* drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458' declared with 'error' attribute: BUILD_BUG failed
@ 2026-07-20 11:36 kernel test robot
2026-07-21 10:40 ` [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION Jan Stancek
0 siblings, 1 reply; 9+ messages in thread
From: kernel test robot @ 2026-07-20 11:36 UTC (permalink / raw)
To: oe-kbuild; +Cc: lkp
::::::
:::::: Manual check reason: "__compiletime_assert_NNN"
::::::
BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
CC: linux-kernel@vger.kernel.org
TO: Matthew Brost <matthew.brost@intel.com>
CC: Francois Dugast <francois.dugast@intel.com>
CC: Balbir Singh <balbirs@nvidia.com>
Hi Matthew,
FYI, the error/warning still remains.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 1590cf0329716306e948a8fc29f1d3ee87d3989f
commit: 139ab31aea8a9436460568d556b432bb7e9311f7 drm/pagemap: Correct cpages calculation for migrate_vma_setup
date: 4 months ago
:::::: branch date: 15 hours ago
:::::: commit date: 4 months ago
config: s390-randconfig-r062-20260720 (https://download.01.org/0day-ci/archive/20260720/202607201914.LpAGsbXs-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260720/202607201914.LpAGsbXs-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
All errors (new ones prefixed by >>):
>> drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458' declared with 'error' attribute: BUILD_BUG failed
480 | order = HPAGE_PMD_ORDER;
| ^
include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
| ^
include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
| ^
include/linux/build_bug.h:59:21: note: expanded from macro 'BUILD_BUG'
59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
| ^
note: (skipping 2 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
include/linux/compiler_types.h:694:2: note: expanded from macro '_compiletime_assert'
694 | __compiletime_assert(condition, msg, prefix, suffix)
| ^
include/linux/compiler_types.h:687:4: note: expanded from macro '__compiletime_assert'
687 | prefix ## suffix(); \
| ^
<scratch space>:91:1: note: expanded from here
91 | __compiletime_assert_458
| ^
1 error generated.
vim +480 drivers/gpu/drm/drm_pagemap.c
ec265e1f1cfcce Thomas Hellström 2025-12-19 454
139ab31aea8a94 Matthew Brost 2026-03-12 455 /**
139ab31aea8a94 Matthew Brost 2026-03-12 456 * drm_pagemap_cpages() - Count collected pages
139ab31aea8a94 Matthew Brost 2026-03-12 457 * @migrate_pfn: Array of migrate_pfn entries to account
139ab31aea8a94 Matthew Brost 2026-03-12 458 * @npages: Number of entries in @migrate_pfn
139ab31aea8a94 Matthew Brost 2026-03-12 459 *
139ab31aea8a94 Matthew Brost 2026-03-12 460 * Compute the total number of minimum-sized pages represented by the
139ab31aea8a94 Matthew Brost 2026-03-12 461 * collected entries in @migrate_pfn. The total is derived from the
139ab31aea8a94 Matthew Brost 2026-03-12 462 * order encoded in each entry.
139ab31aea8a94 Matthew Brost 2026-03-12 463 *
139ab31aea8a94 Matthew Brost 2026-03-12 464 * Return: Total number of minimum-sized pages.
