Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
On Tue, Sep 08, 2020 at 07:19:38AM +0200, Christophe Leroy wrote: [...] > >diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > >index 67ebc22cf83d..d9e7d16c2263 100644 > >--- a/include/linux/pgtable.h > >+++ b/include/linux/pgtable.h > >@@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm, > > */ > > #ifndef pgd_addr_end > >-#define pgd_addr_end(pgd, addr, end) > >\ > >-({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ > >-(__boundary - 1 < (end) - 1)? __boundary: (end);\ > >-}) > >+#define pgd_addr_end pgd_addr_end > > I think that #define is pointless, usually there is no such #define > for the default case. Default pgd_addr_end() gets overriden on s390 (arch/s390/include/asm/pgtable.h): #define pgd_addr_end pgd_addr_end static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end) { return rste_addr_end_folded(pgd_val(pgd), addr, end); } > >+static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, > >unsigned long end) > >+{ unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK; > >+return (__boundary - 1 < end - 1) ? __boundary : end; > >+}
Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
Le 08/09/2020 à 17:48, Alexander Gordeev a écrit : On Tue, Sep 08, 2020 at 07:19:38AM +0200, Christophe Leroy wrote: [...] diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 67ebc22cf83d..d9e7d16c2263 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm, */ #ifndef pgd_addr_end -#define pgd_addr_end(pgd, addr, end) \ -({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end); \ -}) +#define pgd_addr_end pgd_addr_end I think that #define is pointless, usually there is no such #define for the default case. Default pgd_addr_end() gets overriden on s390 (arch/s390/include/asm/pgtable.h): #define pgd_addr_end pgd_addr_end static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end) { return rste_addr_end_folded(pgd_val(pgd), addr, end); } Yes, there in s390 the #define is needed to hit the #ifndef pgd_addr_end that's in include/linux/pgtable.h But in include/linux/pgtable.h, there is no need of an #define pgd_addr_end pgd_addr_end I think +static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} Christophe
Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
Le 07/09/2020 à 20:00, Gerald Schaefer a écrit : From: Alexander Gordeev Since pXd_addr_end() macros take pXd page-table entry as a parameter it makes sense to check the entry type on compile. Even though most archs do not make use of page-table entries in pXd_addr_end() calls, checking the type in traversal code paths could help to avoid subtle bugs. Signed-off-by: Alexander Gordeev Signed-off-by: Gerald Schaefer --- include/linux/pgtable.h | 36 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 67ebc22cf83d..d9e7d16c2263 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm, */ #ifndef pgd_addr_end -#define pgd_addr_end(pgd, addr, end) \ -({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end); \ -}) +#define pgd_addr_end pgd_addr_end I think that #define is pointless, usually there is no such #define for the default case. +static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} Please use the standard layout, ie entry { and exit } alone on their line, and space between local vars declaration and the rest. Also remove the leading __ in front of var names as it's not needed once it is not macros anymore. f_name() { some_local_var; do_something(); } #endif #ifndef p4d_addr_end -#define p4d_addr_end(p4d, addr, end) \ -({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end); \ -}) +#define p4d_addr_end p4d_addr_end +static inline unsigned long p4d_addr_end(p4d_t p4d, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + P4D_SIZE) & P4D_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif #ifndef pud_addr_end -#define pud_addr_end(pud, addr, end) \ -({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end); \ -}) +#define pud_addr_end pud_addr_end +static inline unsigned long pud_addr_end(pud_t pud, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PUD_SIZE) & PUD_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif #ifndef pmd_addr_end -#define pmd_addr_end(pmd, addr, end) \ -({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end); \ -}) +#define pmd_addr_end pmd_addr_end +static inline unsigned long pmd_addr_end(pmd_t pmd, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PMD_SIZE) & PMD_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif /*
Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
