From ee6eeeb88e799abd4e3ba42063b97786a212428e Mon Sep 17 00:00:00 2001 From: Balbir Singh Date: Tue, 20 Aug 2019 13:43:47 +0530 Subject: [PATCH] powerpc/mce: Fix MCE handling for huge pages commit 99ead78afd1128bfcebe7f88f3b102fb2da09aee upstream. The current code would fail on huge pages addresses, since the shift would be incorrect. Use the correct page shift value returned by __find_linux_pte() to get the correct physical address. The code is more generic and can handle both regular and compound pages. Fixes: ba41e1e1ccb9 ("powerpc/mce: Hookup derror (load/store) UE errors") Signed-off-by: Balbir Singh [arbab@linux.ibm.com: Fixup pseries_do_memory_failure()] Signed-off-by: Reza Arbab Tested-by: Mahesh Salgaonkar Signed-off-by: Santosh Sivaraj Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190820081352.8641-3-santosh@fossix.org Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/mce_power.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c index 3022d67f0c48..37a110b8e7e1 100644 --- a/arch/powerpc/kernel/mce_power.c +++ b/arch/powerpc/kernel/mce_power.c @@ -39,6 +39,7 @@ static unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr) { pte_t *ptep; + unsigned int shift; unsigned long flags; struct mm_struct *mm; @@ -48,13 +49,18 @@ static unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr) mm = &init_mm; local_irq_save(flags); - if (mm == current->mm) - ptep = find_current_mm_pte(mm->pgd, addr, NULL, NULL); - else - ptep = find_init_mm_pte(addr, NULL); + ptep = __find_linux_pte(mm->pgd, addr, NULL, &shift); local_irq_restore(flags); + if (!ptep || pte_special(*ptep)) return ULONG_MAX; + + if (shift > PAGE_SHIFT) { + unsigned long rpnmask = (1ul << shift) - PAGE_SIZE; + + return pte_pfn(__pte(pte_val(*ptep) | (addr & rpnmask))); + } + return pte_pfn(*ptep); } @@ -339,7 +345,7 @@ static const struct mce_derror_table mce_p9_derror_table[] = { MCE_INITIATOR_CPU, MCE_SEV_ERROR_SYNC, }, { 0, false, 0, 0, 0, 0 } }; -static int mce_find_instr_ea_and_pfn(struct pt_regs *regs, uint64_t *addr, +static int mce_find_instr_ea_and_phys(struct pt_regs *regs, uint64_t *addr, uint64_t *phys_addr) { /* @@ -530,7 +536,8 @@ static int mce_handle_derror(struct pt_regs *regs, * kernel/exception-64s.h */ if (get_paca()->in_mce < MAX_MCE_DEPTH) - mce_find_instr_ea_and_pfn(regs, addr, phys_addr); + mce_find_instr_ea_and_phys(regs, addr, + phys_addr); } found = 1; }