diff mbox series

mm: Fix pud_alloc_track()

Message ID 20200604074446.23944-1-joro@8bytes.org (mailing list archive)
State New, archived
Headers show
Series mm: Fix pud_alloc_track() | expand

Commit Message

Joerg Roedel June 4, 2020, 7:44 a.m. UTC 
From: Joerg Roedel <jroedel@suse.de>

The pud_alloc_track() needs to do different checks based on whether
__ARCH_HAS_5LEVEL_HACK is defined, like it already does in
pud_alloc(). Otherwise it causes boot failures on PowerPC.

Provide the correct implementations for both possible settings of
__ARCH_HAS_5LEVEL_HACK to fix the boot problems.

Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Fixes: d8626138009b ("mm: add functions to track page directory modifications")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 include/asm-generic/5level-fixup.h |  5 +++++
 include/linux/mm.h                 | 26 +++++++++++++-------------
 2 files changed, 18 insertions(+), 13 deletions(-)

Comments

Mike Rapoport June 4, 2020, 4:48 p.m. UTC | #1 
On Thu, Jun 04, 2020 at 09:44:46AM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
> 
> The pud_alloc_track() needs to do different checks based on whether
> __ARCH_HAS_5LEVEL_HACK is defined, like it already does in
> pud_alloc(). Otherwise it causes boot failures on PowerPC.
> 
> Provide the correct implementations for both possible settings of
> __ARCH_HAS_5LEVEL_HACK to fix the boot problems.

There is a patch in mmotm [1] that completely removes
__ARCH_HAS_5LEVEL_HACK which is a part of the series [2] that updates
p4d folding accross architectures. This should fix boot on PowerPC and
the addition of pXd_alloc_track() for __ARCH_HAS_5LEVEL_HACK wouldn't be
necessary.


[1] https://github.com/hnaz/linux-mm/commit/cfae68792af3731ac902ea6ba5ed8df5a0f6bd2f
[2] https://lore.kernel.org/kvmarm/20200414153455.21744-1-rppt@kernel.org/

> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> Fixes: d8626138009b ("mm: add functions to track page directory modifications")
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
>  include/asm-generic/5level-fixup.h |  5 +++++
>  include/linux/mm.h                 | 26 +++++++++++++-------------
>  2 files changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
> index 58046ddc08d0..afbab31fbd7e 100644
> --- a/include/asm-generic/5level-fixup.h
> +++ b/include/asm-generic/5level-fixup.h
> @@ -17,6 +17,11 @@
>  	((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
>  		NULL : pud_offset(p4d, address))
>  
> +#define pud_alloc_track(mm, p4d, address, mask)					\
> +	((unlikely(pgd_none(*(p4d))) &&						\
> +	  (__pud_alloc(mm, p4d, address) || ({*(mask)|=PGTBL_P4D_MODIFIED;0;})))?	\
> +	  NULL : pud_offset(p4d, address))
> +
>  #define p4d_alloc(mm, pgd, address)		(pgd)
>  #define p4d_alloc_track(mm, pgd, address, mask)	(pgd)
>  #define p4d_offset(pgd, start)			(pgd)
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 66e0977f970a..ad3b31c5bcc3 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2088,35 +2088,35 @@ static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
>  		NULL : pud_offset(p4d, address);
>  }
>  
> -static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
> +static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
>  				     unsigned long address,
>  				     pgtbl_mod_mask *mod_mask)
> -
>  {
> -	if (unlikely(pgd_none(*pgd))) {
> -		if (__p4d_alloc(mm, pgd, address))
> +	if (unlikely(p4d_none(*p4d))) {
> +		if (__pud_alloc(mm, p4d, address))
>  			return NULL;
> -		*mod_mask |= PGTBL_PGD_MODIFIED;
> +		*mod_mask |= PGTBL_P4D_MODIFIED;
>  	}
>  
> -	return p4d_offset(pgd, address);
> +	return pud_offset(p4d, address);
>  }
>  
> -#endif /* !__ARCH_HAS_5LEVEL_HACK */
> -
> -static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
> +static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
>  				     unsigned long address,
>  				     pgtbl_mod_mask *mod_mask)
> +
>  {
> -	if (unlikely(p4d_none(*p4d))) {
> -		if (__pud_alloc(mm, p4d, address))
> +	if (unlikely(pgd_none(*pgd))) {
> +		if (__p4d_alloc(mm, pgd, address))
>  			return NULL;
> -		*mod_mask |= PGTBL_P4D_MODIFIED;
> +		*mod_mask |= PGTBL_PGD_MODIFIED;
>  	}
>  
> -	return pud_offset(p4d, address);
> +	return p4d_offset(pgd, address);
>  }
>  
> +#endif /* !__ARCH_HAS_5LEVEL_HACK */
> +
>  static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
>  {
>  	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
> -- 
> 2.26.2
>
Sedat Dilek June 4, 2020, 4:58 p.m. UTC | #2 
On Thu, Jun 4, 2020 at 6:49 PM Mike Rapoport <rppt@kernel.org> wrote:
>
> On Thu, Jun 04, 2020 at 09:44:46AM +0200, Joerg Roedel wrote:
> > From: Joerg Roedel <jroedel@suse.de>
> >
> > The pud_alloc_track() needs to do different checks based on whether
> > __ARCH_HAS_5LEVEL_HACK is defined, like it already does in
> > pud_alloc(). Otherwise it causes boot failures on PowerPC.
> >
> > Provide the correct implementations for both possible settings of
> > __ARCH_HAS_5LEVEL_HACK to fix the boot problems.
>
> There is a patch in mmotm [1] that completely removes
> __ARCH_HAS_5LEVEL_HACK which is a part of the series [2] that updates
> p4d folding accross architectures. This should fix boot on PowerPC and
> the addition of pXd_alloc_track() for __ARCH_HAS_5LEVEL_HACK wouldn't be
> necessary.
>
>
> [1] https://github.com/hnaz/linux-mm/commit/cfae68792af3731ac902ea6ba5ed8df5a0f6bd2f
> [2] https://lore.kernel.org/kvmarm/20200414153455.21744-1-rppt@kernel.org/
>

