diff mbox series

[RFC,1/2] resource: Request IO port regions from children of ioport_resource

Message ID 1552582516-70855-2-git-send-email-john.garry@huawei.com
State New
Headers show
Series Fix system crash for accessing unmapped IO port regions | expand

Commit Message

John Garry March 14, 2019, 4:55 p.m. UTC 
Currently when we request an IO port region, the request is made directly
to the top resource, ioport_resource.

There is an issue here, in that drivers may request an IO port region even
if the IO port region has not even been mapped in (in pci_remap_iospace()).

This may lead to crashes when the PCI host has not enumerated prior to
accessing the IO port region, as below:

root@(none)$ insmod f71805f.ko
[   32.264016] Unable to handle kernel paging request at virtual address ffff7dfffee0002e
[   32.279936] Mem abort info:
[   32.285536]   ESR = 0x96000046
[   32.291657]   Exception class = DABT (current EL), IL = 32 bits
[   32.303542]   SET = 0, FnV = 0
[   32.309661]   EA = 0, S1PTW = 0
[   32.315957] Data abort info:
[   32.321728]   ISV = 0, ISS = 0x00000046
[   32.329420]   CM = 0, WnR = 1
[   32.335367] swapper pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
[   32.349174] [ffff7dfffee0002e] pgd=0000000001392003, pud=0000000001393003, pmd=0000000000000000
[   32.366652] Internal error: Oops: 96000046 [#1] PREEMPT SMP
[   32.377835] Modules linked in: f71805f(+)
[   32.385876] CPU: 4 PID: 2681 Comm: insmod Not tainted 5.0.0-00003-ga6247cc0f8f2 #52
[   32.401252] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018
[   32.419597] pstate: 80000005 (Nzcv daif -PAN -UAO)
[   32.429213] pc : logic_outb+0x54/0xb8
[   32.436556] lr : f71805f_find+0x2c/0x1b8 [f71805f]
[   32.446167] sp : ffff0000256bba90
[   32.452808] x29: ffff0000256bba90 x28: ffff000008b544d0
[   32.463468] x27: ffff0000256bbdf0 x26: 0000000000000100
[   32.474127] x25: 000000000000002c x24: ffff000011396000
[   32.484787] x23: ffff0000256bbb3e x22: ffff0000256bbb40
[   32.495446] x21: ffff000008b591b8 x20: 0000000000000087
[   32.506106] x19: 000000000000002e x18: ffffffffffffffff
[   32.516765] x17: 0000000000000000 x16: 0000000000000000
[   32.527424] x15: 0000000000000400 x14: 0000000000000400
[   32.538084] x13: 0000000000001832 x12: 0000000000000000
[   32.548743] x11: ffff801ffbf08ac0 x10: 0000801fead02000
[   32.559403] x9 : ffff801ffbffe840 x8 : 0000000000000001
[   32.570062] x7 : 0000000000210d00 x6 : 0000000000000000
[   32.580721] x5 : ffff801fb3eac380 x4 : ffff801ffbef4b20
[   32.591381] x3 : 0000000000ffbffe x2 : ffff0000256bbb40
[   32.602040] x1 : ffff7dfffee0002e x0 : ffff7dfffee00000
[   32.612701] Process insmod (pid: 2681, stack limit = 0x(____ptrval____))
[   32.626155] Call trace:
[   32.631050]  logic_outb+0x54/0xb8
[   32.637693]  f71805f_find+0x2c/0x1b8 [f71805f]
[   32.646607]  f71805f_init+0x38/0xe48 [f71805f]
[   32.655521]  do_one_initcall+0x5c/0x178
[   32.663212]  do_init_module+0x58/0x1b0
[   32.670728]  load_module+0x1dc8/0x2178
[   32.678243]  __se_sys_init_module+0x14c/0x1e8
[   32.686981]  __arm64_sys_init_module+0x18/0x20
[   32.695894]  el0_svc_common+0x60/0x100
[   32.703409]  el0_svc_handler+0x2c/0x80
[   32.710924]  el0_svc+0x8/0xc
[   32.716693] Code: d2bfdc00 f2cfbfe0 f2ffffe0 8b000021 (39000034)
[   32.728925] ---[ end trace ddb5e493ee686685 ]---
Segmentation fault
root@(none)$

This issue was originally reported in [1].

This patch changes the functionality of request_region() to request a
region of the direct children of the top ioport_resource.

In this, if the IO port region has not been mapped for a particular IO
region, a suitable child region will not exist, and, as such,
request_region() calls will fail.

A side note: there are many drivers in the kernel which fail to even call
request_region() prior to IO port accesses, and they also need to be fixed
(to call request_region() as appropriate).

