2019-08-08 06:45:37

by Miles Chen

[permalink] [raw]
Subject: [PATCH v3] arm64: mm: print hexadecimal EC value in mem_abort_decode()

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: 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

Change since v1:
print "EC" instead of "Exception class"
print EC in fixwidth

Change since v2:
add acked-by tag from Mark since v2 implemented the suggestion in v1
add reviewed-by tag from Anshuman in v2

Acked-by: Mark Rutland <[email protected]>
Reviewed-by: Anshuman Khandual <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: James Morse <[email protected]>
Signed-off-by: Miles Chen <[email protected]>
---
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..ad4980a27edb 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%02lx: %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