That link shows an overview of v4 and is easily downloadable as a
single mbox file.
See " Series = mm: remove __ARCH_HAS_5LEVEL_HACK"

- Sedat -

[1] https://lore.kernel.org/patchwork/project/lkml/list/?series=438627

> > Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> > Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> > Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> > Fixes: d8626138009b ("mm: add functions to track page directory modifications")
> > Signed-off-by: Joerg Roedel <jroedel@suse.de>
> > ---
> >  include/asm-generic/5level-fixup.h |  5 +++++
> >  include/linux/mm.h                 | 26 +++++++++++++-------------
> >  2 files changed, 18 insertions(+), 13 deletions(-)
> >
> > diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
> > index 58046ddc08d0..afbab31fbd7e 100644
> > --- a/include/asm-generic/5level-fixup.h
> > +++ b/include/asm-generic/5level-fixup.h
> > @@ -17,6 +17,11 @@
> >       ((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
> >               NULL : pud_offset(p4d, address))
> >
> > +#define pud_alloc_track(mm, p4d, address, mask)                                      \
> > +     ((unlikely(pgd_none(*(p4d))) &&                                         \
> > +       (__pud_alloc(mm, p4d, address) || ({*(mask)|=PGTBL_P4D_MODIFIED;0;})))?       \
> > +       NULL : pud_offset(p4d, address))
> > +
> >  #define p4d_alloc(mm, pgd, address)          (pgd)
> >  #define p4d_alloc_track(mm, pgd, address, mask)      (pgd)
> >  #define p4d_offset(pgd, start)                       (pgd)
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 66e0977f970a..ad3b31c5bcc3 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2088,35 +2088,35 @@ static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
> >               NULL : pud_offset(p4d, address);
> >  }
> >
> > -static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
> > +static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
> >                                    unsigned long address,
> >                                    pgtbl_mod_mask *mod_mask)
> > -
> >  {
> > -     if (unlikely(pgd_none(*pgd))) {
> > -             if (__p4d_alloc(mm, pgd, address))
> > +     if (unlikely(p4d_none(*p4d))) {
> > +             if (__pud_alloc(mm, p4d, address))
> >                       return NULL;
> > -             *mod_mask |= PGTBL_PGD_MODIFIED;
> > +             *mod_mask |= PGTBL_P4D_MODIFIED;
> >       }
> >
> > -     return p4d_offset(pgd, address);
> > +     return pud_offset(p4d, address);
> >  }
> >
> > -#endif /* !__ARCH_HAS_5LEVEL_HACK */
> > -
> > -static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
> > +static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
> >                                    unsigned long address,
> >                                    pgtbl_mod_mask *mod_mask)
> > +
> >  {
> > -     if (unlikely(p4d_none(*p4d))) {
> > -             if (__pud_alloc(mm, p4d, address))
> > +     if (unlikely(pgd_none(*pgd))) {
> > +             if (__p4d_alloc(mm, pgd, address))
> >                       return NULL;
> > -             *mod_mask |= PGTBL_P4D_MODIFIED;
> > +             *mod_mask |= PGTBL_PGD_MODIFIED;
> >       }
> >
> > -     return pud_offset(p4d, address);
> > +     return p4d_offset(pgd, address);
> >  }
> >
> > +#endif /* !__ARCH_HAS_5LEVEL_HACK */
> > +
> >  static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
> >  {
> >       return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
> > --
> > 2.26.2
> >
>
> --
> Sincerely yours,
> Mike.
Guenter Roeck June 4, 2020, 6:04 p.m. UTC | #3 
On Thu, Jun 04, 2020 at 09:44:46AM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
> 
> The pud_alloc_track() needs to do different checks based on whether
> __ARCH_HAS_5LEVEL_HACK is defined, like it already does in
> pud_alloc(). Otherwise it causes boot failures on PowerPC.
> 
> Provide the correct implementations for both possible settings of
> __ARCH_HAS_5LEVEL_HACK to fix the boot problems.
> 
> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
> Fixes: d8626138009b ("mm: add functions to track page directory modifications")
> Signed-off-by: Joerg Roedel <jroedel@suse.de>

Tested-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  include/asm-generic/5level-fixup.h |  5 +++++
>  include/linux/mm.h                 | 26 +++++++++++++-------------
>  2 files changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
> index 58046ddc08d0..afbab31fbd7e 100644
> --- a/include/asm-generic/5level-fixup.h
> +++ b/include/asm-generic/5level-fixup.h
> @@ -17,6 +17,11 @@
>  	((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
>  		NULL : pud_offset(p4d, address))
>  
> +#define pud_alloc_track(mm, p4d, address, mask)					\
> +	((unlikely(pgd_none(*(p4d))) &&						\
> +	  (__pud_alloc(mm, p4d, address) || ({*(mask)|=PGTBL_P4D_MODIFIED;0;})))?	\
> +	  NULL : pud_offset(p4d, address))
> +
>  #define p4d_alloc(mm, pgd, address)		(pgd)
>  #define p4d_alloc_track(mm, pgd, address, mask)	(pgd)
>  #define p4d_offset(pgd, start)			(pgd)
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 66e0977f970a..ad3b31c5bcc3 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2088,35 +2088,35 @@ static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
>  		NULL : pud_offset(p4d, address);
>  }
>  
> -static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
> +static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
>  				     unsigned long address,
>  				     pgtbl_mod_mask *mod_mask)
> -
>  {
> -	if (unlikely(pgd_none(*pgd))) {
> -		if (__p4d_alloc(mm, pgd, address))
> +	if (unlikely(p4d_none(*p4d))) {
> +		if (__pud_alloc(mm, p4d, address))
>  			return NULL;
> -		*mod_mask |= PGTBL_PGD_MODIFIED;
> +		*mod_mask |= PGTBL_P4D_MODIFIED;
>  	}
>  
> -	return p4d_offset(pgd, address);
> +	return pud_offset(p4d, address);
>  }
>  
> -#endif /* !__ARCH_HAS_5LEVEL_HACK */
> -
> -static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
> +static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
>  				     unsigned long address,
>  				     pgtbl_mod_mask *mod_mask)
> +
>  {
> -	if (unlikely(p4d_none(*p4d))) {
> -		if (__pud_alloc(mm, p4d, address))
> +	if (unlikely(pgd_none(*pgd))) {
> +		if (__p4d_alloc(mm, pgd, address))
>  			return NULL;
> -		*mod_mask |= PGTBL_P4D_MODIFIED;
> +		*mod_mask |= PGTBL_PGD_MODIFIED;
>  	}
>  
> -	return pud_offset(p4d, address);
> +	return p4d_offset(pgd, address);
>  }
>  
> +#endif /* !__ARCH_HAS_5LEVEL_HACK */
> +
>  static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
>  {
>  	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
> -- 
> 2.26.2
>
Andrew Morton June 4, 2020, 8:36 p.m. UTC | #4 
On Thu, 4 Jun 2020 19:48:14 +0300 Mike Rapoport <rppt@kernel.org> wrote:

