pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid().
Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Cc: Dave Hansen dave@sr71.net Cc: David Airlie airlied@linux.ie Reported-by: Julian Margetson runaway@candw.ms Reported-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Dan Williams dan.j.williams@intel.com --- mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 30991f83d0bf..93ce37989471 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP * without pte special, it would there be refcounted as a normal page. */ - if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) { + if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) { struct page *page;
- page = pfn_t_to_page(pfn); + /* + * At this point we are committed to insert_page() + * regardless of whether the caller specified flags that + * result in pfn_t_has_page() == false. + */ + page = pfn_to_page(pfn_t_to_pfn(pfn)); return insert_page(vma, addr, page, vma->vm_page_prot); } return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
On 1/26/2016 2:37 PM, Dan Williams wrote:
pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid().
Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Cc: Dave Hansen dave@sr71.net Cc: David Airlie airlied@linux.ie Reported-by: Julian Margetson runaway@candw.ms Reported-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Dan Williams dan.j.williams@intel.com
mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 30991f83d0bf..93ce37989471 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP * without pte special, it would there be refcounted as a normal page. */
- if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) {
- if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) { struct page *page;
page = pfn_t_to_page(pfn);
/** At this point we are committed to insert_page()* regardless of whether the caller specified flags that* result in pfn_t_has_page() == false.*/page = pfn_to_page(pfn_t_to_pfn(pfn));
[ 16.503323] systemd[1]: Mounting FUSE Control File System... [ 42.703092] Oops: Machine check, sig: 7 [#1] [ 42.707624] PREEMPT Canyonlands [ 42.710959] Modules linked in: [ 42.714201] CPU: 0 PID: 553 Comm: Xorg Not tainted 4.5.0-rc1-Sam460ex #1 [ 42.721283] task: ee1e45c0 ti: ecd46000 task.ti: ecd46000 [ 42.726983] NIP: 1fed2480 LR: 1fed2404 CTR: 1fed24d0 [ 42.732227] REGS: ecd47f10 TRAP: 0214 Not tainted (4.5.0-rc1-Sam460ex) [ 42.739395] MSR: 0002d000 <CE,EE,PR,ME> CR: 28004262 XER: 00000000 [ 42.746244] GPR00: 1f396134 bfcb0970 b77fc6f0 b6fbeffc b67d5008 00000780 00000004 00000000 GPR08: 00000000 b6fbeffc 00000000 bfcb0920 1fed2404 2076dff4 00000000 00000780 GPR16: 00000000 00000020 00000000 00000000 00001e00 209be650 00000438 b67d5008 GPR24: 00000780 bfcb09c8 209a8728 b6fbf000 b6fbf000 b67d5008 1ffdaff4 00001e00 [ 42.778096] NIP [1fed2480] 0x1fed2480 [ 42.781967] LR [1fed2404] 0x1fed2404 [ 42.785741] Call Trace: [ 42.943688] ---[ end trace 5d20a91d2d30d9d6 ]--- [ 42.948311] [ 46.641774] Machine check in kernel mode. [ 46.645805] Data Write PLB Error [ 46.649031] Machine Check exception is imprecise [ 46.653658] Vector: 214 at [eccfbf10] [ 46.657408] pc: 1ffa9480 [ 46.660325] lr: 1ffa9404 [ 46.663241] sp: bf9252b0 [ 46.666123] msr: 2d000 [ 46.668746] current = 0xee1e73c0 [ 46.672149] pid = 663, comm = Xorg [ 46.676074] Linux version 4.5.0-rc1-Sam460ex (root@julian-VirtualBox) (gcc version 4.8.2 (Ubuntu 4.8.2-16ubuntu3) ) #1 PREEMPT Tue Jan 26 15:40:11 AST 2016 [ 46.690001] enter ? for help [ 46.692886] mon> <no input ...