From e62fae9d9e85d38cdda1ee08a424e1b5b8246620 Mon Sep 17 00:00:00 2001 From: Shimin Guo Date: Fri, 16 Jan 2026 21:28:30 -0800 Subject: [PATCH] perf unwind-libdw: Fix a cross-arch unwinding bug MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The set_initial_registers field of Dwfl_Thread_Callbacks needs to be set according to the arch of the stack samples being analyzed, not the arch that perf itself is built for. Currently perf fails to unwind stack samples collected from archs different from that of the host perf is running on. This patch moves the arch-specific implementations of set_initial_registers from tools/perf/arch to tools/perf/utli/unwind-libdw-arch, similar to the way the perf-regs-arch folder contains arch-specific functions related to registers, and chooses the implementation based on the arch of the data being processed. Reviewed-by: Ian Rogers Signed-off-by: Shimin Guo Acked-by: Namhyung Kim Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Chun-Tse Shao Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Guo Ren Cc: Haibo Xu Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Krzysztof Łopatowski Cc: Leo Yan Cc: Mark Wielaard Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Stephen Brennan Cc: Thomas Falcon Cc: Will Deacon Signed-off-by: Ian Rogers Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/arm/util/Build | 1 - tools/perf/arch/arm64/util/Build | 1 - tools/perf/arch/csky/util/Build | 2 - tools/perf/arch/powerpc/util/Build | 1 - tools/perf/arch/riscv/util/Build | 1 - tools/perf/arch/s390/util/Build | 2 - tools/perf/arch/x86/util/Build | 1 - tools/perf/util/Build | 1 + tools/perf/util/unwind-libdw-arch/Build | 8 +++ .../unwind-libdw-arch/unwind-libdw-arm.c} | 10 ++-- .../unwind-libdw-arch/unwind-libdw-arm64.c} | 10 ++-- .../unwind-libdw-arch/unwind-libdw-csky.c} | 10 ++-- .../unwind-libdw-loongarch.c} | 10 ++-- .../unwind-libdw-arch/unwind-libdw-powerpc.c} | 10 ++-- .../unwind-libdw-arch/unwind-libdw-riscv.c} | 10 ++-- .../unwind-libdw-arch/unwind-libdw-s390.c} | 14 ++--- .../unwind-libdw-arch/unwind-libdw-x86.c} | 8 +-- tools/perf/util/unwind-libdw.c | 51 ++++++++++++++++--- tools/perf/util/unwind-libdw.h | 10 +++- 19 files changed, 104 insertions(+), 57 deletions(-) create mode 100644 tools/perf/util/unwind-libdw-arch/Build rename tools/perf/{arch/arm/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-arm.c} (80%) rename tools/perf/{arch/arm64/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-arm64.c} (87%) rename tools/perf/{arch/csky/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-csky.c} (90%) rename tools/perf/{arch/loongarch/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-loongarch.c} (86%) rename tools/perf/{arch/powerpc/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-powerpc.c} (89%) rename tools/perf/{arch/riscv/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-riscv.c} (87%) rename tools/perf/{arch/s390/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-s390.c} (84%) rename tools/perf/{arch/x86/util/unwind-libdw.c => util/unwind-libdw-arch/unwind-libdw-x86.c} (87%) diff --git a/tools/perf/arch/arm/util/Build b/tools/perf/arch/arm/util/Build index fd695e1fdaee2..3291f893b943d 100644 --- a/tools/perf/arch/arm/util/Build +++ b/tools/perf/arch/arm/util/Build @@ -1,6 +1,5 @@ perf-util-y += perf_regs.o perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o perf-util-y += pmu.o auxtrace.o cs-etm.o diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build index d63881081d2eb..0177af19cc000 100644 --- a/tools/perf/arch/arm64/util/Build +++ b/tools/perf/arch/arm64/util/Build @@ -1,4 +1,3 @@ -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o perf-util-y += ../../arm/util/auxtrace.o diff --git a/tools/perf/arch/csky/util/Build b/tools/perf/arch/csky/util/Build index 5e6ea82c42021..6b2d0e021b114 100644 --- a/tools/perf/arch/csky/util/Build +++ b/tools/perf/arch/csky/util/Build @@ -1,3 +1 @@ perf-util-y += perf_regs.o - -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o diff --git a/tools/perf/arch/powerpc/util/Build b/tools/perf/arch/powerpc/util/Build index 3d0d5427aef7f..5fd28ec713a4d 100644 --- a/tools/perf/arch/powerpc/util/Build +++ b/tools/perf/arch/powerpc/util/Build @@ -9,5 +9,4 @@ perf-util-y += evsel.o perf-util-$(CONFIG_LIBDW) += skip-callchain-idx.o perf-util-$(CONFIG_LIBUNWIND) += unwind-libunwind.o -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o perf-util-y += auxtrace.o diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build index 58a672246024d..628b9ebd418bd 100644 --- a/tools/perf/arch/riscv/util/Build +++ b/tools/perf/arch/riscv/util/Build @@ -2,4 +2,3 @@ perf-util-y += perf_regs.o perf-util-y += header.o perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build index c64eb18dbdae9..5391d26fedd46 100644 --- a/tools/perf/arch/s390/util/Build +++ b/tools/perf/arch/s390/util/Build @@ -2,8 +2,6 @@ perf-util-y += header.o perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o perf-util-y += perf_regs.o -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o - perf-util-y += machine.o perf-util-y += pmu.o diff --git a/tools/perf/arch/x86/util/Build b/tools/perf/arch/x86/util/Build index c0dc5965f3624..fad256252bb95 100644 --- a/tools/perf/arch/x86/util/Build +++ b/tools/perf/arch/x86/util/Build @@ -12,7 +12,6 @@ perf-util-y += evsel.o perf-util-y += iostat.o perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o -perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o perf-util-y += auxtrace.o perf-util-y += archinsn.o diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 4915f237ba9e3..5efec73be4743 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -227,6 +227,7 @@ perf-util-$(CONFIG_LIBDW) += annotate-data.o perf-util-$(CONFIG_LIBDW) += libdw.o perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o +perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw-arch/ perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind-local.o perf-util-$(CONFIG_LIBUNWIND) += unwind-libunwind.o perf-util-$(CONFIG_LIBUNWIND_X86) += libunwind/x86_32.o diff --git a/tools/perf/util/unwind-libdw-arch/Build b/tools/perf/util/unwind-libdw-arch/Build new file mode 100644 index 0000000000000..ef17a83a78136 --- /dev/null +++ b/tools/perf/util/unwind-libdw-arch/Build @@ -0,0 +1,8 @@ +perf-util-y += unwind-libdw-x86.o +perf-util-y += unwind-libdw-arm.o +perf-util-y += unwind-libdw-arm64.o +perf-util-y += unwind-libdw-csky.o +perf-util-y += unwind-libdw-loongarch.o +perf-util-y += unwind-libdw-powerpc.o +perf-util-y += unwind-libdw-riscv.o +perf-util-y += unwind-libdw-s390.o diff --git a/tools/perf/arch/arm/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-arm.c similarity index 80% rename from tools/perf/arch/arm/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-arm.c index fbb643f224ec4..56e9b5975bcc6 100644 --- a/tools/perf/arch/arm/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-arm.c @@ -1,11 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include "perf_regs.h" -#include "../../../util/unwind-libdw.h" -#include "../../../util/perf_regs.h" -#include "../../../util/sample.h" +#include "../arch/arm/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_arm(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/arm64/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-arm64.c similarity index 87% rename from tools/perf/arch/arm64/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-arm64.c index b89b0a7e5ad91..29b6833e036cc 100644 --- a/tools/perf/arch/arm64/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-arm64.c @@ -1,11 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include "perf_regs.h" -#include "../../../util/unwind-libdw.h" -#include "../../../util/perf_regs.h" -#include "../../../util/sample.h" +#include "../arch/arm64/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_arm64(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/csky/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c