Hi, Some style comments below. On Mon, Sep 07, 2020 at 08:00:58PM +0200, Gerald Schaefer wrote: > From: Alexander Gordeev > > Since pXd_addr_end() macros take pXd page-table entry as a > parameter it makes sense to check the entry type on compile. > Even though most archs do not make use of page-table entries > in pXd_addr_end() calls, checking the type in traversal code > paths could help to avoid subtle bugs. > > Signed-off-by: Alexander Gordeev > Signed-off-by: Gerald Schaefer > --- > include/linux/pgtable.h | 36 > 1 file changed, 20 insertions(+), 16 deletions(-) > > diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h > index 67ebc22cf83d..d9e7d16c2263 100644 > --- a/include/linux/pgtable.h > +++ b/include/linux/pgtable.h > @@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm, > */ > > #ifndef pgd_addr_end > -#define pgd_addr_end(pgd, addr, end) \ > -({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ > - (__boundary - 1 < (end) - 1)? __boundary: (end);\ > -}) > +#define pgd_addr_end pgd_addr_end > +static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, > unsigned long end) > +{unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK; The code should be on a separate line from the curly brace. Besides, since this is not a macro anymore, I think it would be nicer to use 'boundary' without underscores. This applies to the changes below as well. > + return (__boundary - 1 < end - 1) ? __boundary : end; > +} > #endif > > #ifndef p4d_addr_end > -#define p4d_addr_end(p4d, addr, end) \ > -({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \ > - (__boundary - 1 < (end) - 1)? __boundary: (end);\ > -}) > +#define p4d_addr_end p4d_addr_end > +static inline unsigned long p4d_addr_end(p4d_t p4d, unsigned long addr, > unsigned long end) > +{unsigned long __boundary = (addr + P4D_SIZE) & P4D_MASK; > + return (__boundary - 1 < end - 1) ? __boundary : end; > +} > #endif > > #ifndef pud_addr_end > -#define pud_addr_end(pud, addr, end) \ > -({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \ > - (__boundary - 1 < (end) - 1)? __boundary: (end);\ > -}) > +#define pud_addr_end pud_addr_end > +static inline unsigned long pud_addr_end(pud_t pud, unsigned long addr, > unsigned long end) > +{unsigned long __boundary = (addr + PUD_SIZE) & PUD_MASK; > + return (__boundary - 1 < end - 1) ? __boundary : end; > +} > #endif > > #ifndef pmd_addr_end > -#define pmd_addr_end(pmd, addr, end) \ > -({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \ > - (__boundary - 1 < (end) - 1)? __boundary: (end);\ > -}) > +#define pmd_addr_end pmd_addr_end > +static inline unsigned long pmd_addr_end(pmd_t pmd, unsigned long addr, > unsigned long end) > +{unsigned long __boundary = (addr + PMD_SIZE) & PMD_MASK; > + return (__boundary - 1 < end - 1) ? __boundary : end; > +} > #endif > > /* > -- > 2.17.1 > -- Sincerely yours, Mike.
[RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
From: Alexander Gordeev Since pXd_addr_end() macros take pXd page-table entry as a parameter it makes sense to check the entry type on compile. Even though most archs do not make use of page-table entries in pXd_addr_end() calls, checking the type in traversal code paths could help to avoid subtle bugs. Signed-off-by: Alexander Gordeev Signed-off-by: Gerald Schaefer --- include/linux/pgtable.h | 36 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h index 67ebc22cf83d..d9e7d16c2263 100644 --- a/include/linux/pgtable.h +++ b/include/linux/pgtable.h @@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm, */ #ifndef pgd_addr_end -#define pgd_addr_end(pgd, addr, end) \ -({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end);\ -}) +#define pgd_addr_end pgd_addr_end +static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif #ifndef p4d_addr_end -#define p4d_addr_end(p4d, addr, end) \ -({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end);\ -}) +#define p4d_addr_end p4d_addr_end +static inline unsigned long p4d_addr_end(p4d_t p4d, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + P4D_SIZE) & P4D_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif #ifndef pud_addr_end -#define pud_addr_end(pud, addr, end) \ -({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end);\ -}) +#define pud_addr_end pud_addr_end +static inline unsigned long pud_addr_end(pud_t pud, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PUD_SIZE) & PUD_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif #ifndef pmd_addr_end -#define pmd_addr_end(pmd, addr, end) \ -({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \ - (__boundary - 1 < (end) - 1)? __boundary: (end);\ -}) +#define pmd_addr_end pmd_addr_end +static inline unsigned long pmd_addr_end(pmd_t pmd, unsigned long addr, unsigned long end) +{ unsigned long __boundary = (addr + PMD_SIZE) & PMD_MASK; + return (__boundary - 1 < end - 1) ? __boundary : end; +} #endif /* -- 2.17.1