[PATCH] mm, gup: fix typo in gup_p4d_range()

[PATCH] mm, gup: fix typo in gup_p4d_range()

[Kirill A. Shutemov]

gup_p4d_range() should call gup_pud_range(), not itself.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")
---
 mm/gup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/gup.c b/mm/gup.c
index c74bad1bf6e8..04aa405350dc 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1455,7 +1455,7 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
 			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
 					 P4D_SHIFT, next, write, pages, nr))
 				return 0;
-		} else if (!gup_p4d_range(p4d, addr, next, write, pages, nr))
+		} else if (!gup_pud_range(p4d, addr, next, write, pages, nr))
 			return 0;
 	} while (p4dp++, addr = next, addr != end);
 
-- 
2.11.0

Re: [PATCH] mm, gup: fix typo in gup_p4d_range()

[Michal Hocko]

On Mon 13-03-17 08:22:13, Kirill A. Shutemov wrote:
> gup_p4d_range() should call gup_pud_range(), not itself.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")

Upps, missed this one during the review. Thanks for catching that up

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  mm/gup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index c74bad1bf6e8..04aa405350dc 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1455,7 +1455,7 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
>  			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
>  					 P4D_SHIFT, next, write, pages, nr))
>  				return 0;
> -		} else if (!gup_p4d_range(p4d, addr, next, write, pages, nr))
> +		} else if (!gup_pud_range(p4d, addr, next, write, pages, nr))
>  			return 0;
>  	} while (p4dp++, addr = next, addr != end);
>  
> -- 
> 2.11.0
> 

-- 
Michal Hocko
SUSE Labs

Re: [PATCH] mm, gup: fix typo in gup_p4d_range()

[Mark Rutland]

On Mon, Mar 13, 2017 at 08:22:13AM +0300, Kirill A. Shutemov wrote:
> gup_p4d_range() should call gup_pud_range(), not itself.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")
> ---
>  mm/gup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index c74bad1bf6e8..04aa405350dc 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1455,7 +1455,7 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
>  			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
>  					 P4D_SHIFT, next, write, pages, nr))
>  				return 0;
> -		} else if (!gup_p4d_range(p4d, addr, next, write, pages, nr))
> +		} else if (!gup_pud_range(p4d, addr, next, write, pages, nr))
>  			return 0;
>  	} while (p4dp++, addr = next, addr != end);

I just hit this on arm64, where the compiler was nice enough to warn me
that something was amiss:

mm/gup.c:1412:12: warning: 'gup_pud_range' defined but not used [-Wunused-function]
 static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
            ^

FWIW:

Acked-by: Mark Rutland <mark.rutland@arm.com>

Mark.

Re: [PATCH] mm, gup: fix typo in gup_p4d_range()

[Chris Packham]

On 13/03/17 18:22, Kirill A. Shutemov wrote:
> gup_p4d_range() should call gup_pud_range(), not itself.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")
> ---
>  mm/gup.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/gup.c b/mm/gup.c
> index c74bad1bf6e8..04aa405350dc 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -1455,7 +1455,7 @@ static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
>  			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
>  					 P4D_SHIFT, next, write, pages, nr))
>  				return 0;
> -		} else if (!gup_p4d_range(p4d, addr, next, write, pages, nr))
> +		} else if (!gup_pud_range(p4d, addr, next, write, pages, nr))
>  			return 0;
>  	} while (p4dp++, addr = next, addr != end);

Fixes the build issue for me. Thanks.

Re: [PATCH] mm, gup: fix typo in gup_p4d_range()

[Geert Uytterhoeven]

Hi Kirill,

On Mon, Mar 13, 2017 at 6:22 AM, Kirill A. Shutemov
<kirill.shutemov@linux.intel.com> wrote:
> gup_p4d_range() should call gup_pud_range(), not itself.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Reported-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> Fixes: c2febafc6773 ("mm: convert generic code to 5-level paging")

FTR, this (now commit ce70df089143c493) fixes the strange crashes I saw
with plain v4.11-rc2 and renesas-devel-20170313-v4.11-rc2 during shutdown on
Renesas R-Car Gen2 (arm) and R-Car Gen3 (arm64) (but not on older
SH/R-Mobile), and that I bisected to commit c2febafc6773.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds