[PATCH] libubacktrace: Add arm implementation
Khem Raj
raj.khem at gmail.com
Sat Jan 21 19:42:06 UTC 2012
On Sat, Jan 21, 2012 at 6:47 AM, Carmelo AMOROSO <carmelo.amoroso at st.com> wrote:
> 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.
lets make this change after you have installed that patch. For now I will
keep it.
>
>> 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
ok
>
>> + * 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
right. changed locally.
>
>> + * 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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