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authorIngo Molnar <mingo@kernel.org>2024-03-25 11:47:51 +0100
committerIngo Molnar <mingo@kernel.org>2024-03-25 11:54:35 +0100
commitc567f2948f57bdc03ed03403ae0234085f376b7d (patch)
treec77676f421fbfe2cbb946bdb3a439f51202214a8 /arch
parentDocumentation/x86: Fix title underline length (diff)
downloadlinux-c567f2948f57bdc03ed03403ae0234085f376b7d.tar.xz
linux-c567f2948f57bdc03ed03403ae0234085f376b7d.zip
Revert "x86/mm/ident_map: Use gbpages only where full GB page should be mapped."
This reverts commit d794734c9bbfe22f86686dc2909c25f5ffe1a572. While the original change tries to fix a bug, it also unintentionally broke existing systems, see the regressions reported at: https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/ Since d794734c9bbf was also marked for -stable, let's back it out before causing more damage. Note that due to another upstream change the revert was not 100% automatic: 0a845e0f6348 mm/treewide: replace pud_large() with pud_leaf() Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Cc: Russ Anderson <rja@hpe.com> Cc: Steve Wahl <steve.wahl@hpe.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/all/3a1b9909-45ac-4f97-ad68-d16ef1ce99db@pavinjoseph.com/ Fixes: d794734c9bbf ("x86/mm/ident_map: Use gbpages only where full GB page should be mapped.")
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/mm/ident_map.c23
1 files changed, 5 insertions, 18 deletions
diff --git a/arch/x86/mm/ident_map.c b/arch/x86/mm/ident_map.c
index a204a332c71f..968d7005f4a7 100644
--- a/arch/x86/mm/ident_map.c
+++ b/arch/x86/mm/ident_map.c
@@ -26,31 +26,18 @@ static int ident_pud_init(struct x86_mapping_info *info, pud_t *pud_page,
for (; addr < end; addr = next) {
pud_t *pud = pud_page + pud_index(addr);
pmd_t *pmd;
- bool use_gbpage;
next = (addr & PUD_MASK) + PUD_SIZE;
if (next > end)
next = end;
- /* if this is already a gbpage, this portion is already mapped */
- if (pud_leaf(*pud))
- continue;
-
- /* Is using a gbpage allowed? */
- use_gbpage = info->direct_gbpages;
-
- /* Don't use gbpage if it maps more than the requested region. */
- /* at the begining: */
- use_gbpage &= ((addr & ~PUD_MASK) == 0);
- /* ... or at the end: */
- use_gbpage &= ((next & ~PUD_MASK) == 0);
-
- /* Never overwrite existing mappings */
- use_gbpage &= !pud_present(*pud);
-
- if (use_gbpage) {
+ if (info->direct_gbpages) {
pud_t pudval;
+ if (pud_present(*pud))
+ continue;
+
+ addr &= PUD_MASK;
pudval = __pud((addr - info->offset) | info->page_flag);
set_pud(pud, pudval);
continue;