[PATCH] libubacktrace: Add arm implementation
Carmelo AMOROSO
carmelo.amoroso at st.com
Sat Jan 21 14:47:10 UTC 2012
On 21/01/2012 15.08, Khem Raj wrote:
> Arm has a different mechanism of getting
> _Unwind_GetIP. Therefore we profile arch
> specific backtrace file.
>
> Signed-off-by: Khem Raj <raj.khem at gmail.com>
> ---
> libubacktrace/Makefile.in | 26 ++++++++--
> libubacktrace/arm/Makefile.arch | 21 ++++++++
> libubacktrace/arm/backtrace.c | 104 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 145 insertions(+), 6 deletions(-)
> create mode 100644 libubacktrace/arm/Makefile.arch
> create mode 100644 libubacktrace/arm/backtrace.c
>
> diff --git a/libubacktrace/Makefile.in b/libubacktrace/Makefile.in
> index b18e3e6..f675bf5 100644
> --- a/libubacktrace/Makefile.in
> +++ b/libubacktrace/Makefile.in
> @@ -6,7 +6,7 @@
> # Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
> #
>
> -subdirs += libubacktrace
> +subdirs += libubacktrace libubacktrace/$(TARGET_ARCH)
>
> CFLAGS-libubacktrace := -DNOT_IN_libc -DIS_IN_libubacktrace $(SSP_ALL_CFLAGS)
>
> @@ -23,22 +23,36 @@ libubacktrace_FULL_NAME := libubacktrace-$(VERSION).so
> libubacktrace_DIR := $(top_srcdir)libubacktrace
> libubacktrace_OUT := $(top_builddir)libubacktrace
>
> +libubacktrace_ARCH_DIR:=$(libubacktrace_DIR)/$(TARGET_ARCH)
> +libubacktrace_ARCH_OUT:=$(libubacktrace_OUT)/$(TARGET_ARCH)
> +
> +-include $(libubacktrace_ARCH_DIR)/Makefile.arch
> +
> libubacktrace_SRC-y :=
> libubacktrace_SRC-$(UCLIBC_HAS_BACKTRACE) := backtrace.c backtracesyms.c backtracesymsfd.c
>
> +# remove generic sources, if arch specific version is present
> +ifneq ($(strip $(libubacktrace_ARCH_SRC-y)),)
> +libubacktrace_SRC-y := $(filter-out $(notdir $(libubacktrace_ARCH_SRC-y)),$(libubacktrace_SRC-y))
> +endif
> +
> # -fasynchronous-unwind-tables is required for backtrace to work using dwarf2
> CFLAGS-backtrace.c := -fasynchronous-unwind-tables
>
> +# pass common flags to arch dirs
> +ifneq ($(strip $(libubacktrace_ARCH_OBJS)),)
> +CFLAGS-libubacktrace/$(TARGET_ARCH)/ := $(CFLAGS-libubacktrace)
> +endif
>
> -libubacktrace_SRCS := $(addprefix $(libubacktrace_DIR)/,$(libubacktrace_SRC-y))
> +libubacktrace_SRCS := $(patsubst %.c,$(libubacktrace_DIR)/%.c,$(libubacktrace_SRC-y))
> libubacktrace_OBJS := $(patsubst $(libubacktrace_DIR)/%.c,$(libubacktrace_OUT)/%.o,$(libubacktrace_SRCS))
>
> ifeq ($(DOPIC),y)
> -libubacktrace-a-y := $(libubacktrace_OBJS:.o=.os)
> +libubacktrace-a-y += $(libubacktrace_OBJS:.o=.os)
> else
> -libubacktrace-a-y := $(libubacktrace_OBJS)
> +libubacktrace-a-y += $(libubacktrace_OBJS)
> endif
> -libubacktrace-so-y := $(libubacktrace_OBJS:.o=.os)
> +libubacktrace-so-y += $(libubacktrace_OBJS:.o=.os)
>
> lib-a-$(UCLIBC_HAS_BACKTRACE) += $(top_builddir)lib/libubacktrace.a
> lib-so-$(UCLIBC_HAS_BACKTRACE) += $(top_builddir)lib/libubacktrace.so
> @@ -61,7 +75,7 @@ $(libubacktrace_OUT)/libubacktrace_so.a: $(libubacktrace-so-y)
> $(Q)$(RM) $@
> $(do_ar)
>
> -$(libubacktrace_OUT)/libubacktrace.oS: $(libubacktrace_SRCS)
> +$(libubacktrace_OUT)/libubacktrace.oS: $(libubacktrace_SRCS) $(libubacktrace_ARCH_SRCS)
> $(Q)$(RM) $@
> $(compile-m)
>
> diff --git a/libubacktrace/arm/Makefile.arch b/libubacktrace/arm/Makefile.arch
> new file mode 100644
> index 0000000..dab3637
> --- /dev/null
> +++ b/libubacktrace/arm/Makefile.arch
> @@ -0,0 +1,21 @@
> +# Makefile for uClibc (libubacktrace)
> +#
> +# Author: Khem Raj <raj.khem at gmail.com>
> +
> +# Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
> +#
> +
> +libubacktrace_ARCH_SRC-$(UCLIBC_HAS_BACKTRACE) := backtrace.c
> +libubacktrace_ARCH_SRCS := $(addprefix $(libubacktrace_ARCH_DIR)/,$(libubacktrace_ARCH_SRC-y))
> +libubacktrace_ARCH_OBJS := $(patsubst $(libubacktrace_ARCH_DIR)/%.c,$(libubacktrace_ARCH_OUT)/%.o,$(libubacktrace_ARCH_SRCS))
> +
> +ifeq ($(DOPIC),y)
> +libubacktrace-a-y+=$(libubacktrace_ARCH_OBJS:.o=.os)
> +else
> +libubacktrace-a-y+=$(libubacktrace_ARCH_OBJS)
> +endif
> +libubacktrace-so-y+=$(libubacktrace_ARCH_OBJS:.o=.os)
> +
> +ifeq ($(CONFIG_ARM_EABI),y)
> +LIBGCC += $(shell $(CC) -print-file-name=libgcc_eh.a)
> +endif
with my proposed patch to move __aeabi_unwind_cpp_pr in uclibc_shared.a
should not be needed.
