On Wed, Jun 30, 2021 at 10:12:11AM +0300, Mike Rapoport wrote:

From: Mike Rapoport <redacted>

When unused memory map is freed the preserved part of the memory map is
extended to match pageblock boundaries because lots of core mm
functionality relies on homogeneity of the memory map within pageblock
boundaries.

Since pfn_valid() is used to check whether there is a valid memory map
entry for a PFN, make it return true also for PFNs that have memory map
entries even if there is no actual memory populated there.

Signed-off-by: Mike Rapoport <redacted>
Tested-by: Kefeng Wang <redacted>

With this patch in place, the romulus-bmc emulation in qemu gets the
following traceback:

[    2.863406] WARNING: CPU: 0 PID: 1 at arch/arm/mm/ioremap.c:287 __arm_ioremap_pfn_caller+0xf0/0x1dc
[    2.864812] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-09882-ga180bd1d7e16 #1
[    2.865263] Hardware name: Generic DT based system
[    2.865711] Backtrace: 
[    2.866063] [<80b07e58>] (dump_backtrace) from [<80b080ac>] (show_stack+0x20/0x24)
[    2.866633]  r7:00000009 r6:0000011f r5:60000153 r4:80ddd1c0
[    2.866922] [<80b0808c>] (show_stack) from [<80b18df0>] (dump_stack_lvl+0x58/0x74)
[    2.867117] [<80b18d98>] (dump_stack_lvl) from [<80b18e20>] (dump_stack+0x14/0x1c)
[    2.867309]  r5:80118cac r4:80dc6774
[    2.867404] [<80b18e0c>] (dump_stack) from [<80122fcc>] (__warn+0xe4/0x150)
[    2.867583] [<80122ee8>] (__warn) from [<80b08850>] (warn_slowpath_fmt+0x88/0xc0)
[    2.867774]  r7:0000011f r6:80dc6774 r5:00000000 r4:814c4000
[    2.867917] [<80b087cc>] (warn_slowpath_fmt) from [<80118cac>] (__arm_ioremap_pfn_caller+0xf0/0x1dc)
[    2.868158]  r9:00000001 r8:9ef00000 r7:80e8b0d4 r6:0009ef00 r5:00000000 r4:00100000
[    2.868346] [<80118bbc>] (__arm_ioremap_pfn_caller) from [<80118df8>] (__arm_ioremap_caller+0x60/0x68)
[    2.868581]  r9:9ef00000 r8:821b6dc0 r7:00100000 r6:00000000 r5:815d1010 r4:80118d98
[    2.868761] [<80118d98>] (__arm_ioremap_caller) from [<80118fcc>] (ioremap+0x28/0x30)
[    2.868958] [<80118fa4>] (ioremap) from [<8062871c>] (__devm_ioremap_resource+0x154/0x1c8)
[    2.869169]  r5:815d1010 r4:814c5d2c
[    2.869263] [<806285c8>] (__devm_ioremap_resource) from [<8062899c>] (devm_ioremap_resource+0x14/0x18)
[    2.869495]  r9:9e9f57a0 r8:814c4000 r7:815d1000 r6:815d1010 r5:8177c078 r4:815cf400
[    2.869676] [<80628988>] (devm_ioremap_resource) from [<8091c6e4>] (fsi_master_acf_probe+0x1a8/0x5d8)
[    2.869909] [<8091c53c>] (fsi_master_acf_probe) from [<80723dbc>] (platform_probe+0x68/0xc8)
[    2.870124]  r9:80e9dadc r8:00000000 r7:815d1010 r6:810c1000 r5:815d1010 r4:00000000
[    2.870306] [<80723d54>] (platform_probe) from [<80721208>] (really_probe+0x1cc/0x470)
[    2.870512]  r7:815d1010 r6:810c1000 r5:00000000 r4:815d1010
[    2.870651] [<8072103c>] (really_probe) from [<807215cc>] (__driver_probe_device+0x120/0x1fc)
[    2.870872]  r7:815d1010 r6:810c1000 r5:810c1000 r4:815d1010
[    2.871013] [<807214ac>] (__driver_probe_device) from [<807216e8>] (driver_probe_device+0x40/0xd8)
[    2.871244]  r9:80e9dadc r8:00000000 r7:815d1010 r6:810c1000 r5:812feaa0 r4:812fe994
[    2.871428] [<807216a8>] (driver_probe_device) from [<80721a58>] (__driver_attach+0xa8/0x1d4)
[    2.871647]  r9:80e9dadc r8:00000000 r7:00000000 r6:810c1000 r5:815d1054 r4:815d1010
[    2.871830] [<807219b0>] (__driver_attach) from [<8071ee8c>] (bus_for_each_dev+0x88/0xc8)
[    2.872040]  r7:00000000 r6:814c4000 r5:807219b0 r4:810c1000
[    2.872194] [<8071ee04>] (bus_for_each_dev) from [<80722208>] (driver_attach+0x28/0x30)
[    2.872418]  r7:810a2aa0 r6:00000000 r5:821b6000 r4:810c1000
[    2.872570] [<807221e0>] (driver_attach) from [<8071f80c>] (bus_add_driver+0x114/0x200)
[    2.872788] [<8071f6f8>] (bus_add_driver) from [<80722ec4>] (driver_register+0x98/0x128)
[    2.873011]  r7:81011d0c r6:814c4000 r5:00000000 r4:810c1000
[    2.873167] [<80722e2c>] (driver_register) from [<80725240>] (__platform_driver_register+0x2c/0x34)
[    2.873408]  r5:814dcb80 r4:80f2a764
[    2.873513] [<80725214>] (__platform_driver_register) from [<80f2a784>] (fsi_master_acf_init+0x20/0x28)
[    2.873766] [<80f2a764>] (fsi_master_acf_init) from [<80f014a8>] (do_one_initcall+0x108/0x290)
[    2.874007] [<80f013a0>] (do_one_initcall) from [<80f01840>] (kernel_init_freeable+0x1ac/0x230)
[    2.874248]  r9:80e9dadc r8:80f3987c r7:80f3985c r6:00000007 r5:814dcb80 r4:80f627a4
[    2.874456] [<80f01694>] (kernel_init_freeable) from [<80b19f44>] (kernel_init+0x20/0x138)
[    2.874691]  r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80b19f24
[    2.874894]  r4:00000000
[    2.874977] [<80b19f24>] (kernel_init) from [<80100170>] (ret_from_fork+0x14/0x24)
[    2.875231] Exception stack(0x814c5fb0 to 0x814c5ff8)
[    2.875535] 5fa0:                                     00000000 00000000 00000000 00000000
[    2.875849] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    2.876133] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    2.876363]  r5:80b19f24 r4:00000000
[    2.876683] ---[ end trace b2f74b8536829970 ]---
[    2.876911] fsi-master-acf gpio-fsi: ioremap failed for resource [mem 0x9ef00000-0x9effffff]
[    2.877492] fsi-master-acf gpio-fsi: Error -12 mapping coldfire memory
[    2.877689] fsi-master-acf: probe of gpio-fsi failed with error -12