similarity index 90% rename from tools/perf/arch/csky/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c index b20b1569783d7..2556d034c32a4 100644 --- a/tools/perf/arch/csky/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c @@ -2,12 +2,12 @@ // Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd. #include -#include "perf_regs.h" -#include "../../util/unwind-libdw.h" -#include "../../util/perf_regs.h" -#include "../../util/event.h" +#include "../arch/csky/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_csky(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/loongarch/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-loongarch.c similarity index 86% rename from tools/perf/arch/loongarch/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-loongarch.c index 60b1144bedd5f..5fca673508be8 100644 --- a/tools/perf/arch/loongarch/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-loongarch.c @@ -2,12 +2,12 @@ /* Copyright (C) 2020-2023 Loongson Technology Corporation Limited */ #include -#include "perf_regs.h" -#include "../../util/unwind-libdw.h" -#include "../../util/perf_regs.h" -#include "../../util/sample.h" +#include "../arch/loongarch/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_loongarch(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/powerpc/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-powerpc.c similarity index 89% rename from tools/perf/arch/powerpc/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-powerpc.c index 82d0c28ae3459..1560db45e7b46 100644 --- a/tools/perf/arch/powerpc/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-powerpc.c @@ -1,10 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 #include #include -#include "perf_regs.h" -#include "../../../util/unwind-libdw.h" -#include "../../../util/perf_regs.h" -#include "../../../util/sample.h" +#include "../arch/powerpc/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" /* See backends/ppc_initreg.c and backends/ppc_regs.c in elfutils. */ static const int special_regs[3][2] = { @@ -13,7 +13,7 @@ static const int special_regs[3][2] = { { 109, PERF_REG_POWERPC_CTR }, }; -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_powerpc(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/riscv/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-riscv.c similarity index 87% rename from tools/perf/arch/riscv/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-riscv.c index dc1476e163217..c2e2c4b6b2e00 100644 --- a/tools/perf/arch/riscv/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-riscv.c @@ -2,12 +2,12 @@ /* Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd. */ #include -#include "perf_regs.h" -#include "../../util/unwind-libdw.h" -#include "../../util/perf_regs.h" -#include "../../util/sample.h" +#include "../arch/riscv/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_riscv(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/s390/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-s390.c similarity index 84% rename from tools/perf/arch/s390/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-s390.c index c27c7a0d1076c..1e05e9d9d95fa 100644 --- a/tools/perf/arch/s390/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-s390.c @@ -1,14 +1,14 @@ #include #include -#include "../../util/unwind-libdw.h" -#include "../../util/perf_regs.h" -#include "../../util/event.h" -#include "../../util/sample.h" -#include "dwarf-regs-table.h" -#include "perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" +#include "util/event.h" +#include "util/sample.h" +#include "../arch/s390/include/dwarf-regs-table.h" +#include "../arch/s390/include/uapi/asm/perf_regs.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_s390(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/arch/x86/util/unwind-libdw.