[Crash-utility] [PATCH crash-trace] Fix handling of Thumb-2 kernels
The function pointer to symbol comparison for checking get_fields fails
with ARM kernels built with the Thumb-2 instruction set. Ignore the
least significant bit for the comparison since it stores information
about the ARM/Thumb state. Do this unconditionally since it shouldn't
cause any problems for other architectures.
crash-arm> extend trace.so
...
<readmem: 80d57cbc, KVADDR, "read ftrace_event_call get_fields", 4, (ROE),
ff87ffa4>
<read_kdump: addr: 80d57cbc paddr: d57cbc cnt: 4>
Unkown get_fields function
extend: /usr/lib/crash-arm/extensions/trace.so: no commands registered: shared object
unloaded
crash-arm> rd 80d57cbc
80d57cbc: 801db565 e...
crash-arm> sym syscall_get_enter_fields
801db564 (t) syscall_get_enter_fields
Signed-off-by: Vincent Whitchurch <vincent.whitchurch(a)axis.com>
---
trace.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/trace.c b/trace.c
index c33907f..bdb086a 100644
--- a/trace.c
+++ b/trace.c
@@ -1029,9 +1029,9 @@ int ftrace_get_event_type_fields(ulong call, ulong *fields)
get_fields_offset = MAX(MEMBER_OFFSET("ftrace_event_class",
"get_fields"),
MEMBER_OFFSET("trace_event_class", "get_fields"));
if ((sp = symbol_search("syscall_get_enter_fields")) != NULL)
- syscall_get_enter_fields_value = sp->value;
+ syscall_get_enter_fields_value = sp->value & ~1;
if ((sp = symbol_search("syscall_get_exit_fields")) != NULL)
- syscall_get_exit_fields_value = sp->value;
+ syscall_get_exit_fields_value = sp->value & ~1;
work:
if (fields_offset < 0)
@@ -1056,6 +1056,8 @@ work:
return 0;
}
+ get_fields &= ~1;
+
if (get_fields == syscall_get_enter_fields_value)
return syscall_get_enter_fields(call, fields);
---
base-commit: 153629a96b07a8ae96b0b28cce100fde9ea1398d
change-id: 20230612-thumb2-2431fd10df56
Best regards,
--
Vincent Whitchurch <vincent.whitchurch(a)axis.com>