139ab31aea8a94 Matthew Brost 2026-03-12 465 */
139ab31aea8a94 Matthew Brost 2026-03-12 466 static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
139ab31aea8a94 Matthew Brost 2026-03-12 467 {
139ab31aea8a94 Matthew Brost 2026-03-12 468 unsigned long i, cpages = 0;
139ab31aea8a94 Matthew Brost 2026-03-12 469
139ab31aea8a94 Matthew Brost 2026-03-12 470 for (i = 0; i < npages;) {
139ab31aea8a94 Matthew Brost 2026-03-12 471 struct page *page = migrate_pfn_to_page(migrate_pfn[i]);
139ab31aea8a94 Matthew Brost 2026-03-12 472 struct folio *folio;
139ab31aea8a94 Matthew Brost 2026-03-12 473 unsigned int order = 0;
139ab31aea8a94 Matthew Brost 2026-03-12 474
139ab31aea8a94 Matthew Brost 2026-03-12 475 if (page) {
139ab31aea8a94 Matthew Brost 2026-03-12 476 folio = page_folio(page);
139ab31aea8a94 Matthew Brost 2026-03-12 477 order = folio_order(folio);
139ab31aea8a94 Matthew Brost 2026-03-12 478 cpages += NR_PAGES(order);
139ab31aea8a94 Matthew Brost 2026-03-12 479 } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
139ab31aea8a94 Matthew Brost 2026-03-12 @480 order = HPAGE_PMD_ORDER;
139ab31aea8a94 Matthew Brost 2026-03-12 481 cpages += NR_PAGES(order);
139ab31aea8a94 Matthew Brost 2026-03-12 482 }
139ab31aea8a94 Matthew Brost 2026-03-12 483
139ab31aea8a94 Matthew Brost 2026-03-12 484 i += NR_PAGES(order);
139ab31aea8a94 Matthew Brost 2026-03-12 485 }
139ab31aea8a94 Matthew Brost 2026-03-12 486
139ab31aea8a94 Matthew Brost 2026-03-12 487 return cpages;
139ab31aea8a94 Matthew Brost 2026-03-12 488 }
139ab31aea8a94 Matthew Brost 2026-03-12 489
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 9+ messages in thread* [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-20 11:36 drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458' declared with 'error' attribute: BUILD_BUG failed kernel test robot
@ 2026-07-21 10:40 ` Jan Stancek
2026-07-21 10:56 ` sashiko-bot
2026-07-21 19:12 ` Matthew Brost
0 siblings, 2 replies; 9+ messages in thread
From: Jan Stancek @ 2026-07-21 10:40 UTC (permalink / raw)
To: dri-devel
Cc: linux-kernel, maarten.lankhorst, mripard, tzimmermann, airlied,
simona, matthew.brost, jstancek
HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
and CONFIG_HUGETLB_PAGE are disabled:
drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
declared with 'error' attribute: BUILD_BUG failed
480 | order = HPAGE_PMD_ORDER;
| ^
include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
| ^
include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
Guard the two HPAGE_PMD_ORDER uses with CONFIG_ARCH_ENABLE_THP_MIGRATION,
matching the pattern used in migrate_device.c.
Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
Signed-off-by: Jan Stancek <jstancek@redhat.com>
---
drivers/gpu/drm/drm_pagemap.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index 15c78eca180b..53a78752c8be 100644
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -578,10 +578,13 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
folio = page_folio(page);
order = folio_order(folio);
cpages += NR_PAGES(order);
- } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
+ }
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+ else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
order = HPAGE_PMD_ORDER;
cpages += NR_PAGES(order);
}
+#endif
i += NR_PAGES(order);
}
@@ -733,7 +736,6 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
own_pages = 0;
for (i = 0; i < npages;) {
- unsigned long j;
struct page *page = pfn_to_page(migrate.dst[i]);
struct page *src_page = migrate_pfn_to_page(migrate.src[i]);
unsigned int order = 0;
@@ -763,7 +765,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
}
migrate.dst[i] = migrate_pfn(migrate.dst[i]);
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
+ unsigned long j;
+
drm_WARN_ONCE(dpagemap->drm, src_page &&
folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
"Unexpected folio order\n");
@@ -774,6 +779,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
migrate.dst[i + j] = 0;
}
+#endif
drm_pagemap_get_devmem_page(page, order, zdd);
--
2.52.0
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 10:40 ` [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION Jan Stancek
@ 2026-07-21 10:56 ` sashiko-bot
2026-07-21 19:12 ` Matthew Brost
1 sibling, 0 replies; 9+ messages in thread
From: sashiko-bot @ 2026-07-21 10:56 UTC (permalink / raw)
To: Jan Stancek; +Cc: dri-devel
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [Critical] Aborting a migration mid-loop leaves raw device PFNs in the migration array, causing a bogus pointer dereference and kernel panic in migrate_vma_pages().
--
--- Patch [1]: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION ---
commit 66a306e51148532e3b7d883d3232632355c05797
Author: Jan Stancek <jstancek@redhat.com>
drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
This commit fixes a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
and CONFIG_HUGETLB_PAGE are disabled. It guards HPAGE_PMD_ORDER uses with
CONFIG_ARCH_ENABLE_THP_MIGRATION.
