Merge tag 'mips-fixes_6.18_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS fix from Thomas Bogendoerfer:
 "Fix TLB unification for cores with more than 64 TLB entries"

* tag 'mips-fixes_6.18_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow
This commit is contained in:
Linus Torvalds
2025-11-29 15:15:14 -08:00

View File

@@ -12,6 +12,7 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/smp.h> #include <linux/smp.h>
#include <linux/memblock.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/hugetlb.h> #include <linux/hugetlb.h>
#include <linux/export.h> #include <linux/export.h>
@@ -522,17 +523,26 @@ static int r4k_vpn_cmp(const void *a, const void *b)
* Initialise all TLB entries with unique values that do not clash with * Initialise all TLB entries with unique values that do not clash with
* what we have been handed over and what we'll be using ourselves. * what we have been handed over and what we'll be using ourselves.
*/ */
static void r4k_tlb_uniquify(void) static void __ref r4k_tlb_uniquify(void)
{ {
unsigned long tlb_vpns[1 << MIPS_CONF1_TLBS_SIZE];
int tlbsize = current_cpu_data.tlbsize; int tlbsize = current_cpu_data.tlbsize;
bool use_slab = slab_is_available();
int start = num_wired_entries(); int start = num_wired_entries();
phys_addr_t tlb_vpn_size;
unsigned long *tlb_vpns;
unsigned long vpn_mask; unsigned long vpn_mask;
int cnt, ent, idx, i; int cnt, ent, idx, i;
vpn_mask = GENMASK(cpu_vmbits - 1, 13); vpn_mask = GENMASK(cpu_vmbits - 1, 13);
vpn_mask |= IS_ENABLED(CONFIG_64BIT) ? 3ULL << 62 : 1 << 31; vpn_mask |= IS_ENABLED(CONFIG_64BIT) ? 3ULL << 62 : 1 << 31;
tlb_vpn_size = tlbsize * sizeof(*tlb_vpns);
tlb_vpns = (use_slab ?
kmalloc(tlb_vpn_size, GFP_KERNEL) :
memblock_alloc_raw(tlb_vpn_size, sizeof(*tlb_vpns)));
if (WARN_ON(!tlb_vpns))
return; /* Pray local_flush_tlb_all() is good enough. */
htw_stop(); htw_stop();
for (i = start, cnt = 0; i < tlbsize; i++, cnt++) { for (i = start, cnt = 0; i < tlbsize; i++, cnt++) {
@@ -585,6 +595,10 @@ static void r4k_tlb_uniquify(void)
tlbw_use_hazard(); tlbw_use_hazard();
htw_start(); htw_start();
flush_micro_tlb(); flush_micro_tlb();
if (use_slab)
kfree(tlb_vpns);
else
memblock_free(tlb_vpns, tlb_vpn_size);
} }
/* /*