Santosh Sivaraj's on August 15, 2019 10:39 am:
From: Balbir Singh bsingharora@gmail.com
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 bsingharora@gmail.com [arbab@linux.ibm.com: Fixup pseries_do_memory_failure()] Signed-off-by: Reza Arbab arbab@linux.ibm.com Co-developed-by: Santosh Sivaraj santosh@fossix.org Signed-off-by: Santosh Sivaraj santosh@fossix.org Tested-by: Mahesh Salgaonkar mahesh@linux.vnet.ibm.com Cc: stable@vger.kernel.org # v4.15+
arch/powerpc/include/asm/mce.h | 2 +- arch/powerpc/kernel/mce_power.c | 55 ++++++++++++++-------------- arch/powerpc/platforms/pseries/ras.c | 9 ++--- 3 files changed, 32 insertions(+), 34 deletions(-)
diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h index a4c6a74ad2fb..f3a6036b6bc0 100644 --- a/arch/powerpc/include/asm/mce.h +++ b/arch/powerpc/include/asm/mce.h @@ -209,7 +209,7 @@ extern void release_mce_event(void); extern void machine_check_queue_event(void); extern void machine_check_print_event_info(struct machine_check_event *evt, bool user_mode, bool in_guest); -unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr); +unsigned long addr_to_phys(struct pt_regs *regs, unsigned long addr); #ifdef CONFIG_PPC_BOOK3S_64 void flush_and_reload_slb(void); #endif /* CONFIG_PPC_BOOK3S_64 */ diff --git a/arch/powerpc/kernel/mce_power.c b/arch/powerpc/kernel/mce_power.c index a814d2dfb5b0..e74816f045f8 100644 --- a/arch/powerpc/kernel/mce_power.c +++ b/arch/powerpc/kernel/mce_power.c @@ -20,13 +20,14 @@ #include <asm/exception-64s.h> /*
- Convert an address related to an mm to a PFN. NOTE: we are in real
- mode, we could potentially race with page table updates.
- Convert an address related to an mm to a physical address.
*/
- NOTE: we are in real mode, we could potentially race with page table updates.
-unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr) +unsigned long addr_to_phys(struct pt_regs *regs, unsigned long addr) {
- pte_t *ptep;
- unsigned long flags;
- pte_t *ptep, pte;
- unsigned int shift;
- unsigned long flags, phys_addr; struct mm_struct *mm;
if (user_mode(regs)) @@ -35,14 +36,21 @@ 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;
- return pte_pfn(*ptep);
- pte = *ptep;
- if (shift > PAGE_SHIFT) {
unsigned long rpnmask = (1ul << shift) - PAGE_SIZE;pte = __pte(pte_val(pte) | (addr & rpnmask));- }
- phys_addr = pte_pfn(pte) << PAGE_SHIFT;
- return phys_addr;
}
This should remain addr_to_pfn I think. None of the callers care what size page the EA was mapped with. 'pfn' is referring to the Linux pfn, which is the small page number.
if (shift > PAGE_SHIFT) return (pte_pfn(*ptep) | ((addr & ((1UL << shift) - 1)) >> PAGE_SHIFT); else return pte_pfn(*ptep);
Something roughly like that, then you don't have to change any callers or am I missing something?
Thanks, Nick