[1] https://www.spinics.net/lists/linux-pci/msg49821.html

Signed-off-by: John Garry <john.garry@huawei.com>

---
 include/linux/ioport.h |  6 +++++-
 kernel/resource.c      | 19 +++++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

-- 
2.17.1

Comments

Guenter Roeck March 14, 2019, 5:12 p.m. UTC | #1 
On Fri, Mar 15, 2019 at 12:55:15AM +0800, John Garry wrote:
> Currently when we request an IO port region, the request is made directly

> to the top resource, ioport_resource.

> 

> There is an issue here, in that drivers may request an IO port region even

> if the IO port region has not even been mapped in (in pci_remap_iospace()).

> 

> This may lead to crashes when the PCI host has not enumerated prior to

> accessing the IO port region, as below:

> 

> root@(none)$ insmod f71805f.ko

> [   32.264016] Unable to handle kernel paging request at virtual address ffff7dfffee0002e

> [   32.279936] Mem abort info:

> [   32.285536]   ESR = 0x96000046

> [   32.291657]   Exception class = DABT (current EL), IL = 32 bits

> [   32.303542]   SET = 0, FnV = 0

> [   32.309661]   EA = 0, S1PTW = 0

> [   32.315957] Data abort info:

> [   32.321728]   ISV = 0, ISS = 0x00000046

> [   32.329420]   CM = 0, WnR = 1

> [   32.335367] swapper pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)

> [   32.349174] [ffff7dfffee0002e] pgd=0000000001392003, pud=0000000001393003, pmd=0000000000000000

> [   32.366652] Internal error: Oops: 96000046 [#1] PREEMPT SMP

> [   32.377835] Modules linked in: f71805f(+)

> [   32.385876] CPU: 4 PID: 2681 Comm: insmod Not tainted 5.0.0-00003-ga6247cc0f8f2 #52

> [   32.401252] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018

> [   32.419597] pstate: 80000005 (Nzcv daif -PAN -UAO)

> [   32.429213] pc : logic_outb+0x54/0xb8

> [   32.436556] lr : f71805f_find+0x2c/0x1b8 [f71805f]

> [   32.446167] sp : ffff0000256bba90

> [   32.452808] x29: ffff0000256bba90 x28: ffff000008b544d0

> [   32.463468] x27: ffff0000256bbdf0 x26: 0000000000000100

> [   32.474127] x25: 000000000000002c x24: ffff000011396000

> [   32.484787] x23: ffff0000256bbb3e x22: ffff0000256bbb40

> [   32.495446] x21: ffff000008b591b8 x20: 0000000000000087

> [   32.506106] x19: 000000000000002e x18: ffffffffffffffff

> [   32.516765] x17: 0000000000000000 x16: 0000000000000000

> [   32.527424] x15: 0000000000000400 x14: 0000000000000400

> [   32.538084] x13: 0000000000001832 x12: 0000000000000000

> [   32.548743] x11: ffff801ffbf08ac0 x10: 0000801fead02000

> [   32.559403] x9 : ffff801ffbffe840 x8 : 0000000000000001

> [   32.570062] x7 : 0000000000210d00 x6 : 0000000000000000

> [   32.580721] x5 : ffff801fb3eac380 x4 : ffff801ffbef4b20

> [   32.591381] x3 : 0000000000ffbffe x2 : ffff0000256bbb40

> [   32.602040] x1 : ffff7dfffee0002e x0 : ffff7dfffee00000

> [   32.612701] Process insmod (pid: 2681, stack limit = 0x(____ptrval____))

> [   32.626155] Call trace:

> [   32.631050]  logic_outb+0x54/0xb8

> [   32.637693]  f71805f_find+0x2c/0x1b8 [f71805f]

> [   32.646607]  f71805f_init+0x38/0xe48 [f71805f]

> [   32.655521]  do_one_initcall+0x5c/0x178

> [   32.663212]  do_init_module+0x58/0x1b0

> [   32.670728]  load_module+0x1dc8/0x2178

> [   32.678243]  __se_sys_init_module+0x14c/0x1e8

> [   32.686981]  __arm64_sys_init_module+0x18/0x20

> [   32.695894]  el0_svc_common+0x60/0x100

> [   32.703409]  el0_svc_handler+0x2c/0x80

> [   32.710924]  el0_svc+0x8/0xc

> [   32.716693] Code: d2bfdc00 f2cfbfe0 f2ffffe0 8b000021 (39000034)

> [   32.728925] ---[ end trace ddb5e493ee686685 ]---

> Segmentation fault

> root@(none)$

> 

> This issue was originally reported in [1].

> 

> This patch changes the functionality of request_region() to request a

> region of the direct children of the top ioport_resource.

> 

> In this, if the IO port region has not been mapped for a particular IO

> region, a suitable child region will not exist, and, as such,

> request_region() calls will fail.

> 

> A side note: there are many drivers in the kernel which fail to even call

> request_region() prior to IO port accesses, and they also need to be fixed

> (to call request_region() as appropriate).

