diff options
| -rw-r--r-- | include/libcamera/base/backtrace.h | 3 | ||||
| -rw-r--r-- | src/libcamera/base/backtrace.cpp | 67 | ||||
| -rw-r--r-- | src/libcamera/base/meson.build | 6 |
3 files changed, 73 insertions, 3 deletions
diff --git a/include/libcamera/base/backtrace.h b/include/libcamera/base/backtrace.h index aefc76de..58ccc14c 100644 --- a/include/libcamera/base/backtrace.h +++ b/include/libcamera/base/backtrace.h @@ -26,6 +26,9 @@ public: private: LIBCAMERA_DISABLE_COPY(Backtrace) + bool backtraceTrace(); + bool unwindTrace(); + std::vector<void *> backtrace_; }; diff --git a/src/libcamera/base/backtrace.cpp b/src/libcamera/base/backtrace.cpp index 79e4a31f..0aafc6a3 100644 --- a/src/libcamera/base/backtrace.cpp +++ b/src/libcamera/base/backtrace.cpp @@ -18,6 +18,15 @@ #include <unistd.h> #endif +#if HAVE_UNWIND +/* + * Disable support for remote unwinding to enable a more optimized + * implementation. + */ +#define UNW_LOCAL_ONLY +#include <libunwind.h> +#endif + #include <sstream> #include <libcamera/base/span.h> @@ -147,16 +156,65 @@ std::string DwflParser::stackEntry(const void *ip) */ Backtrace::Backtrace() { + /* Try libunwind first and fall back to backtrace() if it fails. */ + if (unwindTrace()) + return; + + backtraceTrace(); +} + +/* + * Avoid inlining to make sure that the Backtrace constructor adds exactly two + * calls to the stack, which are later skipped in toString(). + */ +__attribute__((__noinline__)) +bool Backtrace::backtraceTrace() +{ #if HAVE_BACKTRACE backtrace_.resize(32); int num_entries = backtrace(backtrace_.data(), backtrace_.size()); if (num_entries < 0) { backtrace_.clear(); - return; + return false; } backtrace_.resize(num_entries); + + return true; +#else + return false; +#endif +} + +__attribute__((__noinline__)) +bool Backtrace::unwindTrace() +{ +#if HAVE_UNWIND + unw_context_t uc; + int ret = unw_getcontext(&uc); + if (ret) + return false; + + unw_cursor_t cursor; + ret = unw_init_local(&cursor, &uc); + if (ret) + return false; + + do { + unw_word_t ip; + ret = unw_get_reg(&cursor, UNW_REG_IP, &ip); + if (ret) { + backtrace_.push_back(nullptr); + continue; + } + + backtrace_.push_back(reinterpret_cast<void *>(ip)); + } while (unw_step(&cursor) > 0); + + return true; +#else + return false; #endif } @@ -181,8 +239,11 @@ Backtrace::Backtrace() */ std::string Backtrace::toString(unsigned int skipLevels) const { - /* Skip the first entry, corresponding to the Backtrace construction. */ - skipLevels += 1; + /* + * Skip the first two entries, corresponding to the Backtrace + * construction. + */ + skipLevels += 2; if (backtrace_.size() <= skipLevels) return std::string(); diff --git a/src/libcamera/base/meson.build b/src/libcamera/base/meson.build index 4c44b9f5..05fed7ac 100644 --- a/src/libcamera/base/meson.build +++ b/src/libcamera/base/meson.build @@ -20,6 +20,7 @@ libcamera_base_sources = files([ ]) libdw = cc.find_library('libdw', required : false) +libunwind = cc.find_library('libunwind', required : false) if cc.has_header_symbol('execinfo.h', 'backtrace') config_h.set('HAVE_BACKTRACE', 1) @@ -29,10 +30,15 @@ if libdw.found() config_h.set('HAVE_DW', 1) endif +if libunwind.found() + config_h.set('HAVE_UNWIND', 1) +endif + libcamera_base_deps = [ dependency('threads'), libatomic, libdw, + libunwind, ] # Internal components must use the libcamera_base_private dependency to enable |