[PATCH] arm64: mm: print hexadecimal EC value in mem_abort_decode()

Miles Chen miles.chen at mediatek.com
Tue Aug 6 04:29:48 PDT 2019


This change prints the hexadecimal EC value in mem_abort_decode(),
which makes it easier to lookup the corresponding EC in
the ARM Architecture Reference Manual.

The commit 1f9b8936f36f ("arm64: Decode information from ESR upon mem
faults") prints useful information when memory abort occurs. It would
be easier to lookup "0x25" instead of "DABT" in the document. Then we
can check the corresponding ISS.

For example:
Current	info	  	Document
		  	EC	Exception class
"CP15 MCR/MRC"		0x3	"MCR or MRC access to CP15a..."
"ASIMD"			0x7	"Access to SIMD or floating-point..."
"DABT (current EL)" 	0x25	"Data Abort taken without..."
...

Before:
Unable to handle kernel paging request at virtual address 000000000000c000
Mem abort info:
  ESR = 0x96000046
  Exception class = DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000046
  CM = 0, WnR = 1

After:
Unable to handle kernel paging request at virtual address 000000000000c000
Mem abort info:
  ESR = 0x96000046
  EC = 0x25, Exception class = DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
Data abort info:
  ISV = 0, ISS = 0x00000046
  CM = 0, WnR = 1

Cc: Mark Rutland <Mark.rutland at arm.com>
Cc: Anshuman Khandual <anshuman.khandual at arm.com>
Cc: James Morse <james.morse at arm.com>
Signed-off-by: Miles Chen <miles.chen at mediatek.com>
---
 arch/arm64/mm/fault.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index cfd65b63f36f..afb6041e25e6 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -86,8 +86,8 @@ static void mem_abort_decode(unsigned int esr)
 	pr_alert("Mem abort info:\n");
 
 	pr_alert("  ESR = 0x%08x\n", esr);
-	pr_alert("  Exception class = %s, IL = %u bits\n",
-		 esr_get_class_string(esr),
+	pr_alert("  EC = 0x%lx, Exception class = %s, IL = %u bits\n",
+		 ESR_ELx_EC(esr), esr_get_class_string(esr),
 		 (esr & ESR_ELx_IL) ? 32 : 16);
 	pr_alert("  SET = %lu, FnV = %lu\n",
 		 (esr & ESR_ELx_SET_MASK) >> ESR_ELx_SET_SHIFT,
-- 
2.18.0




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