> 


Isn't that orthogonal to this problem ?

> [1] https://www.spinics.net/lists/linux-pci/msg49821.html

> 

> Signed-off-by: John Garry <john.garry@huawei.com>

> ---

>  include/linux/ioport.h |  6 +++++-

>  kernel/resource.c      | 19 +++++++++++++++++++

>  2 files changed, 24 insertions(+), 1 deletion(-)

> 

> diff --git a/include/linux/ioport.h b/include/linux/ioport.h

> index da0ebaec25f0..cf40e1ed8211 100644

> --- a/include/linux/ioport.h

> +++ b/include/linux/ioport.h

> @@ -217,7 +217,7 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2)

>  

>  

>  /* Convenience shorthand with allocation */

> -#define request_region(start,n,name)		__request_region(&ioport_resource, (start), (n), (name), 0)

> +#define request_region(start,n,name)		__request_region_from_children(&ioport_resource, (start), (n), (name), 0)

>  #define request_muxed_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)

>  #define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)

>  #define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)


I can't comment on the merits of the patch (though I am a bit concerned
about its impact and potential source of regressions), but I don't really
understand why it would only apply to request_region() and not to
request_muxed_region(). Is this an oversight or on purpose ?

Guenter
John Garry March 14, 2019, 5:39 p.m. UTC | #2 
On 14/03/2019 17:12, Guenter Roeck wrote:
> On Fri, Mar 15, 2019 at 12:55:15AM +0800, John Garry wrote:

>> Currently when we request an IO port region, the request is made directly

>> to the top resource, ioport_resource.

>>

>> There is an issue here, in that drivers may request an IO port region even

>> if the IO port region has not even been mapped in (in pci_remap_iospace()).

>>

>> This may lead to crashes when the PCI host has not enumerated prior to

>> accessing the IO port region, as below:

>>

>> root@(none)$ insmod f71805f.ko

>> [   32.264016] Unable to handle kernel paging request at virtual address ffff7dfffee0002e

>> [   32.279936] Mem abort info:

>> [   32.285536]   ESR = 0x96000046

>> [   32.291657]   Exception class = DABT (current EL), IL = 32 bits

>> [   32.303542]   SET = 0, FnV = 0

>> [   32.309661]   EA = 0, S1PTW = 0

>> [   32.315957] Data abort info:

>> [   32.321728]   ISV = 0, ISS = 0x00000046

>> [   32.329420]   CM = 0, WnR = 1

>> [   32.335367] swapper pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)

>> [   32.349174] [ffff7dfffee0002e] pgd=0000000001392003, pud=0000000001393003, pmd=0000000000000000

>> [   32.366652] Internal error: Oops: 96000046 [#1] PREEMPT SMP

>> [   32.377835] Modules linked in: f71805f(+)

>> [   32.385876] CPU: 4 PID: 2681 Comm: insmod Not tainted 5.0.0-00003-ga6247cc0f8f2 #52

>> [   32.401252] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018

>> [   32.419597] pstate: 80000005 (Nzcv daif -PAN -UAO)

>> [   32.429213] pc : logic_outb+0x54/0xb8

>> [   32.436556] lr : f71805f_find+0x2c/0x1b8 [f71805f]

>> [   32.446167] sp : ffff0000256bba90

>> [   32.452808] x29: ffff0000256bba90 x28: ffff000008b544d0

>> [   32.463468] x27: ffff0000256bbdf0 x26: 0000000000000100

>> [   32.474127] x25: 000000000000002c x24: ffff000011396000

>> [   32.484787] x23: ffff0000256bbb3e x22: ffff0000256bbb40

>> [   32.495446] x21: ffff000008b591b8 x20: 0000000000000087

>> [   32.506106] x19: 000000000000002e x18: ffffffffffffffff

>> [   32.516765] x17: 0000000000000000 x16: 0000000000000000

>> [   32.527424] x15: 0000000000000400 x14: 0000000000000400

>> [   32.538084] x13: 0000000000001832 x12: 0000000000000000

>> [   32.548743] x11: ffff801ffbf08ac0 x10: 0000801fead02000

>> [   32.559403] x9 : ffff801ffbffe840 x8 : 0000000000000001

>> [   32.570062] x7 : 0000000000210d00 x6 : 0000000000000000

>> [   32.580721] x5 : ffff801fb3eac380 x4 : ffff801ffbef4b20

>> [   32.591381] x3 : 0000000000ffbffe x2 : ffff0000256bbb40

>> [   32.602040] x1 : ffff7dfffee0002e x0 : ffff7dfffee00000

>> [   32.612701] Process insmod (pid: 2681, stack limit = 0x(____ptrval____))

>> [   32.626155] Call trace:

