32000 c=3 d=0 v=1 g=0] [pa=01d33000 c=3 d=0 v=1 g=0]
> [   33.941220] Index: 10 pgmask=4kb va=77dc8000 asid=fd
> [   33.941220]  [pa=01d34000 c=3 d=0 v=1 g=0] [pa=01d35000 c=3 d=0 v=1 g=0]
> [   33.952866] Index: 11 pgmask=4kb va=77dca000 asid=fd
> [   33.952866]  [pa=01d36000 c=3 d=0 v=1 g=0] [pa=01d37000 c=3 d=0 v=1 g=0]
> [   33.964512] Index: 12 pgmask=4kb va=77dcc000 asid=fd
> [   33.964512]  [pa=01d38000 c=3 d=0 v=1 g=0] [pa=01d39000 c=3 d=0 v=1 g=0]
> [   33.976159] Index: 13 pgmask=4kb va=77dce000 asid=fd
> [   33.976159]  [pa=01d3a000 c=3 d=0 v=1 g=0] [pa=01d3b000 c=3 d=0 v=1 g=0]
> [   33.987805] Index: 14 pgmask=4kb va=77d82000 asid=fd
> [   33.987805]  [pa=01dbd000 c=3 d=0 v=1 g=0] [pa=01dbe000 c=3 d=0 v=1 g=0]
> [   33.999451] Index: 15 pgmask=4kb va=77d80000 asid=fd
> [   33.999451]  [pa=01dbb000 c=3 d=0 v=1 g=0] [pa=01dbc000 c=3 d=0 v=1 g=0]
> [   34.011097] Index: 16 pgmask=4kb va=77d84000 asid=fd
> [   34.011097]  [pa=01dbf000 c=3 d=0 v=1 g=0] [pa=01dc0000 c=3 d=0 v=1 g=0]
> [   34.022743] Index: 17 pgmask=4kb va=77d86000 asid=fd
> [   34.022743]  [pa=01dc1000 c=3 d=0 v=1 g=0] [pa=01dc2000 c=3 d=0 v=1 g=0]
> [   34.034389] Index: 18 pgmask=4kb va=77d88000 asid=fd
> [   34.034389]  [pa=01dc3000 c=3 d=0 v=1 g=0] [pa=01dc4000 c=3 d=0 v=1 g=0]
> [   34.046035] Index: 19 pgmask=4kb va=77d8a000 asid=fd
> [   34.046035]  [pa=01dc5000 c=3 d=0 v=1 g=0] [pa=01dc6000 c=3 d=0 v=1 g=0]
> [   34.057682] Index: 20 pgmask=4kb va=77d8c000 asid=fd
> [   34.057682]  [pa=01dc7000 c=3 d=0 v=1 g=0] [pa=01dc8000 c=3 d=0 v=1 g=0]
> [   34.069328] Index: 21 pgmask=4kb va=77d8e000 asid=fd
> [   34.069328]  [pa=01dc9000 c=3 d=0 v=1 g=0] [pa=01dca000 c=3 d=0 v=1 g=0]
> [   34.080975] Index: 22 pgmask=4kb va=7f7b0000 asid=fd
> [   34.080975]  [pa=078ea000 c=3 d=0 v=1 g=0] [pa=07801000 c=3 d=0 v=0 g=0]
> [   34.092621] Index: 23 pgmask=4kb va=77e5a000 asid=fd
> [   34.092621]  [pa=07ece000 c=3 d=0 v=1 g=0] [pa=077fb000 c=3 d=0 v=1 g=0]
> [   34.104267] Index: 24 pgmask=4kb va=77e5c000 asid=fd
> [   34.104267]  [pa=0775f000 c=3 d=0 v=1 g=0] [pa=07314000 c=3 d=0 v=0 g=0]
> [   34.115913] Index: 25 pgmask=4kb va=77ea4000 asid=fd
> [   34.115913]  [pa=18122000 c=0 d=0 v=0 g=0] [pa=00000000 c=0 d=0 v=0 g=0]
C = 0, pa = 18122000,  it is weird, 

+. pa is too high for 32bit SOC here;

+. C=0 is not a valid cache attribute;

I think this is "not" a PTE for memory, maybe a swap entry?