Reverting it fixes the problem. Also, the ioremap failure is no longer seen
after reverting this patch.

Guenter

---
bisect log:

# bad: [a180bd1d7e16173d965b263c5a536aa40afa2a2a] iov_iter: remove uaccess_kernel() warning from iov_iter_init()
# good: [303392fd5c160822bf778270b28ec5ea50cab2b4] Merge tag 'leds-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/pavel/linux-leds
git bisect start 'HEAD' '303392fd5c16'
# good: [2bb919b62f6e5959552a90a399d09d683afa3d1d] Merge tag 's390-5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
git bisect good 2bb919b62f6e5959552a90a399d09d683afa3d1d
# good: [5390473ec1697b71af0e9d63ef7aaa7ecd27e2c9] rcu: Don't penalize priority boosting when there is nothing to boost
git bisect good 5390473ec1697b71af0e9d63ef7aaa7ecd27e2c9
# good: [641faf1b9064c270a476a424e60063bb05df3ee9] Merge branches 'bitmaprange.2021.05.10c', 'doc.2021.05.10c', 'fixes.2021.05.13a', 'kvfree_rcu.2021.05.10c', 'mmdumpobj.2021.05.10c', 'nocb.2021.05.12a', 'srcu.2021.05.12a', 'tasks.2021.05.18a' and 'torture.2021.05.10c' into HEAD
git bisect good 641faf1b9064c270a476a424e60063bb05df3ee9
# good: [b930226f3db870cfb683c2744aeb0d29deb4cddc] kcsan: Document "value changed" line
git bisect good b930226f3db870cfb683c2744aeb0d29deb4cddc
# bad: [a412897fb546fbb291095be576165ce757eff70b] Merge tag 'memblock-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
git bisect bad a412897fb546fbb291095be576165ce757eff70b
# good: [f921f53e089a12a192808ac4319f28727b35dc0f] memblock: align freed memory map on pageblock boundaries with SPARSEMEM
git bisect good f921f53e089a12a192808ac4319f28727b35dc0f
# bad: [a4d5613c4dc6d413e0733e37db9d116a2a36b9f3] arm: extend pfn_valid to take into account freed memory map alignment
git bisect bad a4d5613c4dc6d413e0733e37db9d116a2a36b9f3
# good: [023accf5cdc1e504a9b04187ec23ff156fe53d90] memblock: ensure there is no overflow in memblock_overlaps_region()
git bisect good 023accf5cdc1e504a9b04187ec23ff156fe53d90
# first bad commit: [a4d5613c4dc6d413e0733e37db9d116a2a36b9f3] arm: extend pfn_valid to take into account freed memory map alignment

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel