Change the sample_set_initial_registers callback in eu-stacktrace to
use the proper libebl ebl_set_initial_registers_sample function.
* src/Makefile.am (stacktrace_LDADD): Add libebl.
* src/stacktrace.c (sample_registers_cb): New function,
though identical to pid_thread_state_registers_cb.
(sample_set_initial_registers): Invoke
ebl_set_initial_registers_sample instead of containing
platform-specific code directly.
---
src/Makefile.am | 4 ++--
src/stacktrace.c | 48 +++++++++++++-----------------------------------
2 files changed, 15 insertions(+), 37 deletions(-)
diff --git a/src/Makefile.am b/src/Makefile.am
index ed245fc1..6d713e88 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,6 +1,6 @@
## Process this file with automake to create Makefile.in
##
-## Copyright (C) 1996-2014, 2016, 2024 Red Hat, Inc.
+## Copyright (C) 1996-2014, 2016, 2024-2025 Red Hat, Inc.
## This file is part of elfutils.
##
## This file is free software; you can redistribute it and/or modify
@@ -105,7 +105,7 @@ ar_LDADD = libar.a $(libelf) $(libeu) $(argp_LDADD)
$(obstack_LIBS)
unstrip_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD)
stack_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD)
$(demanglelib)
if ENABLE_STACKTRACE
-stacktrace_LDADD = $(libelf) $(libdw) $(libeu) $(argp_LDADD)
+stacktrace_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD)
endif
elfcompress_LDADD = $(libebl) $(libelf) $(libdw) $(libeu) $(argp_LDADD)
elfclassify_LDADD = $(libelf) $(libdw) $(libeu) $(argp_LDADD)
diff --git a/src/stacktrace.c b/src/stacktrace.c
index d8699ce5..7b498e40 100644
--- a/src/stacktrace.c
+++ b/src/stacktrace.c
@@ -1,5 +1,5 @@
/* Process a stream of stack samples into stack traces.
- Copyright (C) 2023-2024 Red Hat, Inc.
+ Copyright (C) 2023-2025 Red Hat, Inc.
This file is part of elfutils.
This file is free software; you can redistribute it and/or modify
@@ -93,9 +93,11 @@
* Includes: libdwfl data structures *
*************************************/
+#include ELFUTILS_HEADER(ebl)
/* #include ELFUTILS_HEADER(dwfl) */
#include "../libdwfl/libdwflP.h"
-/* XXX: Private header needed for find_procfile, sysprof_init_dwfl */
+/* XXX: Private header needed for find_procfile, sysprof_init_dwfl,
+ sample_set_initial_registers. */
/*************************************
* Includes: sysprof data structures *
@@ -574,42 +576,18 @@ sample_memory_read (Dwfl *dwfl, Dwarf_Addr addr,
Dwarf_Word *result, void *arg)
return true;
}
-/* TODO: Need to generalize this code beyond x86 architectures. */
static bool
-sample_set_initial_registers (Dwfl_Thread *thread, void *thread_arg)
+sample_set_initial_registers (Dwfl_Thread *thread, void *arg)
{
- /* The following facts are needed to translate x86 registers correctly:
- - perf register order seen in linux arch/x86/include/uapi/asm/perf_regs.h
- The registers array is built in the same order as the enum!
- (See the code in tools/perf/util/intel-pt.c intel_pt_add_gp_regs().)
- - sysprof libsysprof/perf-event-stream-private.h records all registers
- except segment and flags.
- - TODO: Should include the perf regs mask in sysprof data and
- translate registers in fully-general fashion, removing this
assumption.
- - dwarf register order seen in elfutils backends/{x86_64,i386}_initreg.c;
- and it's a fairly different register order!
-
- For comparison, you can study
codereview.qt-project.org/gitweb?p=qt-creator/perfparser.git;a=blob;f=app/perfregisterinfo.cpp;hb=HEAD
- and follow the code which uses those tables of magic numbers.
- But it's better to follow original sources of truth for this. */
- struct __sample_arg *sample_arg = (struct __sample_arg *)thread_arg;
- bool is_abi32 = (sample_arg->abi == PERF_SAMPLE_REGS_ABI_32);
- static const int regs_i386[] = {0, 2, 3, 1, 7/*sp*/, 6, 4, 5, 8/*ip*/};
- static const int regs_x86_64[] = {0, 3, 2, 1, 4, 5, 6, 7/*sp*/, 9, 10, 11,
12, 13, 14, 15, 16, 8/*ip*/};
- const int *reg_xlat = is_abi32 ? regs_i386 : regs_x86_64;
- int n_regs = is_abi32 ? 9 : 17;
+ struct __sample_arg *sample_arg = (struct __sample_arg *)arg;
dwfl_thread_state_register_pc (thread, sample_arg->pc);
- if (sample_arg->n_regs < (uint64_t)n_regs && show_failures)
- fprintf(stderr, N_("sample_set_initial_regs: n_regs=%ld, expected %d\n"),
- sample_arg->n_regs, n_regs);
- for (int i = 0; i < n_regs; i++)
- {
- int j = reg_xlat[i];
- if (j < 0) continue;
- if (sample_arg->n_regs <= (uint64_t)j) continue;
- dwfl_thread_state_registers (thread, i, 1, &sample_arg->regs[j]);
- }
- return true;
+ Dwfl_Process *process = thread->process;
+ Ebl *ebl = process->ebl;
+ /* XXX Sysprof provides exactly the required registers for unwinding: */
+ uint64_t regs_mask = ebl_perf_frame_regs_mask (ebl);
+ return ebl_set_initial_registers_sample
+ (ebl, sample_arg->regs, sample_arg->n_regs, regs_mask, sample_arg->abi,
+ dwfl_set_initial_registers_thread, thread);
}
static void
--
2.47.0