> diff --git a/libubacktrace/arm/backtrace.c b/libubacktrace/arm/backtrace.c
> new file mode 100644
> index 0000000..8a18c6c
> --- /dev/null
> +++ b/libubacktrace/arm/backtrace.c
> @@ -0,0 +1,104 @@
> +/*
> + * Perform stack unwinding by using the _Unwind_Backtrace.
> + *
> + * User application that wants to use backtrace needs to be
> + * compiled with -fexceptions option and -rdynamic to get full
> + * symbols printed.
> + *
> + * Copyright (C) 2009, 2010 STMicroelectronics Ltd.
> + *
> + * Author(s): Giuseppe Cavallaro <peppe.cavallaro at st.com>
> + * - Initial implementation for glibc
> + *
> + * Author(s): Carmelo Amoroso <carmelo.amoroso at st.com>
> + * - Reworked for uClibc
> + * - use dlsym/dlopen from libdl
> + * - rewrite initialisation to not use libc_once
> + * - make it available in static link too
> + *
fell free to remove old authorship
> + * Author(s): Khem Raj <raj.khem at gmail.com>
> + * - Add arm specific implementation
> + *
> + * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
> + *
> + */
> +
> +#include <execinfo.h>
> +#include <dlfcn.h>
> +#include <stdlib.h>
> +#include <unwind.h>
> +#include <assert.h>
> +#include <stdio.h>
> +
> +struct trace_arg
> +{
> + void **array;
> + int cnt, size;
> +};
> +
> +static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
> +static _Unwind_VRS_Result (*unwind_vrs_get) (_Unwind_Context *,
> + _Unwind_VRS_RegClass,
> + _uw,
> + _Unwind_VRS_DataRepresentation,
> + void *);
> +
> +static void backtrace_init (void)
> +{
> + void *handle = dlopen ("libgcc_s.so.1", RTLD_LAZY);
> + if (handle == NULL
> + || ((unwind_backtrace = dlsym (handle, "_Unwind_Backtrace")) == NULL)
> + || ((unwind_vrs_get = dlsym (handle, "_Unwind_VRS_Get")) == NULL)) {
> + printf("libgcc_s.so.1 must be installed for backtrace to work\n");
> + abort();
> + }
> +}
> +/* This function is identical to "_Unwind_GetGR", except that it uses
> + "unwind_vrs_get" instead of "_Unwind_VRS_Get". */
> +static inline _Unwind_Word
> +unwind_getgr (_Unwind_Context *context, int regno)
> +{
> + _uw val;
> + unwind_vrs_get (context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val);
> + return val;
> +}
> +
> +/* This macro is identical to the _Unwind_GetIP macro, except that it
> + uses "unwind_getgr" instead of "_Unwind_GetGR". */
> +#define unwind_getip(context) \
> + (unwind_getgr (context, 15) & ~(_Unwind_Word)1)
> +
> +static _Unwind_Reason_Code
> +backtrace_helper (struct _Unwind_Context *ctx, void *a)
> +{
> + struct trace_arg *arg = a;
> +
> + assert (unwind_getip != NULL);
> +
> + /* We are first called with address in the __backtrace function. Skip it. */
> + if (arg->cnt != -1)
> + arg->array[arg->cnt] = (void *) unwind_getip (ctx);
> + if (++arg->cnt == arg->size)
> + return _URC_END_OF_STACK;
> + return _URC_NO_REASON;
> +}
> +
> +/*
> + * Perform stack unwinding by using the _Unwind_Backtrace.
> + *
> + * User application that wants to use backtrace needs to be
> + * compiled with -fexceptions option and -rdynamic to get full
-fasynchronous-unwid-tables shold be referenced, instead of -fexecptions
> + * symbols printed.
> + */
> +int backtrace (void **array, int size)
> +{
> + struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
> +
> + if (unwind_backtrace == NULL)
> + backtrace_init();
> +
> + if (size >= 1)
> + unwind_backtrace (backtrace_helper, &arg);
> +
> + return arg.cnt != -1 ? arg.cnt : 0;
> +}
Cheers,
Carmelo
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