Could you print the PTE value, not the value in TLB?

tTLB value lost software PTE bits

> [   34.127559] Index: 26 pgmask=4kb va=c0096000 asid=fd
> [   34.127559]  [pa=0302f000 c=3 d=1 v=1 g=1] [pa=03008000 c=3 d=1 v=1 g=1]
> [   34.139205]
> [   34.140686] Code: 03e00008  00000000  24831000 <bc950000> bc950020 
> bc950040  bc950060  bc950080  bc9500a0
> [   34.150445]
> [   34.151987] ---[ end trace 30089d2c358ff363 ]---
> [   34.156614] Kernel panic - not syncing: Fatal exception
> [   34.161831] Rebooting in 10 seconds..
> 
> > 
> > I really have no idea of how the page_prot setting affecting the swap
> > handling.
> > 
> > > Thanks and best regards!
> > > 
> > > 
> > > >     Original Message
> > > > From: 周琰杰 (Zhou Yanjie)
> > > > Sent: 2021年4月16日星期五 16:48
> > > > To: tsbogend@alpha.franken.de
> > > > Cc: linux-mips@vger.kernel.org; linux-kernel@vger.kernel.org; akpm@linux-foundation.org; paul.burton@mips.com; paul@crapouillou.net; siyanteng@loongson.cn; huangpei@loongson.cn; ira.weiny@intel.com; yangtiezhu@loongson.cn; zhouyanjie@wanyeetech.com; jun.jiang@ingenic.com; dongsheng.qiu@ingenic.com; aric.pzqi@ingenic.com; rick.tyliu@ingenic.com; sernia.zhou@foxmail.com
> > > > Subject: [PATCH] Revert "MIPS: make userspace mapping young by default".
> > > > 
> > > > This reverts commit f685a533a7fab35c5d069dcd663f59c8e4171a75.
> > > > 
> > > > It cause kernel panic on Ingenic X1830, so let's revert it.
> > > > 
> > > > Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
> > > > ---
> > > > arch/mips/mm/cache.c | 31 ++++++++++++++-----------------
> > > > 1 file changed, 14 insertions(+), 17 deletions(-)
> > > > 
> > > > diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
> > > > index 7719d63..9cfd432 100644
> > > > --- a/arch/mips/mm/cache.c
> > > > +++ b/arch/mips/mm/cache.c
> > > > @@ -21,7 +21,6 @@
> > > > #include <asm/cpu.h>
> > > > #include <asm/cpu-features.h>
> > > > #include <asm/setup.h>
> > > > -#include <asm/pgtable.h>
> > > > 
> > > > /* Cache operations. */
> > > > void (*flush_cache_all)(void);
> > > > @@ -157,31 +156,29 @@ unsigned long _page_cachable_default;
> > > > EXPORT_SYMBOL(_page_cachable_default);
> > > > 
> > > > #define PM(p)	__pgprot(_page_cachable_default | (p))
> > > > -#define PVA(p)	PM(_PAGE_VALID | _PAGE_ACCESSED | (p))
> > > > 
> > > > static inline void setup_protection_map(void)
> > > > {
> > > > protection_map[0] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> > > > -	protection_map[1] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > -	protection_map[2] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> > > > -	protection_map[3] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > -	protection_map[4] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[5] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[6] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[7] = PVA(_PAGE_PRESENT);
> > > > +	protection_map[1] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > +	protection_map[2] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> > > > +	protection_map[3] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > +	protection_map[4] = PM(_PAGE_PRESENT);
> > > > +	protection_map[5] = PM(_PAGE_PRESENT);
> > > > +	protection_map[6] = PM(_PAGE_PRESENT);
> > > > +	protection_map[7] = PM(_PAGE_PRESENT);
> > > > 
> > > > protection_map[8] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
> > > > -	protection_map[9] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > -	protection_map[10] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE |
> > > > +	protection_map[9] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC);
> > > > +	protection_map[10] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE |
> > > > _PAGE_NO_READ);
> > > > -	protection_map[11] = PVA(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
> > > > -	protection_map[12] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[13] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[14] = PVA(_PAGE_PRESENT);
> > > > -	protection_map[15] = PVA(_PAGE_PRESENT);
> > > > +	protection_map[11] = PM(_PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
> > > > +	protection_map[12] = PM(_PAGE_PRESENT);
> > > > +	protection_map[13] = PM(_PAGE_PRESENT);
> > > > +	protection_map[14] = PM(_PAGE_PRESENT | _PAGE_WRITE);
> > > > +	protection_map[15] = PM(_PAGE_PRESENT | _PAGE_WRITE);
> > > > }
> > > > 
> > > > -#undef _PVA
> > > > #undef PM
> > > > 
> > > > void cpu_cache_init(void)