Re: [PATCH v3 4/4] arm: extend pfn_valid to take into account freed memory map alignment
From: Guenter Roeck
Date: Mon Jul 05 2021 - 10:55:32 EST
On 7/5/21 12:23 AM, Mike Rapoport wrote:
Hi Guenter,
On Sun, Jul 04, 2021 at 09:22:36PM -0700, Guenter Roeck wrote:
On Wed, Jun 30, 2021 at 10:12:11AM +0300, Mike Rapoport wrote:
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
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 <rppt@xxxxxxxxxxxxx>
Tested-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
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
...
[ 2.876683] ---[ 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.
I believe this should fix it:
Yes, it does.
From e2213b7e804daf0d31d47502379916f0542398bb Mon Sep 17 00:00:00 2001
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Date: Mon, 5 Jul 2021 08:43:10 +0300
Subject: [PATCH] arm: ioremap: don't abuse pfn_valid() to check if pfn is in RAM
The semantics of pfn_valid() is to check presence of the memory map for a
PFN and not whether a PFN is in RAM. The memory map may be present for a
hole in the physical memory and if such hole corresponds to an MMIO range,
__arm_ioremap_pfn_caller() will produce a WARN() and fail:
[ 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
Use memblock_is_map_memory() instead of pfn_valid() to check if a PFN is in
RAM or not.
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Tested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Thanks!
Guenter
---
arch/arm/mm/ioremap.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index 000e8210000b..80fb5a4a5c05 100644
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -27,6 +27,7 @@
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/sizes.h>
+#include <linux/memblock.h>
#include <asm/cp15.h>
#include <asm/cputype.h>
@@ -284,7 +285,8 @@ static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
* Don't allow RAM to be mapped with mismatched attributes - this
* causes problems with ARMv6+
*/
- if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
+ if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
+ mtype != MT_MEMORY_RW))
return NULL;
area = get_vm_area_caller(size, VM_IOREMAP, caller);