[Crash-utility] [PATCH 1/5] LoongArch64: Fix CPU registers reading from dump notes
LoongArch stores the register set exported in NT_PRSTATUS as an
elf_gregset_t. The special registers are laid out as orig_a0, csr_era,
csr_badvaddr, csr_crmd, csr_prmd, csr_euen, csr_ecfg and csr_estat
after the 32 GPRs.
The old crash-local register layout put csr_crmd at the first
special-register slot and placed epc near the end. That made help -r
and active-task unwinding read nonsensical CSR values from dump notes.
Match the local register structure and indexes to the kernel
pt_regs/elf_gregset_t layout. Also handle modern kernels where
crash_notes may refer to the per-cpu note storage directly, and use
NETDUMP ELF notes for libvirt/QEMU dump files when crash_notes does not
provide usable data.
Signed-off-by: Ming Wang <wangming01(a)loongson.cn>
---
loongarch64.c | 38 +++++++++++++++++++++++---------------
1 file changed, 23 insertions(+), 15 deletions(-)
diff --git a/loongarch64.c b/loongarch64.c
index 6437c4aa4656..5adb7d8038db 100644
--- a/loongarch64.c
+++ b/loongarch64.c
@@ -18,20 +18,23 @@
#include <elf.h>
#include "defs.h"
-/* from arch/loongarch/include/asm/ptrace.h */
+/*
+ * This matches the beginning of both kernel struct pt_regs and the
+ * elf_gregset_t layout exported in NT_PRSTATUS notes.
+ */
struct loongarch64_pt_regs {
/* Saved main processor registers. */
unsigned long regs[32];
/* Saved special registers. */
+ unsigned long orig_a0;
+ unsigned long csr_epc;
+ unsigned long csr_badvaddr;
unsigned long csr_crmd;
unsigned long csr_prmd;
unsigned long csr_euen;
unsigned long csr_ecfg;
unsigned long csr_estat;
- unsigned long csr_epc;
- unsigned long csr_badvaddr;
- unsigned long orig_a0;
};
struct loongarch64_unwind_frame {
@@ -108,13 +111,14 @@ typedef struct { ulong pte; } pte_t;
#define LOONGARCH64_EF_RA 1
#define LOONGARCH64_EF_SP 3
#define LOONGARCH64_EF_FP 22
-#define LOONGARCH64_EF_CSR_EPC 32
-#define LOONGARCH64_EF_CSR_BADVADDR 33
-#define LOONGARCH64_EF_CSR_CRMD 34
-#define LOONGARCH64_EF_CSR_PRMD 35
-#define LOONGARCH64_EF_CSR_EUEN 36
-#define LOONGARCH64_EF_CSR_ECFG 37
-#define LOONGARCH64_EF_CSR_ESTAT 38
+#define LOONGARCH64_EF_ORIG_A0 32
+#define LOONGARCH64_EF_CSR_EPC 33
+#define LOONGARCH64_EF_CSR_BADVADDR 34
+#define LOONGARCH64_EF_CSR_CRMD 35
+#define LOONGARCH64_EF_CSR_PRMD 36
+#define LOONGARCH64_EF_CSR_EUEN 37
+#define LOONGARCH64_EF_CSR_ECFG 38
+#define LOONGARCH64_EF_CSR_ESTAT 39
static struct machine_specific loongarch64_machine_specific = { 0 };
@@ -911,8 +915,12 @@ loongarch64_get_crash_notes(void)
/*
* Add __per_cpu_offset for each cpu to form the pointer to the notes
*/
- for (i = 0; i < kt->cpus; i++)
- notes_ptrs[i] = notes_ptrs[kt->cpus-1] + kt->__per_cpu_offset[i];
+ for (i = 0; i < kt->cpus; i++) {
+ if (IS_KVADDR(notes_ptrs[kt->cpus-1]))
+ notes_ptrs[i] = notes_ptrs[kt->cpus-1] + kt->__per_cpu_offset[i];
+ else
+ notes_ptrs[i] = crash_notes + kt->__per_cpu_offset[i];
+ }
}
buf = GETBUF(SIZE(note_buf));
@@ -1009,7 +1017,7 @@ loongarch64_get_elf_notes(void)
struct machine_specific *ms = machdep->machspec;
int i;
- if (!DISKDUMP_DUMPFILE() && !KDUMP_DUMPFILE())
+ if (!DISKDUMP_DUMPFILE() && !KDUMP_DUMPFILE() && !NETDUMP_DUMPFILE())
return FALSE;
panic_task_regs = calloc(kt->cpus, sizeof(*panic_task_regs));
@@ -1022,7 +1030,7 @@ loongarch64_get_elf_notes(void)
if (DISKDUMP_DUMPFILE())
note = diskdump_get_prstatus_percpu(i);
- else if (KDUMP_DUMPFILE())
+ else if (KDUMP_DUMPFILE() || NETDUMP_DUMPFILE())
note = netdump_get_prstatus_percpu(i);
if (!note) {
--
2.43.0