> On Thu, Jun 04, 2020 at 09:44:46AM +0200, Joerg Roedel wrote:
> > From: Joerg Roedel <jroedel@suse.de>
> > 
> > The pud_alloc_track() needs to do different checks based on whether
> > __ARCH_HAS_5LEVEL_HACK is defined, like it already does in
> > pud_alloc(). Otherwise it causes boot failures on PowerPC.
> > 
> > Provide the correct implementations for both possible settings of
> > __ARCH_HAS_5LEVEL_HACK to fix the boot problems.
> 
> There is a patch in mmotm [1] that completely removes
> __ARCH_HAS_5LEVEL_HACK which is a part of the series [2] that updates
> p4d folding accross architectures. This should fix boot on PowerPC and
> the addition of pXd_alloc_track() for __ARCH_HAS_5LEVEL_HACK wouldn't be
> necessary.
> 
> 
> [1] https://github.com/hnaz/linux-mm/commit/cfae68792af3731ac902ea6ba5ed8df5a0f6bd2f
> [2] https://lore.kernel.org/kvmarm/20200414153455.21744-1-rppt@kernel.org/

That patchset is stacked up behind many other patches, including all
the powerpc stuff in linux-next :(

As it's a big bug fix, I'll pull those patches forward, hopefully send it
all Linuswards later today...
diff mbox series

Patch

diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
index 58046ddc08d0..afbab31fbd7e 100644
--- a/include/asm-generic/5level-fixup.h
+++ b/include/asm-generic/5level-fixup.h
@@ -17,6 +17,11 @@ 
 	((unlikely(pgd_none(*(p4d))) && __pud_alloc(mm, p4d, address)) ? \
 		NULL : pud_offset(p4d, address))
 
+#define pud_alloc_track(mm, p4d, address, mask)					\
+	((unlikely(pgd_none(*(p4d))) &&						\
+	  (__pud_alloc(mm, p4d, address) || ({*(mask)|=PGTBL_P4D_MODIFIED;0;})))?	\
+	  NULL : pud_offset(p4d, address))
+
 #define p4d_alloc(mm, pgd, address)		(pgd)
 #define p4d_alloc_track(mm, pgd, address, mask)	(pgd)
 #define p4d_offset(pgd, start)			(pgd)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 66e0977f970a..ad3b31c5bcc3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2088,35 +2088,35 @@  static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
 		NULL : pud_offset(p4d, address);
 }
 
-static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
+static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
 				     unsigned long address,
 				     pgtbl_mod_mask *mod_mask)
-
 {
-	if (unlikely(pgd_none(*pgd))) {
-		if (__p4d_alloc(mm, pgd, address))
+	if (unlikely(p4d_none(*p4d))) {
+		if (__pud_alloc(mm, p4d, address))
 			return NULL;
-		*mod_mask |= PGTBL_PGD_MODIFIED;
+		*mod_mask |= PGTBL_P4D_MODIFIED;
 	}
 
-	return p4d_offset(pgd, address);
+	return pud_offset(p4d, address);
 }
 
-#endif /* !__ARCH_HAS_5LEVEL_HACK */
-
-static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
+static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
 				     unsigned long address,
 				     pgtbl_mod_mask *mod_mask)
+
 {
-	if (unlikely(p4d_none(*p4d))) {
-		if (__pud_alloc(mm, p4d, address))
+	if (unlikely(pgd_none(*pgd))) {
+		if (__p4d_alloc(mm, pgd, address))
 			return NULL;
-		*mod_mask |= PGTBL_P4D_MODIFIED;
+		*mod_mask |= PGTBL_PGD_MODIFIED;
 	}
 
-	return pud_offset(p4d, address);
+	return p4d_offset(pgd, address);
 }
 
+#endif /* !__ARCH_HAS_5LEVEL_HACK */
+
 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {
 	return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?