SEA exceptions are often caused by an uncorrected hardware
error, and are handled when data abort and instruction abort
exception classes have specific values for their Fault Status
Code.
When SEA occurs, before killing the process, report the error
in the kernel logs.
Update fault_info[] with specific SEA faults so that the
new SEA handler is used.

Signed-off-by: Tyler Baicar <tbai...@codeaurora.org>
CC: Jonathan (Zhixiong) Zhang <zjzh...@codeaurora.org>
Reviewed-by: James Morse <james.mo...@arm.com>
Acked-by: Catalin Marinas <catalin.mari...@arm.com>
---
 arch/arm64/include/asm/esr.h |  1 +
 arch/arm64/mm/fault.c        | 45 ++++++++++++++++++++++++++++++++++----------
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 85997c0..28bf02e 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -83,6 +83,7 @@
 #define ESR_ELx_WNR            (UL(1) << 6)
 
 /* Shared ISS field definitions for Data/Instruction aborts */
+#define ESR_ELx_FnV            (UL(1) << 10)
 #define ESR_ELx_EA             (UL(1) << 9)
 #define ESR_ELx_S1PTW          (UL(1) << 7)
 
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 37b95df..6697816 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -522,6 +522,31 @@ static int do_bad(unsigned long addr, unsigned int esr, 
struct pt_regs *regs)
        return 1;
 }
 
+/*
+ * This abort handler deals with Synchronous External Abort.
+ * It calls notifiers, and then returns "fault".
+ */
+static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs)
+{
+       struct siginfo info;
+       const struct fault_info *inf;
+
+       inf = esr_to_fault_info(esr);
+       pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n",
+               inf->name, esr, addr);
+
+       info.si_signo = SIGBUS;
+       info.si_errno = 0;
+       info.si_code  = 0;
+       if (esr & ESR_ELx_FnV)
+               info.si_addr = 0;
+       else
+               info.si_addr  = (void __user *)addr;
+       arm64_notify_die("", regs, &info, esr);
+
+       return 0;
+}
+
 static const struct fault_info fault_info[] = {
        { do_bad,               SIGBUS,  0,             "ttbr address size 
fault"       },
        { do_bad,               SIGBUS,  0,             "level 1 address size 
fault"    },
@@ -539,22 +564,22 @@ static int do_bad(unsigned long addr, unsigned int esr, 
struct pt_regs *regs)
        { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 1 permission 
fault"      },
        { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 2 permission 
fault"      },
        { do_page_fault,        SIGSEGV, SEGV_ACCERR,   "level 3 permission 
fault"      },
-       { do_bad,               SIGBUS,  0,             "synchronous external 
abort"    },
+       { do_sea,               SIGBUS,  0,             "synchronous external 
abort"    },
        { do_bad,               SIGBUS,  0,             "unknown 17"            
        },
        { do_bad,               SIGBUS,  0,             "unknown 18"            
        },
        { do_bad,               SIGBUS,  0,             "unknown 19"            
        },
-       { do_bad,               SIGBUS,  0,             "synchronous external 
abort (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous external 
abort (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous external 
abort (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous external 
abort (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous parity 
error"      },
+       { do_sea,               SIGBUS,  0,             "level 0 (translation 
table walk)"      },
+       { do_sea,               SIGBUS,  0,             "level 1 (translation 
table walk)"      },
+       { do_sea,               SIGBUS,  0,             "level 2 (translation 
table walk)"      },
+       { do_sea,               SIGBUS,  0,             "level 3 (translation 
table walk)"      },
+       { do_sea,               SIGBUS,  0,             "synchronous parity or 
ECC error" },
        { do_bad,               SIGBUS,  0,             "unknown 25"            
        },
        { do_bad,               SIGBUS,  0,             "unknown 26"            
        },
        { do_bad,               SIGBUS,  0,             "unknown 27"            
        },
-       { do_bad,               SIGBUS,  0,             "synchronous parity 
error (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous parity 
error (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous parity 
error (translation table walk)" },
-       { do_bad,               SIGBUS,  0,             "synchronous parity 
error (translation table walk)" },
+       { do_sea,               SIGBUS,  0,             "level 0 synchronous 
parity error (translation table walk)"     },
+       { do_sea,               SIGBUS,  0,             "level 1 synchronous 
parity error (translation table walk)"     },
+       { do_sea,               SIGBUS,  0,             "level 2 synchronous 
parity error (translation table walk)"     },
+       { do_sea,               SIGBUS,  0,             "level 3 synchronous 
parity error (translation table walk)"     },
        { do_bad,               SIGBUS,  0,             "unknown 32"            
        },
        { do_alignment_fault,   SIGBUS,  BUS_ADRALN,    "alignment fault"       
        },
        { do_bad,               SIGBUS,  0,             "unknown 34"            
        },
-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm 
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.

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