> [ 48.696175] Oops: Machine check, sig: 7 [#2] [ 48.700706] PREEMPT Canyonlands [ 48.704049] Modules linked in: [ 48.707292] CPU: 0 PID: 663 Comm: Xorg Tainted: G D 4.5.0-rc1-Sam460ex #1 [ 48.715657] task: ee1e73c0 ti: eccfa000 task.ti: eccfa000 [ 48.721359] NIP: 1ffa9480 LR: 1ffa9404 CTR: 1ffa94d0 [ 48.726602] REGS: eccfbf10 TRAP: 0214 Tainted: G D (4.5.0-rc1-Sam460ex) [ 48.735055] MSR: 0002d000 <CE,EE,PR,ME> CR: 28004262 XER: 00000000 [ 48.741913] GPR00: 1f46d134 bf9252b0 b78b46f0 b7076ffc b688d008 00000780 00000004 00000000 GPR08: 00000000 b7076ffc 00000000 bf925260 1ffa9404 20844ff4 00000000 00000780 GPR16: 00000000 00000020 00000000 00000000 00001e00 20a7e638 00000438 b688d008 GPR24: 00000780 bf925308 20a68748 b7077000 b7077000 b688d008 200b1ff4 00001e00 [ 48.773765] NIP [1ffa9480] 0x1ffa9480 [ 48.777634] LR [1ffa9404] 0x1ffa9404 [ 48.781409] Call Trace: [ 48.783993] ---[ end trace 5d20a91d2d30d9d7 ]--- [ 48.788614] [ 51.289144] Machine check in kernel mode. [ 51.293175] Data Write PLB Error [ 51.296401] Machine Check exception is imprecise [ 51.301028] Vector: 214 at [ee225f10] [ 51.304778] pc: 1fc2e480 [ 51.307694] lr: 1fc2e404 [ 51.310612] sp: bfbd0390 [ 51.313493] msr: 2f900 [ 51.316115] current = 0xecce2840 [ 51.319519] pid = 680, comm = Xorg [ 51.323444] Linux version 4.5.0-rc1-Sam460ex (root@julian-VirtualBox) (gcc version 4.8.2 (Ubuntu 4.8.2-16ubuntu3) ) #1 PREEMPT Tue Jan 26 15:40:11 AST 2016 [ 51.337370] enter ? for help [ 51.340256] mon> <no input ...> [ 53.343544] Oops: Machine check, sig: 7 [#3] [ 53.348067] PREEMPT Canyonlands [ 53.351411] Modules linked in: [ 53.354653] CPU: 0 PID: 680 Comm: Xorg Tainted: G D 4.5.0-rc1-Sam460ex #1 [ 53.363019] task: ecce2840 ti: ee224000 task.ti: ee224000 [ 53.368720] NIP: 1fc2e480 LR: 1fc2e404 CTR: 1fc2e4d0 [ 53.373963] REGS: ee225f10 TRAP: 0214 Tainted: G D (4.5.0-rc1-Sam460ex) [ 53.382415] MSR: 0002f900 <CE,EE,PR,FP,ME> CR: 28004262 XER: 00000000 [ 53.389560] GPR00: 1f0f2134 bfbd0390 b7fad6f0 b776fffc b6f86008 00000780 00000004 00000000 GPR08: 00000000 b776fffc 00000000 bfbd0340 1fc2e404 204c9ff4 00000000 00000780 GPR16: 00000000 00000020 00000000 00000000 00001e00 206f7650 00000438 b6f86008 GPR24: 00000780 bfbd03e8 206e1760 b7770000 b7770000 b6f86008 1fd36ff4 00001e00 [ 53.421412] NIP [1fc2e480] 0x1fc2e480 [ 53.425283] LR [1fc2e404] 0x1fc2e404 [ 53.429057] Call Trace: [ 53.431641] ---[ end trace 5d20a91d2d30d9d8 ]--- [ 53.436261] [ 56.443200] Machine check in kernel mode. [ 56.447237] Data Write PLB Error [ 56.450463] Machine Check exception is imprecise [ 56.455091] Vector: 214 at [ecc07f10] [ 56.458841] pc: 1fa8a484 [ 56.461757] lr: 1fa8a404 [ 56.464674] sp: bffd7a20 [ 56.467556] msr: 2f900 [ 56.470178] current = 0xeced1140 [ 56.473581] pid = 693, comm = Xorg [ 56.477506] Linux version 4.5.0-rc1-Sam460ex (root@julian-VirtualBox) (gcc version 4.8.2 (Ubuntu 4.8.2-16ubuntu3) ) #1 PREEMPT Tue Jan 26 15:40:11 AST 2016 [ 56.491432] enter ? for help [ 56.494310] mon> <no input ...>
On Tue, Jan 26, 2016 at 11:46 AM, Julian Margetson runaway@candw.ms wrote:
On 1/26/2016 2:37 PM, Dan Williams wrote:
pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid().
Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Cc: Dave Hansen dave@sr71.net Cc: David Airlie airlied@linux.ie Reported-by: Julian Margetson runaway@candw.ms Reported-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Dan Williams dan.j.williams@intel.com
mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 30991f83d0bf..93ce37989471 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
- than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP
- without pte special, it would there be refcounted as a normal page.
*/
- if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) {
- if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) { struct page *page;
- page = pfn_t_to_page(pfn);
- /*
- At this point we are committed to insert_page()
- regardless of whether the caller specified flags that
- result in pfn_t_has_page() == false.
- */
- page = pfn_to_page(pfn_t_to_pfn(pfn)); return insert_page(vma, addr, page, vma->vm_page_prot); } return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
[ 16.503323] systemd[1]: Mounting FUSE Control File System... [ 42.703092] Oops: Machine check, sig: 7 [#1] [ 42.707624] PREEMPT Canyonlands [ 42.710959] Modules linked in: [ 42.714201] CPU: 0 PID: 553 Comm: Xorg Not tainted 4.5.0-rc1-Sam460ex #1 [ 42.721283] task: ee1e45c0 ti: ecd46000 task.ti: ecd46000 [ 42.726983] NIP: 1fed2480 LR: 1fed2404 CTR: 1fed24d0 [ 42.732227] REGS: ecd47f10 TRAP: 0214 Not tainted (4.5.0-rc1-Sam460ex) [ 42.739395] MSR: 0002d000 <CE,EE,PR,ME> CR: 28004262 XER: 00000000 [ 42.746244] GPR00: 1f396134 bfcb0970 b77fc6f0 b6fbeffc b67d5008 00000780 00000004 00000000 GPR08: 00000000 b6fbeffc 00000000 bfcb0920 1fed2404 2076dff4 00000000 00000780 GPR16: 00000000 00000020 00000000 00000000 00001e00 209be650 00000438 b67d5008 GPR24: 00000780 bfcb09c8 209a8728 b6fbf000 b6fbf000 b67d5008 1ffdaff4 00001e00 [ 42.778096] NIP [1fed2480] 0x1fed2480 [ 42.781967] LR [1fed2404] 0x1fed2404 [ 42.785741] Call Trace: [ 42.943688] ---[ end trace 5d20a91d2d30d9d6 ]--- [ 42.948311] [ 46.641774] Machine check in kernel mode. [ 46.645805] Data Write PLB Error [ 46.649031] Machine Check exception is imprecise [ 46.653658] Vector: 214 at [eccfbf10] [ 46.657408] pc: 1ffa9480 [ 46.660325] lr: 1ffa9404 [ 46.663241] sp: bf9252b0 [ 46.666123] msr: 2d000 [ 46.668746] current = 0xee1e73c0 [ 46.672149] pid = 663, comm = Xorg [ 46.676074] Linux version 4.5.0-rc1-Sam460ex (root@julian-VirtualBox)
Ok, I think the patch is still needed for the issue Tomi reported, this appears to be a separate bug.
Can you send me your kernel config?
