From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Fixes: fdb64822443e ("perf/x86: Add Intel Tiger Lake uncore support") Reported-by: Ammy Yi ammy.yi@intel.com Tested-by: Ammy Yi ammy.yi@intel.com Tested-by: Chao Qin chao.qin@intel.com Signed-off-by: Kan Liang kan.liang@linux.intel.com Cc: stable@vger.kernel.org --- arch/x86/events/intel/uncore_snb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c index 3de1065..1038e9f 100644 --- a/arch/x86/events/intel/uncore_snb.c +++ b/arch/x86/events/intel/uncore_snb.c @@ -1085,6 +1085,7 @@ static struct pci_dev *tgl_uncore_get_mc_dev(void) }
#define TGL_UNCORE_MMIO_IMC_MEM_OFFSET 0x10000 +#define TGL_UNCORE_PCI_IMC_MAP_SIZE 0xe000
static void tgl_uncore_imc_freerunning_init_box(struct intel_uncore_box *box) { @@ -1112,7 +1113,7 @@ static void tgl_uncore_imc_freerunning_init_box(struct intel_uncore_box *box) addr |= ((resource_size_t)mch_bar << 32); #endif
- box->io_addr = ioremap(addr, SNB_UNCORE_PCI_IMC_MAP_SIZE); + box->io_addr = ioremap(addr, TGL_UNCORE_PCI_IMC_MAP_SIZE); }
static struct intel_uncore_ops tgl_uncore_imc_freerunning_ops = {
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On 5/27/2020 8:59 AM, David Laight wrote:
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
Thanks for the review.
I agree that we should add a check before mapping the area to prevent the issue happens again.
I think the check should be a generic check for all platforms which try to map an area, not just for TGL. I will submit a separate patch for the check.
Thanks, Kan
David
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
From: Liang, Kan
Sent: 27 May 2020 15:47 On 5/27/2020 8:59 AM, David Laight wrote:
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
Thanks for the review.
I agree that we should add a check before mapping the area to prevent the issue happens again.
I think the check should be a generic check for all platforms which try to map an area, not just for TGL. I will submit a separate patch for the check.
You need a check that the actual access is withing the mapped area. So instead of getting an OOPS you get a error.
This is after you've mapped it.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On 5/27/2020 10:51 AM, David Laight wrote:
From: Liang, Kan
Sent: 27 May 2020 15:47 On 5/27/2020 8:59 AM, David Laight wrote:
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
Thanks for the review.
I agree that we should add a check before mapping the area to prevent the issue happens again.
I think the check should be a generic check for all platforms which try to map an area, not just for TGL. I will submit a separate patch for the check.
You need a check that the actual access is withing the mapped area. So instead of getting an OOPS you get a error.
This is after you've mapped it.
Sure. Will add a WARN_ONCE() before the actual access.
Thanks, Kan
David
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
From: Liang, Kan
Sent: 27 May 2020 16:01 On 5/27/2020 10:51 AM, David Laight wrote:
From: Liang, Kan
Sent: 27 May 2020 15:47 On 5/27/2020 8:59 AM, David Laight wrote:
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
Thanks for the review.
I agree that we should add a check before mapping the area to prevent the issue happens again.
I think the check should be a generic check for all platforms which try to map an area, not just for TGL. I will submit a separate patch for the check.
You need a check that the actual access is withing the mapped area. So instead of getting an OOPS you get a error.
This is after you've mapped it.
Sure. Will add a WARN_ONCE() before the actual access.
No that will still panic some systems. pr_warn() is all you need.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On 5/27/2020 11:17 AM, David Laight wrote:
From: Liang, Kan
Sent: 27 May 2020 16:01 On 5/27/2020 10:51 AM, David Laight wrote:
From: Liang, Kan
Sent: 27 May 2020 15:47 On 5/27/2020 8:59 AM, David Laight wrote:
From: kan.liang@linux.intel.com
Sent: 27 May 2020 13:31
From: Kan Liang kan.liang@linux.intel.com
When counting IMC uncore events on some TGL machines, an oops will be triggered. [ 393.101262] BUG: unable to handle page fault for address: ffffb45200e15858 [ 393.101269] #PF: supervisor read access in kernel mode [ 393.101271] #PF: error_code(0x0000) - not-present page
Current perf uncore driver still use the IMC MAP SIZE inherited from SNB, which is 0x6000. However, the offset of IMC uncore counters for some TGL machines is larger than 0x6000, e.g. 0xd8a0.
Enlarge the IMC MAP SIZE for TGL to 0xe000.
Replacing one 'random' constant with a different one doesn't seem like a proper fix.
Surely the actual bounds of the 'memory' area are properly defined somewhere. Or at least should come from a table.
You also need to verify that the offsets are within the mapped area. An unexpected offset shouldn't try to access an invalid address.
Thanks for the review.
I agree that we should add a check before mapping the area to prevent the issue happens again.
I think the check should be a generic check for all platforms which try to map an area, not just for TGL. I will submit a separate patch for the check.
You need a check that the actual access is withing the mapped area. So instead of getting an OOPS you get a error.
This is after you've mapped it.
Sure. Will add a WARN_ONCE() before the actual access.
No that will still panic some systems. pr_warn() is all you need.
If we print a warning for each access, there will be too many warnings. I think I will use pr_warn_once instead.
Thanks, Kan
linux-stable-mirror@lists.linaro.org
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David Laight -
kan.liang＠linux.intel.com -
Liang, Kan