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-x86.c similarity index 87% rename from tools/perf/arch/x86/util/unwind-libdw.c rename to tools/perf/util/unwind-libdw-arch/unwind-libdw-x86.c index 798493e887d73..dd27545a4a68c 100644 --- a/tools/perf/arch/x86/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw-arch/unwind-libdw-x86.c @@ -1,11 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 #include -#include "perf_regs.h" -#include "../../../util/unwind-libdw.h" -#include "../../../util/perf_regs.h" +#include "../arch/x86/include/uapi/asm/perf_regs.h" +#include "util/unwind-libdw.h" +#include "util/perf_regs.h" #include "util/sample.h" -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg) +bool libdw_set_initial_registers_x86(Dwfl_Thread *thread, void *arg) { struct unwind_info *ui = arg; struct regs_dump *user_regs = perf_sample__user_regs(ui->sample); diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c index 3ff427a49e4c5..b2e194a8be396 100644 --- a/tools/perf/util/unwind-libdw.c +++ b/tools/perf/util/unwind-libdw.c @@ -225,11 +225,45 @@ static bool memory_read(Dwfl *dwfl __maybe_unused, Dwarf_Addr addr, Dwarf_Word * return true; } -static const Dwfl_Thread_Callbacks callbacks = { - .next_thread = next_thread, - .memory_read = memory_read, - .set_initial_registers = libdw__arch_set_initial_registers, -}; +#define DEFINE_DWFL_THREAD_CALLBACKS(arch) \ +static const Dwfl_Thread_Callbacks callbacks_##arch = { \ + .next_thread = next_thread, \ + .memory_read = memory_read, \ + .set_initial_registers = libdw_set_initial_registers_##arch, \ +} + +DEFINE_DWFL_THREAD_CALLBACKS(x86); +DEFINE_DWFL_THREAD_CALLBACKS(arm); +DEFINE_DWFL_THREAD_CALLBACKS(arm64); +DEFINE_DWFL_THREAD_CALLBACKS(csky); +DEFINE_DWFL_THREAD_CALLBACKS(loongarch); +DEFINE_DWFL_THREAD_CALLBACKS(powerpc); +DEFINE_DWFL_THREAD_CALLBACKS(riscv); +DEFINE_DWFL_THREAD_CALLBACKS(s390); + +static const Dwfl_Thread_Callbacks *get_thread_callbacks(const char *arch) +{ + if (!strcmp(arch, "arm")) + return &callbacks_arm; + else if (!strcmp(arch, "arm64")) + return &callbacks_arm64; + else if (!strcmp(arch, "csky")) + return &callbacks_csky; + else if (!strcmp(arch, "loongarch")) + return &callbacks_loongarch; + else if (!strcmp(arch, "powerpc")) + return &callbacks_powerpc; + else if (!strcmp(arch, "riscv")) + return &callbacks_riscv; + else if (!strcmp(arch, "s390")) + return &callbacks_s390; + else if (!strcmp(arch, "x86")) + return &callbacks_x86; + + pr_err("Fail to get thread callbacks for arch %s, returns NULL\n", + arch); + return NULL; +} static int frame_callback(Dwfl_Frame *state, void *arg) @@ -278,6 +312,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, const char *arch = perf_env__arch(ui_buf.machine->env); Dwarf_Word ip; int err = -EINVAL, i; + const Dwfl_Thread_Callbacks *callbacks; if (!data->user_regs || !data->user_regs->regs) return -EINVAL; @@ -300,7 +335,11 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg, if (err) goto out; - err = !dwfl_attach_state(ui->dwfl, EM_NONE, thread__tid(thread), &callbacks, ui); + callbacks = get_thread_callbacks(arch); + if (!callbacks) + goto out; + + err = !dwfl_attach_state(ui->dwfl, EM_NONE, thread__tid(thread), callbacks, ui); if (err) goto out; diff --git a/tools/perf/util/unwind-libdw.h b/tools/perf/util/unwind-libdw.h index 8c88bc4f2304b..574b29848cce3 100644 --- a/tools/perf/util/unwind-libdw.h +++ b/tools/perf/util/unwind-libdw.h @@ -9,7 +9,15 @@ struct machine; struct perf_sample; struct thread; -bool libdw__arch_set_initial_registers(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_x86(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_arm(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_arm64(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_csky(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_loongarch(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_mips(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_powerpc(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_riscv(Dwfl_Thread *thread, void *arg); +bool libdw_set_initial_registers_s390(Dwfl_Thread *thread, void *arg); struct unwind_info { Dwfl *dwfl; -- 2.47.3