This renaming is present from Linux v5.6 upwards, and was introduced by commit:
1c5eb4481e01 ("tracing: Rename trace_buffer to array_buffer") Rename the internal references from trace_buffer to array_buffer. Backwards compatibility with older kernels is provided by checking whether struct trace_array has an array_buffer field - should that not be the case, the old naming scheme is used instead. Signed-off-by: Valentin Schneider <valentin.schnei...@arm.com> --- extensions/trace.c | 53 ++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 18 deletions(-) diff --git a/extensions/trace.c b/extensions/trace.c index c26b6c7..b4bbb98 100644 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -31,9 +31,9 @@ static int per_cpu_buffer_sizes; */ static int encapsulated_current_trace; /* - * trace_buffer is supported + * array_buffer (trace_buffer pre v5.8) is supported */ -static int trace_buffer_available; +static int array_buffer_available; /* * max_buffer is supported */ @@ -51,9 +51,9 @@ static int buffer_page_real_end_available; #define koffset(struct, member) struct##_##member##_offset static int koffset(trace_array, current_trace); -static int koffset(trace_array, trace_buffer); +static int koffset(trace_array, array_buffer); static int koffset(trace_array, max_buffer); -static int koffset(trace_buffer, buffer); +static int koffset(array_buffer, buffer); static int koffset(trace_array, buffer); static int koffset(tracer, name); @@ -117,7 +117,7 @@ static ulong max_tr_trace; struct trace_instance { char name[NAME_MAX + 1]; - ulong trace_buffer; + ulong array_buffer; ulong max_buffer; ulong ring_buffer; unsigned pages; @@ -174,8 +174,7 @@ static int write_and_check(int fd, void *data, size_t size) static int init_offsets(void) { -#define init_offset(struct, member) do { \ - koffset(struct, member) = MEMBER_OFFSET(#struct, #member);\ +#define check_offset(struct, member) do { \ if (koffset(struct, member) < 0) { \ fprintf(fp, "failed to init the offset, struct:"\ #struct ", member:" #member); \ @@ -184,12 +183,29 @@ static int init_offsets(void) } \ } while (0) +#define init_offset(struct, member) do { \ + koffset(struct, member) = MEMBER_OFFSET(#struct, #member); \ + check_offset(struct, member); \ + } while (0) + +#define init_offset_alternative(struct, member, alt_struct, alt_member) do { \ + koffset(struct, member) = MEMBER_OFFSET(#alt_struct, #alt_member); \ + check_offset(struct, member); \ + } while (0) + if (encapsulated_current_trace) init_offset(trace_array, current_trace); - if (trace_buffer_available) { - init_offset(trace_array, trace_buffer); - init_offset(trace_buffer, buffer); + if (array_buffer_available) { + if (MEMBER_EXISTS("trace_array", "array_buffer")) { + init_offset(trace_array, array_buffer); + init_offset(array_buffer, buffer); + } else { + init_offset_alternative(trace_array, array_buffer, + trace_array, trace_buffer); + init_offset_alternative(array_buffer, buffer, + trace_buffer, buffer); + } if (max_buffer_available) init_offset(trace_array, max_buffer); @@ -486,17 +502,17 @@ out_fail: static int ftrace_init_trace(struct trace_instance *ti, ulong instance_addr) { - if (trace_buffer_available) { - ti->trace_buffer = instance_addr + - koffset(trace_array, trace_buffer); - read_value(ti->ring_buffer, ti->trace_buffer, - trace_buffer, buffer); + if (array_buffer_available) { + ti->array_buffer = instance_addr + + koffset(trace_array, array_buffer); + read_value(ti->ring_buffer, ti->array_buffer, + array_buffer, buffer); if (max_buffer_available) { ti->max_buffer = instance_addr + koffset(trace_array, max_buffer); read_value(ti->max_tr_ring_buffer, ti->max_buffer, - trace_buffer, buffer); + array_buffer, buffer); } } else { read_value(ti->ring_buffer, instance_addr, trace_array, buffer); @@ -683,8 +699,9 @@ static int ftrace_init(void) current_trace = sym_current_trace->value; } - if (MEMBER_EXISTS("trace_array", "trace_buffer")) { - trace_buffer_available = 1; + if (MEMBER_EXISTS("trace_array", "array_buffer") || + MEMBER_EXISTS("trace_array", "trace_buffer")) { + array_buffer_available = 1; if (MEMBER_EXISTS("trace_array", "max_buffer")) max_buffer_available = 1; -- 2.27.0 -- Crash-utility mailing list Crash-utility@redhat.com https://www.redhat.com/mailman/listinfo/crash-utility