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| author | Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2025-11-28 19:53:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-12-07 00:18:51 +0300 |
| commit | 231ac951fabae2aaed8b2c00b4a097107be49c8c (patch) | |
| tree | 6a74e2396f7c1b882cb16f0ccd00b1dc9cd8e200 | |
| parent | 135713cd0751bf296e515f5fdec234320f73bbd8 (diff) | |
| download | linux-231ac951fabae2aaed8b2c00b4a097107be49c8c.tar.xz | |
MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow
commit 841ecc979b18d3227fad5e2d6a1e6f92688776b5 upstream.
Owing to Config4.MMUSizeExt and VTLB/FTLB MMU features later MIPSr2+
cores can have more than 64 TLB entries. Therefore allocate an array
for uniquification instead of placing too an small array on the stack.
Fixes: 35ad7e181541 ("MIPS: mm: tlb-r4k: Uniquify TLB entries on init")
Co-developed-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v6.17+: 9f048fa48740: MIPS: mm: Prevent a TLB shutdown on initial uniquification
Cc: stable@vger.kernel.org # v6.17+
Tested-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Tested-by: Klara Modin <klarasmodin@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/mips/mm/tlb-r4k.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c index 19956b7c4b12..06cb140476ea 100644 --- a/arch/mips/mm/tlb-r4k.c +++ b/arch/mips/mm/tlb-r4k.c @@ -12,6 +12,7 @@ #include <linux/init.h> #include <linux/sched.h> #include <linux/smp.h> +#include <linux/memblock.h> #include <linux/mm.h> #include <linux/hugetlb.h> #include <linux/export.h> @@ -520,17 +521,26 @@ static int r4k_vpn_cmp(const void *a, const void *b) * 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. */ -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; + bool use_slab = slab_is_available(); int start = num_wired_entries(); + phys_addr_t tlb_vpn_size; + unsigned long *tlb_vpns; unsigned long vpn_mask; int cnt, ent, idx, i; vpn_mask = GENMASK(cpu_vmbits - 1, 13); 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(); for (i = start, cnt = 0; i < tlbsize; i++, cnt++) { @@ -583,6 +593,10 @@ static void r4k_tlb_uniquify(void) tlbw_use_hazard(); htw_start(); flush_micro_tlb(); + if (use_slab) + kfree(tlb_vpns); + else + memblock_free(tlb_vpns, tlb_vpn_size); } /* |