On 1/26/2016 4:34 PM, Dan Williams wrote:
On Tue, Jan 26, 2016 at 11:46 AM, Julian Margetson runaway@candw.ms wrote:
On 1/26/2016 2:37 PM, Dan Williams wrote:
pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid().
Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t") Cc: Dave Hansen dave@sr71.net Cc: David Airlie airlied@linux.ie Reported-by: Julian Margetson runaway@candw.ms Reported-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Dan Williams dan.j.williams@intel.com
mm/memory.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c index 30991f83d0bf..93ce37989471 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
- than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP
- without pte special, it would there be refcounted as a normal page.
*/
- if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) {
- if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) { struct page *page;
- page = pfn_t_to_page(pfn);
- /*
- At this point we are committed to insert_page()
- regardless of whether the caller specified flags that
- result in pfn_t_has_page() == false.
- */
- page = pfn_to_page(pfn_t_to_pfn(pfn)); return insert_page(vma, addr, page, vma->vm_page_prot); } return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
[ 16.503323] systemd[1]: Mounting FUSE Control File System... [ 42.703092] Oops: Machine check, sig: 7 [#1] [ 42.707624] PREEMPT Canyonlands [ 42.710959] Modules linked in: [ 42.714201] CPU: 0 PID: 553 Comm: Xorg Not tainted 4.5.0-rc1-Sam460ex #1 [ 42.721283] task: ee1e45c0 ti: ecd46000 task.ti: ecd46000 [ 42.726983] NIP: 1fed2480 LR: 1fed2404 CTR: 1fed24d0 [ 42.732227] REGS: ecd47f10 TRAP: 0214 Not tainted (4.5.0-rc1-Sam460ex) [ 42.739395] MSR: 0002d000 <CE,EE,PR,ME> CR: 28004262 XER: 00000000 [ 42.746244] GPR00: 1f396134 bfcb0970 b77fc6f0 b6fbeffc b67d5008 00000780 00000004 00000000 GPR08: 00000000 b6fbeffc 00000000 bfcb0920 1fed2404 2076dff4 00000000 00000780 GPR16: 00000000 00000020 00000000 00000000 00001e00 209be650 00000438 b67d5008 GPR24: 00000780 bfcb09c8 209a8728 b6fbf000 b6fbf000 b67d5008 1ffdaff4 00001e00 [ 42.778096] NIP [1fed2480] 0x1fed2480 [ 42.781967] LR [1fed2404] 0x1fed2404 [ 42.785741] Call Trace: [ 42.943688] ---[ end trace 5d20a91d2d30d9d6 ]--- [ 42.948311] [ 46.641774] Machine check in kernel mode. [ 46.645805] Data Write PLB Error [ 46.649031] Machine Check exception is imprecise [ 46.653658] Vector: 214 at [eccfbf10] [ 46.657408] pc: 1ffa9480 [ 46.660325] lr: 1ffa9404 [ 46.663241] sp: bf9252b0 [ 46.666123] msr: 2d000 [ 46.668746] current = 0xee1e73c0 [ 46.672149] pid = 663, comm = Xorg [ 46.676074] Linux version 4.5.0-rc1-Sam460ex (root@julian-VirtualBox)
Ok, I think the patch is still needed for the issue Tomi reported, this appears to be a separate bug.
Can you send me your kernel config?
On 26/01/16 20:37, Dan Williams wrote:
pfn_t_to_page() honors the flags in the pfn_t value to determine if a pfn is backed by a page. However, vm_insert_mixed() was originally written to use pfn_valid() to make this determination. To restore the old/correct behavior, ignore the pfn_t flags in the !pfn_t_devmap() case and fallback to trusting pfn_valid().
Fixes: 01c8f1c44b83 ("mm, dax, gpu: convert vm_insert_mixed to pfn_t")
Thanks, this fixes the crash with omapdrm.
Tested-by: Tomi Valkeinen tomi.valkeinen@ti.com
Tomi
dri-devel@lists.freedesktop.org
-
Dan Williams -
Julian Margetson -
Tomi Valkeinen