lkml.org 
[lkml]   [2019]   [Aug]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v8 3/7] powerpc/mce: Fix MCE handling for huge pages
Date
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>
---
arch/powerpc/include/asm/mce.h | 2 +-
arch/powerpc/kernel/mce_power.c | 50 ++++++++++++++--------------
arch/powerpc/platforms/pseries/ras.c | 9 ++---
3 files changed, 29 insertions(+), 32 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..bed38a8e2e50 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;
}

/* flush SLBs and reload */
@@ -354,18 +362,16 @@ static int mce_find_instr_ea_and_pfn(struct pt_regs *regs, uint64_t *addr,
* faults
*/
int instr;
- unsigned long pfn, instr_addr;
+ unsigned long instr_addr;
struct instruction_op op;
struct pt_regs tmp = *regs;

- pfn = addr_to_pfn(regs, regs->nip);
- if (pfn != ULONG_MAX) {
- instr_addr = (pfn << PAGE_SHIFT) + (regs->nip & ~PAGE_MASK);
+ instr_addr = addr_to_phys(regs, regs->nip) + (regs->nip & ~PAGE_MASK);
+ if (instr_addr != ULONG_MAX) {
instr = *(unsigned int *)(instr_addr);
if (!analyse_instr(&op, &tmp, instr)) {
- pfn = addr_to_pfn(regs, op.ea);
*addr = op.ea;
- *phys_addr = (pfn << PAGE_SHIFT);
+ *phys_addr = addr_to_phys(regs, op.ea);
return 0;
}
/*
@@ -440,15 +446,9 @@ static int mce_handle_ierror(struct pt_regs *regs,
*addr = regs->nip;
if (mce_err->sync_error &&
table[i].error_type == MCE_ERROR_TYPE_UE) {
- unsigned long pfn;
-
- if (get_paca()->in_mce < MAX_MCE_DEPTH) {
- pfn = addr_to_pfn(regs, regs->nip);
- if (pfn != ULONG_MAX) {
- *phys_addr =
- (pfn << PAGE_SHIFT);
- }
- }
+ if (get_paca()->in_mce < MAX_MCE_DEPTH)
+ *phys_addr = addr_to_phys(regs,
+ regs->nip);
}
}
return handled;
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index f16fdd0f71f7..5743f6353638 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -739,13 +739,10 @@ static void pseries_do_memory_failure(struct pt_regs *regs,
if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
paddr = be64_to_cpu(mce_log->logical_address);
} else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
- unsigned long pfn;
-
- pfn = addr_to_pfn(regs,
- be64_to_cpu(mce_log->effective_address));
- if (pfn == ULONG_MAX)
+ paddr = addr_to_phys(regs,
+ be64_to_cpu(mce_log->effective_address));
+ if (paddr == ULONG_MAX)
return;
- paddr = pfn << PAGE_SHIFT;
} else {
return;
}
--
2.20.1
\
 
 \ /
  Last update: 2019-08-07 16:58    [W:0.103 / U:3.040 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site