The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6e866a462867b60841202e900f10936a0478608c Mon Sep 17 00:00:00 2001
From: Helge Deller deller@gmx.de Date: Sun, 31 Oct 2021 21:58:12 +0100 Subject: [PATCH] parisc: Fix set_fixmap() on PA1.x CPUs
Fix a kernel crash which happens on PA1.x CPUs while initializing the FTRACE/KPROBE breakpoints. The PTE table entries for the fixmap area were not created correctly.
Signed-off-by: Helge Deller deller@gmx.de Fixes: ccfbc68d41c2 ("parisc: add set_fixmap()/clear_fixmap()") Cc: stable@vger.kernel.org # v5.2+
diff --git a/arch/parisc/mm/fixmap.c b/arch/parisc/mm/fixmap.c index 24426a7e1a5e..cc15d737fda6 100644 --- a/arch/parisc/mm/fixmap.c +++ b/arch/parisc/mm/fixmap.c @@ -20,12 +20,9 @@ void notrace set_fixmap(enum fixed_addresses idx, phys_addr_t phys) pte_t *pte;
if (pmd_none(*pmd)) - pmd = pmd_alloc(NULL, pud, vaddr); - - pte = pte_offset_kernel(pmd, vaddr); - if (pte_none(*pte)) pte = pte_alloc_kernel(pmd, vaddr);
+ pte = pte_offset_kernel(pmd, vaddr); set_pte_at(&init_mm, vaddr, pte, __mk_pte(phys, PAGE_KERNEL_RWX)); flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); }