Link: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> index 15c78eca180b7..53a78752c8be3 100644
> --- a/drivers/gpu/drm/drm_pagemap.c
> +++ b/drivers/gpu/drm/drm_pagemap.c
[ ... ]
> @@ -763,7 +765,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> }
> migrate.dst[i] = migrate_pfn(migrate.dst[i]);
>
> +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
> + unsigned long j;
> +
> drm_WARN_ONCE(dpagemap->drm, src_page &&
> folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
> "Unexpected folio order\n");
> @@ -774,6 +779,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
> migrate.dst[i + j] = 0;
> }
> +#endif
>
> drm_pagemap_get_devmem_page(page, order, zdd);
[Severity: Critical]
This is a pre-existing issue, but can the error path here leave raw device
PFNs in the migration array, causing a bogus pointer dereference in
migrate_vma_pages()?
In drm_pagemap_migrate_to_devmem(), ops->populate_devmem_pfn() populates
migrate.dst with sequential raw device PFNs. The loop processes these and
converts them into the migrate_pfn() format. If a migration batch fails
mid-loop:
err = drm_pagemap_migrate_range(...);
if (err) {
npages = i + 1;
goto err_finalize;
}
The error path zeros out migrate.dst entries up to index i, and then
falls through to err_aborted_migration:
err_finalize:
if (err)
drm_pagemap_migration_unlock_put_pages(npages, migrate.dst);
err_aborted_migration:
migrate_vma_pages(&migrate);
Because migrate_vma_pages() iterates up to the original migrate.npages,
unprocessed entries (where index > i) still contain unformatted raw PFNs.
Since PFNs are sequential, half of them are odd numbers, meaning bit 0
(MIGRATE_PFN_VALID) is set.
Will __migrate_device_pages() misinterpret these odd raw PFNs as valid
migration entries, leading to a dereference of a completely bogus
struct page pointer when it calls pfn_to_page()?
--
Sashiko AI review · https://sashiko.dev/#/patchset/84a35e16f72330d6e7b2d6e969040f36959e2dad.1784630290.git.jstancek@redhat.com?part=1
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 10:40 ` [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION Jan Stancek
2026-07-21 10:56 ` sashiko-bot
@ 2026-07-21 19:12 ` Matthew Brost
2026-07-21 19:15 ` Matthew Brost
1 sibling, 1 reply; 9+ messages in thread
From: Matthew Brost @ 2026-07-21 19:12 UTC (permalink / raw)
To: Jan Stancek
Cc: dri-devel, linux-kernel, maarten.lankhorst, mripard, tzimmermann,
airlied, simona
On Tue, Jul 21, 2026 at 12:40:38PM +0200, Jan Stancek wrote:
> HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
> is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
> and CONFIG_HUGETLB_PAGE are disabled:
>
> drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
> declared with 'error' attribute: BUILD_BUG failed
> 480 | order = HPAGE_PMD_ORDER;
> | ^
> include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
> 117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
> | ^
> include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
> 113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
>
> Guard the two HPAGE_PMD_ORDER uses with CONFIG_ARCH_ENABLE_THP_MIGRATION,
> matching the pattern used in migrate_device.c.
>
> Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> Signed-off-by: Jan Stancek <jstancek@redhat.com>
> ---
> drivers/gpu/drm/drm_pagemap.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> index 15c78eca180b..53a78752c8be 100644
> --- a/drivers/gpu/drm/drm_pagemap.c
> +++ b/drivers/gpu/drm/drm_pagemap.c
> @@ -578,10 +578,13 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
> folio = page_folio(page);
> order = folio_order(folio);
> cpages += NR_PAGES(order);
> - } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> + }
> +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> + else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> order = HPAGE_PMD_ORDER;
Would it be do something like this at the top of the file...
#ifdef HPAGE_PMD_ORDER
#define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
#else
#define DRM_PAGEMAP_PMD_ORDER (-1)
#endif
Then in common code s/HPAGE_PMD_ORDER/DRM_PAGEMAP_PMD_ORDER/
I think this works as we can never get to the MIGRATE_PFN_COMPOUND code
paths without CONFIG_ARCH_ENABLE_THP_MIGRATION enabled (see
mm/migrate_device.c).
Also btw fixing the unrelated bug Sashiko flagged in this patch.
