* [bug report] mm-add-apply_to_existing_pages-helper-fix
@ 2019-12-12 9:29 Dan Carpenter
2019-12-13 1:03 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Dan Carpenter @ 2019-12-12 9:29 UTC (permalink / raw)
To: akpm; +Cc: linux-mm
Hello Andrew Morton,
The patch 3264ba9274f5: "mm-add-apply_to_existing_pages-helper-fix"
from Dec 11, 2019, leads to the following static checker warning:
mm/memory.c:2166 __apply_to_page_range()
error: uninitialized symbol 'err'.
mm/memory.c
2144 static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
2145 unsigned long size, pte_fn_t fn,
2146 void *data, bool create)
2147 {
2148 pgd_t *pgd;
2149 unsigned long next;
2150 unsigned long end = addr + size;
2151 int err;
2152
2153 if (WARN_ON(addr >= end))
2154 return -EINVAL;
2155
2156 pgd = pgd_offset(mm, addr);
2157 do {
2158 next = pgd_addr_end(addr, end);
2159 if (!create && pgd_none_or_clear_bad(pgd))
2160 continue;
^^^^^^^^^
It feels unlikely that we would always hit this continue but Smatch
complains.
2161 err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create);
2162 if (err)
2163 break;
2164 } while (pgd++, addr = next, addr != end);
2165
2166 return err;
2167 }
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [bug report] mm-add-apply_to_existing_pages-helper-fix 2019-12-12 9:29 [bug report] mm-add-apply_to_existing_pages-helper-fix Dan Carpenter @ 2019-12-13 1:03 ` Andrew Morton 2019-12-13 2:04 ` Daniel Axtens 0 siblings, 1 reply; 3+ messages in thread From: Andrew Morton @ 2019-12-13 1:03 UTC (permalink / raw) To: Dan Carpenter; +Cc: linux-mm, Daniel Axtens On Thu, 12 Dec 2019 12:29:49 +0300 Dan Carpenter <dan.carpenter@oracle.com> wrote: > Hello Andrew Morton, > > The patch 3264ba9274f5: "mm-add-apply_to_existing_pages-helper-fix" > from Dec 11, 2019, leads to the following static checker warning: > > mm/memory.c:2166 __apply_to_page_range() > error: uninitialized symbol 'err'. > > mm/memory.c > 2144 static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, > 2145 unsigned long size, pte_fn_t fn, > 2146 void *data, bool create) > 2147 { > 2148 pgd_t *pgd; > 2149 unsigned long next; > 2150 unsigned long end = addr + size; > 2151 int err; > 2152 > 2153 if (WARN_ON(addr >= end)) > 2154 return -EINVAL; > 2155 > 2156 pgd = pgd_offset(mm, addr); > 2157 do { > 2158 next = pgd_addr_end(addr, end); > 2159 if (!create && pgd_none_or_clear_bad(pgd)) > 2160 continue; > ^^^^^^^^^ > It feels unlikely that we would always hit this continue but Smatch > complains. > Thanks. --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix-fix-fix +++ a/mm/memory.c @@ -2148,7 +2148,7 @@ static int __apply_to_page_range(struct pgd_t *pgd; unsigned long next; unsigned long end = addr + size; - int err; + int err = 0; if (WARN_ON(addr >= end)) return -EINVAL; Daniel, have you had a chance to runtime test these various fiddles? From: Andrew Morton <akpm@linux-foundation.org> Subject: mm-add-apply_to_existing_pages-helper-fix reduce code duplication Cc: Daniel Axtens <dja@axtens.net> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/memory.c | 43 +++++++++++++++++-------------------------- 1 file changed, 17 insertions(+), 26 deletions(-) --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix +++ a/mm/memory.c @@ -2141,12 +2141,9 @@ static int apply_to_p4d_range(struct mm_ return err; } -/* - * Scan a region of virtual memory, filling in page tables as necessary - * and calling a provided function on each leaf page table. - */ -int apply_to_page_range(struct mm_struct *mm, unsigned long addr, - unsigned long size, pte_fn_t fn, void *data) +static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, + unsigned long size, pte_fn_t fn, + void *data, bool create) { pgd_t *pgd; unsigned long next; @@ -2159,13 +2156,25 @@ int apply_to_page_range(struct mm_struct pgd = pgd_offset(mm, addr); do { next = pgd_addr_end(addr, end); - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, true); + if (!create && pgd_none_or_clear_bad(pgd)) + continue; + err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create); if (err) break; } while (pgd++, addr = next, addr != end); return err; } + +/* + * Scan a region of virtual memory, filling in page tables as necessary + * and calling a provided function on each leaf page table. + */ +int apply_to_page_range(struct mm_struct *mm, unsigned long addr, + unsigned long size, pte_fn_t fn, void *data) +{ + return __apply_to_page_range(mm, addr, size, fn, data, true); +} EXPORT_SYMBOL_GPL(apply_to_page_range); /* @@ -2178,25 +2187,7 @@ EXPORT_SYMBOL_GPL(apply_to_page_range); int apply_to_existing_pages(struct mm_struct *mm, unsigned long addr, unsigned long size, pte_fn_t fn, void *data) { - pgd_t *pgd; - unsigned long next; - unsigned long end = addr + size; - int err = 0; - - if (WARN_ON(addr >= end)) - return -EINVAL; - - pgd = pgd_offset(mm, addr); - do { - next = pgd_addr_end(addr, end); - if (pgd_none_or_clear_bad(pgd)) - continue; - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, false); - if (err) - break; - } while (pgd++, addr = next, addr != end); - - return err; + return __apply_to_page_range(mm, addr, size, fn, data, false); } EXPORT_SYMBOL_GPL(apply_to_existing_pages); _ From: Andrew Morton <akpm@linux-foundation.org> Subject: mm-add-apply_to_existing_pages-helper-fix-fix s/apply_to_existing_pages/apply_to_existing_page_range/ Cc: Daniel Axtens <dja@axtens.net> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- include/linux/mm.h | 6 +++--- mm/memory.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) --- a/include/linux/mm.h~mm-add-apply_to_existing_pages-helper-fix-fix +++ a/include/linux/mm.h @@ -2621,9 +2621,9 @@ static inline int vm_fault_to_errno(vm_f typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, unsigned long size, pte_fn_t fn, void *data); -extern int apply_to_existing_pages(struct mm_struct *mm, unsigned long address, - unsigned long size, pte_fn_t fn, - void *data); +extern int apply_to_existing_page_range(struct mm_struct *mm, + unsigned long address, unsigned long size, + pte_fn_t fn, void *data); #ifdef CONFIG_PAGE_POISONING extern bool page_poisoning_enabled(void); --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix-fix +++ a/mm/memory.c @@ -2184,12 +2184,12 @@ EXPORT_SYMBOL_GPL(apply_to_page_range); * Unlike apply_to_page_range, this does _not_ fill in page tables * where they are absent. */ -int apply_to_existing_pages(struct mm_struct *mm, unsigned long addr, - unsigned long size, pte_fn_t fn, void *data) +int apply_to_existing_page_range(struct mm_struct *mm, unsigned long addr, + unsigned long size, pte_fn_t fn, void *data) { return __apply_to_page_range(mm, addr, size, fn, data, false); } -EXPORT_SYMBOL_GPL(apply_to_existing_pages); +EXPORT_SYMBOL_GPL(apply_to_existing_page_range); /* * handle_pte_fault chooses page fault handler according to an entry which was _ From: Andrew Morton <akpm@linux-foundation.org> Subject: mm-add-apply_to_existing_pages-helper-fix-fix-fix initialize __apply_to_page_range::err Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Qian Cai <cai@lca.pw> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix-fix-fix +++ a/mm/memory.c @@ -2148,7 +2148,7 @@ static int __apply_to_page_range(struct pgd_t *pgd; unsigned long next; unsigned long end = addr + size; - int err; + int err = 0; if (WARN_ON(addr >= end)) return -EINVAL; _ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [bug report] mm-add-apply_to_existing_pages-helper-fix 2019-12-13 1:03 ` Andrew Morton @ 2019-12-13 2:04 ` Daniel Axtens 0 siblings, 0 replies; 3+ messages in thread From: Daniel Axtens @ 2019-12-13 2:04 UTC (permalink / raw) To: Andrew Morton, Dan Carpenter; +Cc: linux-mm Hi Andrew, > Daniel, have you had a chance to runtime test these various fiddles? Yes, I've been testing with -fix and -fix-fix since they hit next. They work fine for me on x86 and powerpc. Regards, Daniel > > From: Andrew Morton <akpm@linux-foundation.org> > Subject: mm-add-apply_to_existing_pages-helper-fix > > reduce code duplication > > Cc: Daniel Axtens <dja@axtens.net> > Cc: Alexander Potapenko <glider@google.com> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Qian Cai <cai@lca.pw> > Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > mm/memory.c | 43 +++++++++++++++++-------------------------- > 1 file changed, 17 insertions(+), 26 deletions(-) > > --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix > +++ a/mm/memory.c > @@ -2141,12 +2141,9 @@ static int apply_to_p4d_range(struct mm_ > return err; > } > > -/* > - * Scan a region of virtual memory, filling in page tables as necessary > - * and calling a provided function on each leaf page table. > - */ > -int apply_to_page_range(struct mm_struct *mm, unsigned long addr, > - unsigned long size, pte_fn_t fn, void *data) > +static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr, > + unsigned long size, pte_fn_t fn, > + void *data, bool create) > { > pgd_t *pgd; > unsigned long next; > @@ -2159,13 +2156,25 @@ int apply_to_page_range(struct mm_struct > pgd = pgd_offset(mm, addr); > do { > next = pgd_addr_end(addr, end); > - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, true); > + if (!create && pgd_none_or_clear_bad(pgd)) > + continue; > + err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, create); > if (err) > break; > } while (pgd++, addr = next, addr != end); > > return err; > } > + > +/* > + * Scan a region of virtual memory, filling in page tables as necessary > + * and calling a provided function on each leaf page table. > + */ > +int apply_to_page_range(struct mm_struct *mm, unsigned long addr, > + unsigned long size, pte_fn_t fn, void *data) > +{ > + return __apply_to_page_range(mm, addr, size, fn, data, true); > +} > EXPORT_SYMBOL_GPL(apply_to_page_range); > > /* > @@ -2178,25 +2187,7 @@ EXPORT_SYMBOL_GPL(apply_to_page_range); > int apply_to_existing_pages(struct mm_struct *mm, unsigned long addr, > unsigned long size, pte_fn_t fn, void *data) > { > - pgd_t *pgd; > - unsigned long next; > - unsigned long end = addr + size; > - int err = 0; > - > - if (WARN_ON(addr >= end)) > - return -EINVAL; > - > - pgd = pgd_offset(mm, addr); > - do { > - next = pgd_addr_end(addr, end); > - if (pgd_none_or_clear_bad(pgd)) > - continue; > - err = apply_to_p4d_range(mm, pgd, addr, next, fn, data, false); > - if (err) > - break; > - } while (pgd++, addr = next, addr != end); > - > - return err; > + return __apply_to_page_range(mm, addr, size, fn, data, false); > } > EXPORT_SYMBOL_GPL(apply_to_existing_pages); > > _ > > > From: Andrew Morton <akpm@linux-foundation.org> > Subject: mm-add-apply_to_existing_pages-helper-fix-fix > > s/apply_to_existing_pages/apply_to_existing_page_range/ > > Cc: Daniel Axtens <dja@axtens.net> > Cc: Alexander Potapenko <glider@google.com> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Qian Cai <cai@lca.pw> > Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > include/linux/mm.h | 6 +++--- > mm/memory.c | 6 +++--- > 2 files changed, 6 insertions(+), 6 deletions(-) > > --- a/include/linux/mm.h~mm-add-apply_to_existing_pages-helper-fix-fix > +++ a/include/linux/mm.h > @@ -2621,9 +2621,9 @@ static inline int vm_fault_to_errno(vm_f > typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); > extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, > unsigned long size, pte_fn_t fn, void *data); > -extern int apply_to_existing_pages(struct mm_struct *mm, unsigned long address, > - unsigned long size, pte_fn_t fn, > - void *data); > +extern int apply_to_existing_page_range(struct mm_struct *mm, > + unsigned long address, unsigned long size, > + pte_fn_t fn, void *data); > > #ifdef CONFIG_PAGE_POISONING > extern bool page_poisoning_enabled(void); > --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix-fix > +++ a/mm/memory.c > @@ -2184,12 +2184,12 @@ EXPORT_SYMBOL_GPL(apply_to_page_range); > * Unlike apply_to_page_range, this does _not_ fill in page tables > * where they are absent. > */ > -int apply_to_existing_pages(struct mm_struct *mm, unsigned long addr, > - unsigned long size, pte_fn_t fn, void *data) > +int apply_to_existing_page_range(struct mm_struct *mm, unsigned long addr, > + unsigned long size, pte_fn_t fn, void *data) > { > return __apply_to_page_range(mm, addr, size, fn, data, false); > } > -EXPORT_SYMBOL_GPL(apply_to_existing_pages); > +EXPORT_SYMBOL_GPL(apply_to_existing_page_range); > > /* > * handle_pte_fault chooses page fault handler according to an entry which was > _ > > From: Andrew Morton <akpm@linux-foundation.org> > Subject: mm-add-apply_to_existing_pages-helper-fix-fix-fix > > initialize __apply_to_page_range::err > > Cc: Alexander Potapenko <glider@google.com> > Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> > Cc: Daniel Axtens <dja@axtens.net> > Cc: Dmitry Vyukov <dvyukov@google.com> > Cc: Qian Cai <cai@lca.pw> > Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org> > --- > > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > --- a/mm/memory.c~mm-add-apply_to_existing_pages-helper-fix-fix-fix > +++ a/mm/memory.c > @@ -2148,7 +2148,7 @@ static int __apply_to_page_range(struct > pgd_t *pgd; > unsigned long next; > unsigned long end = addr + size; > - int err; > + int err = 0; > > if (WARN_ON(addr >= end)) > return -EINVAL; > _ ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-12-13 2:04 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-12-12 9:29 [bug report] mm-add-apply_to_existing_pages-helper-fix Dan Carpenter 2019-12-13 1:03 ` Andrew Morton 2019-12-13 2:04 ` Daniel Axtens
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