>> [   32.631050]  logic_outb+0x54/0xb8

>> [   32.637693]  f71805f_find+0x2c/0x1b8 [f71805f]

>> [   32.646607]  f71805f_init+0x38/0xe48 [f71805f]

>> [   32.655521]  do_one_initcall+0x5c/0x178

>> [   32.663212]  do_init_module+0x58/0x1b0

>> [   32.670728]  load_module+0x1dc8/0x2178

>> [   32.678243]  __se_sys_init_module+0x14c/0x1e8

>> [   32.686981]  __arm64_sys_init_module+0x18/0x20

>> [   32.695894]  el0_svc_common+0x60/0x100

>> [   32.703409]  el0_svc_handler+0x2c/0x80

>> [   32.710924]  el0_svc+0x8/0xc

>> [   32.716693] Code: d2bfdc00 f2cfbfe0 f2ffffe0 8b000021 (39000034)

>> [   32.728925] ---[ end trace ddb5e493ee686685 ]---

>> Segmentation fault

>> root@(none)$

>>

>> This issue was originally reported in [1].

>>

>> This patch changes the functionality of request_region() to request a

>> region of the direct children of the top ioport_resource.

>>

>> In this, if the IO port region has not been mapped for a particular IO

>> region, a suitable child region will not exist, and, as such,

>> request_region() calls will fail.

>>

>> A side note: there are many drivers in the kernel which fail to even call

>> request_region() prior to IO port accesses, and they also need to be fixed

>> (to call request_region() as appropriate).

>>


Hi Guenter,

>

> Isn't that orthogonal to this problem ?


Yes, it is really. I only added the f71805f driver fixup to illustrate 
the problem in resource.c and the potential system crash, and how this 
patch would fix it.

>

>> [1] https://www.spinics.net/lists/linux-pci/msg49821.html

>>

>> Signed-off-by: John Garry <john.garry@huawei.com>

>> ---

>>  include/linux/ioport.h |  6 +++++-

>>  kernel/resource.c      | 19 +++++++++++++++++++

>>  2 files changed, 24 insertions(+), 1 deletion(-)

>>

>> diff --git a/include/linux/ioport.h b/include/linux/ioport.h

>> index da0ebaec25f0..cf40e1ed8211 100644

>> --- a/include/linux/ioport.h

>> +++ b/include/linux/ioport.h

>> @@ -217,7 +217,7 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2)

>>

>>

>>  /* Convenience shorthand with allocation */

>> -#define request_region(start,n,name)		__request_region(&ioport_resource, (start), (n), (name), 0)

>> +#define request_region(start,n,name)		__request_region_from_children(&ioport_resource, (start), (n), (name), 0)

>>  #define request_muxed_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)

>>  #define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)

>>  #define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)

>

> I can't comment on the merits of the patch (though I am a bit concerned

> about its impact and potential source of regressions),but I don't really

> understand why it would only apply to request_region() and not to

> request_muxed_region(). Is this an oversight or on purpose ?


It's an oversight, which would be fixed.

Thanks,
John

>

> Guenter

>

> .

>
diff mbox series

Patch

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index da0ebaec25f0..cf40e1ed8211 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -217,7 +217,7 @@  static inline bool resource_contains(struct resource *r1, struct resource *r2)
 
 
 /* Convenience shorthand with allocation */
-#define request_region(start,n,name)		__request_region(&ioport_resource, (start), (n), (name), 0)
+#define request_region(start,n,name)		__request_region_from_children(&ioport_resource, (start), (n), (name), 0)
 #define request_muxed_region(start,n,name)	__request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED)
 #define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl)
 #define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0)
@@ -230,6 +230,10 @@  extern struct resource * __request_region(struct resource *,
 					resource_size_t n,
 					const char *name, int flags);
 
+extern struct resource * __request_region_from_children(struct resource *,
+							resource_size_t start,
+							resource_size_t n,
+							const char *name, int flags);
 /* Compatibility cruft */
 #define release_region(start,n)	__release_region(&ioport_resource, (start), (n))
 #define release_mem_region(start,n)	__release_region(&iomem_resource, (start), (n))
diff --git a/kernel/resource.c b/kernel/resource.c
index 915c02e8e5dd..4a4656bd6051 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1098,6 +1098,25 @@  resource_size_t resource_alignment(struct resource *res)
 
 static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait);
 
+struct resource * __request_region_from_children(struct resource *parent,
+						 resource_size_t start,
+						 resource_size_t n,
+						 const char *name, int flags)
+{
+	struct resource *child;
+
+	/* TODO - add locking */
+	for (child = parent->child; child; child = child->sibling) {
+		struct resource *res = __request_region(child, start, n, name, flags);
+
+		if (res)
+			return res;
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(__request_region_from_children);
+
 /**
  * __request_region - create a new busy resource region
  * @parent: parent resource descriptor