Matt
> cpages += NR_PAGES(order);
> }
> +#endif
>
> i += NR_PAGES(order);
> }
> @@ -733,7 +736,6 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> own_pages = 0;
>
> for (i = 0; i < npages;) {
> - unsigned long j;
> struct page *page = pfn_to_page(migrate.dst[i]);
> struct page *src_page = migrate_pfn_to_page(migrate.src[i]);
> unsigned int order = 0;
> @@ -763,7 +765,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> }
> migrate.dst[i] = migrate_pfn(migrate.dst[i]);
>
> +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
> + unsigned long j;
> +
> drm_WARN_ONCE(dpagemap->drm, src_page &&
> folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
> "Unexpected folio order\n");
> @@ -774,6 +779,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
> migrate.dst[i + j] = 0;
> }
> +#endif
>
> drm_pagemap_get_devmem_page(page, order, zdd);
>
> --
> 2.52.0
>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 19:12 ` Matthew Brost
@ 2026-07-21 19:15 ` Matthew Brost
2026-07-21 19:35 ` Jan Stancek
0 siblings, 1 reply; 9+ messages in thread
From: Matthew Brost @ 2026-07-21 19:15 UTC (permalink / raw)
To: Jan Stancek
Cc: dri-devel, linux-kernel, maarten.lankhorst, mripard, tzimmermann,
airlied, simona
On Tue, Jul 21, 2026 at 12:12:01PM -0700, Matthew Brost wrote:
> On Tue, Jul 21, 2026 at 12:40:38PM +0200, Jan Stancek wrote:
> > HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
> > is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
> > and CONFIG_HUGETLB_PAGE are disabled:
> >
> > drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
> > declared with 'error' attribute: BUILD_BUG failed
> > 480 | order = HPAGE_PMD_ORDER;
> > | ^
> > include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
> > 117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
> > | ^
> > include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
> > 113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
> >
> > Guard the two HPAGE_PMD_ORDER uses with CONFIG_ARCH_ENABLE_THP_MIGRATION,
> > matching the pattern used in migrate_device.c.
> >
> > Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> > Signed-off-by: Jan Stancek <jstancek@redhat.com>
> > ---
> > drivers/gpu/drm/drm_pagemap.c | 10 ++++++++--
> > 1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> > index 15c78eca180b..53a78752c8be 100644
> > --- a/drivers/gpu/drm/drm_pagemap.c
> > +++ b/drivers/gpu/drm/drm_pagemap.c
> > @@ -578,10 +578,13 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
> > folio = page_folio(page);
> > order = folio_order(folio);
> > cpages += NR_PAGES(order);
> > - } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> > + }
> > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> > + else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> > order = HPAGE_PMD_ORDER;
>
> Would it be do something like this at the top of the file...
>
> #ifdef HPAGE_PMD_ORDER
> #define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
> #else
> #define DRM_PAGEMAP_PMD_ORDER (-1)
> #endif
>
Opps screwed my snippet up - HPAGE_PMD_ORDER seems to be always defined...
So actually...
#if IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)
#define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
#else
define DRM_PAGEMAP_PMD_ORDER (-1)
#endif
Matt
> Then in common code s/HPAGE_PMD_ORDER/DRM_PAGEMAP_PMD_ORDER/
>
> I think this works as we can never get to the MIGRATE_PFN_COMPOUND code
> paths without CONFIG_ARCH_ENABLE_THP_MIGRATION enabled (see
> mm/migrate_device.c).
>
> Also btw fixing the unrelated bug Sashiko flagged in this patch.
