From: Ankur Arora Date: Wed, 28 Jan 2026 18:59:43 +0000 (-0800) Subject: mm: folio_zero_user: open code range computation in folio_zero_user() X-Git-Tag: v7.0-rc1~47^2~33 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3f54ef56fd4540142d2d9a7e7cf0b70dd221c1e1;p=thirdparty%2Fkernel%2Fstable.git mm: folio_zero_user: open code range computation in folio_zero_user() riscv64-gcc-linux-gnu (v8.5) reports a compile time assert in: r[2] = DEFINE_RANGE(clamp_t(s64, fault_idx - radius, pg.start, pg.end), clamp_t(s64, fault_idx + radius, pg.start, pg.end)); where it decides that pg.start > pg.end in: clamp_t(s64, fault_idx + radius, pg.start, pg.end)); where pg comes from: const struct range pg = DEFINE_RANGE(0, folio_nr_pages(folio) - 1); That does not seem like it could be true. Even for pg.start == pg.end, we would need folio_test_large() to evaluate to false at compile time: static inline unsigned long folio_nr_pages(const struct folio *folio) { if (!folio_test_large(folio)) return 1; return folio_large_nr_pages(folio); } Workaround by open coding the range computation. Also, simplify the type declarations for the relevant variables. [ankur.a.arora@oracle.com: remove unneeded cast, per David] Link: https://lkml.kernel.org/r/20260206223801.2617497-1-ankur.a.arora@oracle.com Link: https://lkml.kernel.org/r/20260206223801.2617497-1-ankur.a.arora@oracle.com Link: https://lkml.kernel.org/r/20260128185943.2397128-1-ankur.a.arora@oracle.com Fixes: 93552c9a3350 ("mm: folio_zero_user: cache neighbouring pages") Signed-off-by: Ankur Arora Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202601240453.QCjgGdJa-lkp@intel.com/ Acked-by: David Hildenbrand (Arm) Cc: Andy Lutomirski Cc: "Borislav Petkov (AMD)" Cc: Boris Ostrovsky Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Konrad Rzessutek Wilk Cc: Lance Yang Cc: Li Zhe Cc: Mateusz Guzik Cc: Matthew Wilcox (Oracle) Cc: Peter Zijlstra Cc: Raghavendra K T Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- diff --git a/mm/memory.c b/mm/memory.c index 15a6c09d54ee5..cf32e2666e71b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -7316,7 +7316,7 @@ void folio_zero_user(struct folio *folio, unsigned long addr_hint) const unsigned long base_addr = ALIGN_DOWN(addr_hint, folio_size(folio)); const long fault_idx = (addr_hint - base_addr) / PAGE_SIZE; const struct range pg = DEFINE_RANGE(0, folio_nr_pages(folio) - 1); - const int radius = FOLIO_ZERO_LOCALITY_RADIUS; + const long radius = FOLIO_ZERO_LOCALITY_RADIUS; struct range r[3]; int i; @@ -7324,20 +7324,19 @@ void folio_zero_user(struct folio *folio, unsigned long addr_hint) * Faulting page and its immediate neighbourhood. Will be cleared at the * end to keep its cachelines hot. */ - r[2] = DEFINE_RANGE(clamp_t(s64, fault_idx - radius, pg.start, pg.end), - clamp_t(s64, fault_idx + radius, pg.start, pg.end)); + r[2] = DEFINE_RANGE(fault_idx - radius < (long)pg.start ? pg.start : fault_idx - radius, + fault_idx + radius > (long)pg.end ? pg.end : fault_idx + radius); + /* Region to the left of the fault */ - r[1] = DEFINE_RANGE(pg.start, - clamp_t(s64, r[2].start - 1, pg.start - 1, r[2].start)); + r[1] = DEFINE_RANGE(pg.start, r[2].start - 1); /* Region to the right of the fault: always valid for the common fault_idx=0 case. */ - r[0] = DEFINE_RANGE(clamp_t(s64, r[2].end + 1, r[2].end, pg.end + 1), - pg.end); + r[0] = DEFINE_RANGE(r[2].end + 1, pg.end); for (i = 0; i < ARRAY_SIZE(r); i++) { const unsigned long addr = base_addr + r[i].start * PAGE_SIZE; - const unsigned int nr_pages = range_len(&r[i]); + const long nr_pages = (long)range_len(&r[i]); struct page *page = folio_page(folio, r[i].start); if (nr_pages > 0)