[adding the stable team]

On 05.02.24 18:07, Yang Shi wrote:

On Sat, Feb 3, 2024 at 1:24 AM Thorsten Leemhuis regressions@leemhuis.info wrote:

...

On 18.01.24 14:35, Yang Shi wrote:

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The commit efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") caused two issues [1] [2] reported on 32 bit system or compat userspace.

It doesn't make too much sense to force huge page alignment on 32 bit system due to the constrained virtual address space.

[1] https://lore.kernel.org/linux-mm/CAHbLzkqa1SCBA10yjWTtA2mKCsoK5+M1BthSDL8ROv... [2] https://lore.kernel.org/linux-mm/CAHbLzkqa1SCBA10yjWTtA2mKCsoK5+M1BthSDL8ROv...

[FWIW, this is now 4ef9ad19e17676 ("mm: huge_memory: don't force huge page alignment on 32 bit") in mainline]

Quick question: it it okay to ask Greg to pick this up for linux-6.7.y series?

Yes, definitely. Thanks for following up.

In that case: Greg, could you please consider picking up 4ef9ad19e17676 ("mm: huge_memory: don't force huge page alignment on 32 bit") for the next linux-6.7 rc round? tia!

Ohh, and btw: you might also want to pick up c4608d1bf7c653 ("mm: mmap: map MAP_STACK to VM_NOHUGEPAGE") if you haven't already done so: its stable tag contains a typo, hence I guess your scripts might have missed it (I only noticed that by chance).

Ciao, Thorsten

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I'm wondering because Jiri's report ([1] in above quote) sounded like this is something that will affect and annoy quite a few people with the linux-6.7.y.

Ciao, Thorsten

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Fixes: efa7df3e3bb5 ("mm: align larger anonymous mappings on THP boundaries") Reported-by: Jiri Slaby jirislaby@kernel.org Reported-by: Suren Baghdasaryan surenb@google.com Tested-by: Jiri Slaby jirislaby@kernel.org Tested-by: Suren Baghdasaryan surenb@google.com Cc: Rik van Riel riel@surriel.com Cc: Matthew Wilcox willy@infradead.org Cc: Christopher Lameter cl@linux.com Signed-off-by: Yang Shi yang@os.amperecomputing.com

---

mm/huge_memory.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94ef5c02b459..e9fbaccbe0c0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -37,6 +37,7 @@ #include <linux/page_owner.h> #include <linux/sched/sysctl.h> #include <linux/memory-tiers.h> +#include <linux/compat.h>

#include <asm/tlb.h> #include <asm/pgalloc.h> @@ -811,6 +812,14 @@ static unsigned long __thp_get_unmapped_area(struct file *filp, loff_t off_align = round_up(off, size); unsigned long len_pad, ret;

• /*
  

•  * It doesn't make too much sense to froce huge page alignment on
  

•  * 32 bit system or compat userspace due to the contrained virtual
  

•  * address space and address entropy.
  

•  */
  

• if (IS_ENABLED(CONFIG_32BIT) || in_compat_syscall())
  

•         return 0;
  

• if (off_end <= off_align || (off_end - off_align) < size)
          return 0;