>
> Matt
>
> > cpages += NR_PAGES(order);
> > }
> > +#endif
> >
> > i += NR_PAGES(order);
> > }
> > @@ -733,7 +736,6 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > own_pages = 0;
> >
> > for (i = 0; i < npages;) {
> > - unsigned long j;
> > struct page *page = pfn_to_page(migrate.dst[i]);
> > struct page *src_page = migrate_pfn_to_page(migrate.src[i]);
> > unsigned int order = 0;
> > @@ -763,7 +765,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > }
> > migrate.dst[i] = migrate_pfn(migrate.dst[i]);
> >
> > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> > if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
> > + unsigned long j;
> > +
> > drm_WARN_ONCE(dpagemap->drm, src_page &&
> > folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
> > "Unexpected folio order\n");
> > @@ -774,6 +779,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
> > migrate.dst[i + j] = 0;
> > }
> > +#endif
> >
> > drm_pagemap_get_devmem_page(page, order, zdd);
> >
> > --
> > 2.52.0
> >
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 19:15 ` Matthew Brost
@ 2026-07-21 19:35 ` Jan Stancek
0 siblings, 0 replies; 9+ messages in thread
From: Jan Stancek @ 2026-07-21 19:35 UTC (permalink / raw)
To: Matthew Brost
Cc: dri-devel, linux-kernel, maarten.lankhorst, mripard, tzimmermann,
airlied, simona
On Tue, Jul 21, 2026 at 9:15 PM Matthew Brost <matthew.brost@intel.com> wrote:
>
> On Tue, Jul 21, 2026 at 12:12:01PM -0700, Matthew Brost wrote:
> > On Tue, Jul 21, 2026 at 12:40:38PM +0200, Jan Stancek wrote:
> > > HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
> > > is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
> > > and CONFIG_HUGETLB_PAGE are disabled:
> > >
> > > drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
> > > declared with 'error' attribute: BUILD_BUG failed
> > > 480 | order = HPAGE_PMD_ORDER;
> > > | ^
> > > include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
> > > 117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
> > > | ^
> > > include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
> > > 113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
> > >
> > > Guard the two HPAGE_PMD_ORDER uses with CONFIG_ARCH_ENABLE_THP_MIGRATION,
> > > matching the pattern used in migrate_device.c.
> > >
> > > Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
> > > Reported-by: kernel test robot <lkp@intel.com>
> > > Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> > > Signed-off-by: Jan Stancek <jstancek@redhat.com>
> > > ---
> > > drivers/gpu/drm/drm_pagemap.c | 10 ++++++++--
> > > 1 file changed, 8 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> > > index 15c78eca180b..53a78752c8be 100644
> > > --- a/drivers/gpu/drm/drm_pagemap.c
> > > +++ b/drivers/gpu/drm/drm_pagemap.c
> > > @@ -578,10 +578,13 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
> > > folio = page_folio(page);
> > > order = folio_order(folio);
> > > cpages += NR_PAGES(order);
> > > - } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> > > + }
> > > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> > > + else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> > > order = HPAGE_PMD_ORDER;
> >
> > Would it be do something like this at the top of the file...
> >
> > #ifdef HPAGE_PMD_ORDER
> > #define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
> > #else
> > #define DRM_PAGEMAP_PMD_ORDER (-1)
> > #endif
> >
>
> Opps screwed my snippet up - HPAGE_PMD_ORDER seems to be always defined...
>
> So actually...
>
> #if IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)
> #define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
> #else
> define DRM_PAGEMAP_PMD_ORDER (-1)
> #endif
Works for me.
Feel free to add:
Tested-by: Jan Stancek <jstancek@redhat.com>
if you'll be posting your version.
Thanks,
Jan
>
> Matt
>
> > Then in common code s/HPAGE_PMD_ORDER/DRM_PAGEMAP_PMD_ORDER/
> >
> > I think this works as we can never get to the MIGRATE_PFN_COMPOUND code
> > paths without CONFIG_ARCH_ENABLE_THP_MIGRATION enabled (see
> > mm/migrate_device.c).
> >
> > Also btw fixing the unrelated bug Sashiko flagged in this patch.
> >
> > Matt
> >
> > > cpages += NR_PAGES(order);
> > > }
> > > +#endif
> > >
> > > i += NR_PAGES(order);
> > > }
> > > @@ -733,7 +736,6 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > > own_pages = 0;
> > >
> > > for (i = 0; i < npages;) {
> > > - unsigned long j;
> > > struct page *page = pfn_to_page(migrate.dst[i]);
> > > struct page *src_page = migrate_pfn_to_page(migrate.src[i]);
> > > unsigned int order = 0;
> > > @@ -763,7 +765,10 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > > }
> > > migrate.dst[i] = migrate_pfn(migrate.dst[i]);
> > >
> > > +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
> > > if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
> > > + unsigned long j;
> > > +
> > > drm_WARN_ONCE(dpagemap->drm, src_page &&
> > > folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
> > > "Unexpected folio order\n");
> > > @@ -774,6 +779,7 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
> > > for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
> > > migrate.dst[i + j] = 0;
> > > }
> > > +#endif
> > >
> > > drm_pagemap_get_devmem_page(page, order, zdd);
> > >
> > > --
> > > 2.52.0
> > >
>
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
@ 2026-07-21 22:32 Matthew Brost
2026-07-22 5:21 ` Jan Stancek
2026-07-22 5:32 ` Ghimiray, Himal Prasad
0 siblings, 2 replies; 9+ messages in thread
From: Matthew Brost @ 2026-07-21 22:32 UTC (permalink / raw)
To: intel-xe, dri-devel; +Cc: kernel test robot, Jan Stancek
HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
and CONFIG_HUGETLB_PAGE are disabled:
drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
declared with 'error' attribute: BUILD_BUG failed
480 | order = HPAGE_PMD_ORDER;
| ^
include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
| ^
include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
Define DRM_PAGEMAP_PMD_ORDER, which maps to HPAGE_PMD_ORDER when
CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled and to -1 otherwise.
This is safe because all code paths that use DRM_PAGEMAP_PMD_ORDER are
reachable only when CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled.
Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
Cc: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
drivers/gpu/drm/drm_pagemap.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
index 15c78eca180b..951cd92c930c 100644
--- a/drivers/gpu/drm/drm_pagemap.c
+++ b/drivers/gpu/drm/drm_pagemap.c
@@ -12,6 +12,12 @@
#include <drm/drm_pagemap_util.h>
#include <drm/drm_print.h>
+#if IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)
+#define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
+#else
+#define DRM_PAGEMAP_PMD_ORDER (-1)
+#endif
+
/**
* DOC: Overview
*
@@ -579,7 +585,7 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
order = folio_order(folio);
cpages += NR_PAGES(order);
} else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
- order = HPAGE_PMD_ORDER;
+ order = DRM_PAGEMAP_PMD_ORDER;
cpages += NR_PAGES(order);
}
@@ -765,10 +771,11 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
drm_WARN_ONCE(dpagemap->drm, src_page &&
- folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
+ folio_order(page_folio(src_page)) !=
+ DRM_PAGEMAP_PMD_ORDER,
"Unexpected folio order\n");
- order = HPAGE_PMD_ORDER;
+ order = DRM_PAGEMAP_PMD_ORDER;
migrate.dst[i] |= MIGRATE_PFN_COMPOUND;
for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
--
2.34.1
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 22:32 Matthew Brost
@ 2026-07-22 5:21 ` Jan Stancek
2026-07-22 5:32 ` Ghimiray, Himal Prasad
1 sibling, 0 replies; 9+ messages in thread
From: Jan Stancek @ 2026-07-22 5:21 UTC (permalink / raw)
To: Matthew Brost; +Cc: intel-xe, dri-devel, kernel test robot
On Wed, Jul 22, 2026 at 12:32 AM Matthew Brost <matthew.brost@intel.com> wrote:
>
> HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
> is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
> and CONFIG_HUGETLB_PAGE are disabled:
>
> drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
> declared with 'error' attribute: BUILD_BUG failed
> 480 | order = HPAGE_PMD_ORDER;
> | ^
> include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
> 117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
> | ^
> include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
> 113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
>
> Define DRM_PAGEMAP_PMD_ORDER, which maps to HPAGE_PMD_ORDER when
> CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled and to -1 otherwise.
>
> This is safe because all code paths that use DRM_PAGEMAP_PMD_ORDER are
> reachable only when CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled.
>
> Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> Cc: Jan Stancek <jstancek@redhat.com>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Thanks for fix, this resolves (same) build failure I was seeing as well.
Tested-by: Jan Stancek <jstancek@redhat.com>
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION
2026-07-21 22:32 Matthew Brost
2026-07-22 5:21 ` Jan Stancek
@ 2026-07-22 5:32 ` Ghimiray, Himal Prasad
1 sibling, 0 replies; 9+ messages in thread
From: Ghimiray, Himal Prasad @ 2026-07-22 5:32 UTC (permalink / raw)
To: Matthew Brost, intel-xe, dri-devel; +Cc: kernel test robot, Jan Stancek
On 22-07-2026 04:02, Matthew Brost wrote:
> HPAGE_PMD_SHIFT expands to BUILD_BUG() when CONFIG_PGTABLE_HAS_HUGE_LEAVES
> is not set, causing a compile error when both CONFIG_TRANSPARENT_HUGEPAGE
> and CONFIG_HUGETLB_PAGE are disabled:
>
> drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458'
> declared with 'error' attribute: BUILD_BUG failed
> 480 | order = HPAGE_PMD_ORDER;
> | ^
> include/linux/huge_mm.h:117:26: note: expanded from macro 'HPAGE_PMD_ORDER'
> 117 | #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
> | ^
> include/linux/huge_mm.h:113:28: note: expanded from macro 'HPAGE_PMD_SHIFT'
> 113 | #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
>
> Define DRM_PAGEMAP_PMD_ORDER, which maps to HPAGE_PMD_ORDER when
> CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled and to -1 otherwise.
>
> This is safe because all code paths that use DRM_PAGEMAP_PMD_ORDER are
> reachable only when CONFIG_ARCH_ENABLE_THP_MIGRATION is enabled.
>
> Fixes: 139ab31aea8a ("drm/pagemap: Correct cpages calculation for migrate_vma_setup")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/r/202607201914.LpAGsbXs-lkp@intel.com/
> Cc: Jan Stancek <jstancek@redhat.com>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> ---
> drivers/gpu/drm/drm_pagemap.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_pagemap.c b/drivers/gpu/drm/drm_pagemap.c
> index 15c78eca180b..951cd92c930c 100644
> --- a/drivers/gpu/drm/drm_pagemap.c
> +++ b/drivers/gpu/drm/drm_pagemap.c
> @@ -12,6 +12,12 @@
> #include <drm/drm_pagemap_util.h>
> #include <drm/drm_print.h>
>
> +#if IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)
> +#define DRM_PAGEMAP_PMD_ORDER HPAGE_PMD_ORDER
> +#else
> +#define DRM_PAGEMAP_PMD_ORDER (-1)
> +#endif
> +
> /**
> * DOC: Overview
> *
> @@ -579,7 +585,7 @@ static int drm_pagemap_cpages(unsigned long *migrate_pfn, unsigned long npages)
> order = folio_order(folio);
> cpages += NR_PAGES(order);
> } else if (migrate_pfn[i] & MIGRATE_PFN_COMPOUND) {
> - order = HPAGE_PMD_ORDER;
> + order = DRM_PAGEMAP_PMD_ORDER;
> cpages += NR_PAGES(order);
> }
>
> @@ -765,10 +771,11 @@ int drm_pagemap_migrate_to_devmem(struct drm_pagemap_devmem *devmem_allocation,
>
> if (migrate.src[i] & MIGRATE_PFN_COMPOUND) {
> drm_WARN_ONCE(dpagemap->drm, src_page &&
> - folio_order(page_folio(src_page)) != HPAGE_PMD_ORDER,
> + folio_order(page_folio(src_page)) !=
> + DRM_PAGEMAP_PMD_ORDER,
> "Unexpected folio order\n");
>
> - order = HPAGE_PMD_ORDER;
> + order = DRM_PAGEMAP_PMD_ORDER;
> migrate.dst[i] |= MIGRATE_PFN_COMPOUND;
>
> for (j = 1; j < NR_PAGES(order) && i + j < npages; j++)
^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2026-07-22 5:32 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-20 11:36 drivers/gpu/drm/drm_pagemap.c:480:12: error: call to '__compiletime_assert_458' declared with 'error' attribute: BUILD_BUG failed kernel test robot
2026-07-21 10:40 ` [PATCH] drm/pagemap: Guard HPAGE_PMD_ORDER use with CONFIG_ARCH_ENABLE_THP_MIGRATION Jan Stancek
2026-07-21 10:56 ` sashiko-bot
2026-07-21 19:12 ` Matthew Brost
2026-07-21 19:15 ` Matthew Brost
2026-07-21 19:35 ` Jan Stancek
-- strict thread matches above, loose matches on Subject: below --
2026-07-21 22:32 Matthew Brost
2026-07-22 5:21 ` Jan Stancek
2026-07-22 5:32 ` Ghimiray, Himal Prasad
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