More libbacktrace fixes.
Included in minor fix ups is the addition of a warning macro to replace
all of the ALOGW calls.
Fix a race where multiple threads could be attempting to unwind the threads
of the current process at the same time.
Bug: 8410085
Change-Id: I02a65dc778dde690e5f95fc8ff069a32d0832fd1
diff --git a/libbacktrace/UnwindCurrent.cpp b/libbacktrace/UnwindCurrent.cpp
index 0280e93..d4ba68f 100644
--- a/libbacktrace/UnwindCurrent.cpp
+++ b/libbacktrace/UnwindCurrent.cpp
@@ -27,9 +27,9 @@
#include "UnwindCurrent.h"
+// Define the ucontext_t structures needed for each supported arch.
#if defined(__arm__)
- #if !defined(__BIONIC_HAVE_UCONTEXT_T)
- // The Current version of the Android <signal.h> doesn't define ucontext_t.
+ // The current version of the <signal.h> doesn't define ucontext_t.
#include <asm/sigcontext.h> // Ensure 'struct sigcontext' is defined.
// Machine context at the time a signal was raised.
@@ -40,8 +40,19 @@
struct sigcontext uc_mcontext;
uint32_t uc_sigmask;
} ucontext_t;
- #endif // !__BIONIC_HAVE_UCONTEXT_T
-#endif // defined(__arm__)
+#elif defined(__mips__)
+ typedef struct ucontext {
+ uint32_t sp;
+ uint32_t ra;
+ uint32_t pc;
+ } ucontext_t;
+#elif defined(__i386__)
+ #include <asm/sigcontext.h>
+ #include <asm/ucontext.h>
+ typedef struct ucontext ucontext_t;
+#else
+ #error Unsupported architecture.
+#endif
//-------------------------------------------------------------------------
// UnwindCurrent functions.
@@ -55,7 +66,7 @@
bool UnwindCurrent::Unwind(size_t num_ignore_frames) {
int ret = unw_getcontext(&context_);
if (ret < 0) {
- ALOGW("UnwindCurrent::Unwind: unw_getcontext failed %d\n", ret);
+ BACK_LOGW("unw_getcontext failed %d", ret);
return false;
}
return UnwindFromContext(num_ignore_frames, true);
@@ -81,7 +92,7 @@
unw_cursor_t* cursor = new unw_cursor_t;
int ret = unw_init_local(cursor, &context_);
if (ret < 0) {
- ALOGW("UnwindCurrent::UnwindWithContext: unw_init_local failed %d\n", ret);
+ BACK_LOGW("unw_init_local failed %d", ret);
return false;
}
@@ -89,13 +100,13 @@
unw_word_t pc;
ret = unw_get_reg(cursor, UNW_REG_IP, &pc);
if (ret < 0) {
- ALOGW("UnwindCurrent::UnwindWithContext: Failed to read IP %d\n", ret);
+ BACK_LOGW("Failed to read IP %d", ret);
break;
}
unw_word_t sp;
ret = unw_get_reg(cursor, UNW_REG_SP, &sp);
if (ret < 0) {
- ALOGW("UnwindCurrent::UnwindWithContext: Failed to read SP %d\n", ret);
+ BACK_LOGW("Failed to read SP %d", ret);
break;
}
@@ -142,10 +153,9 @@
void UnwindCurrent::ExtractContext(void* sigcontext) {
unw_tdep_context_t* context = reinterpret_cast<unw_tdep_context_t*>(&context_);
-
-#if defined(__arm__)
const ucontext_t* uc = reinterpret_cast<const ucontext_t*>(sigcontext);
+#if defined(__arm__)
context->regs[0] = uc->uc_mcontext.arm_r0;
context->regs[1] = uc->uc_mcontext.arm_r1;
context->regs[2] = uc->uc_mcontext.arm_r2;
@@ -162,28 +172,11 @@
context->regs[13] = uc->uc_mcontext.arm_sp;
context->regs[14] = uc->uc_mcontext.arm_lr;
context->regs[15] = uc->uc_mcontext.arm_pc;
-
#elif defined(__mips__)
-
- typedef struct ucontext {
- uint32_t sp;
- uint32_t ra;
- uint32_t pc;
- } ucontext_t;
-
- const ucontext_t* uc = (const ucontext_t*)sigcontext;
-
context->uc_mcontext.sp = uc->sp;
context->uc_mcontext.pc = uc->pc;
context->uc_mcontext.ra = uc->ra;
-#elif defined(__x86__)
-
- #include <asm/sigcontext.h>
- #include <asm/ucontext.h>
- typedef struct ucontext ucontext_t;
-
- const ucontext_t* uc = (const ucontext_t*)sigcontext;
-
+#elif defined(__i386__)
context->uc_mcontext.gregs[REG_EBP] = uc->uc_mcontext.gregs[REG_EBP];
context->uc_mcontext.gregs[REG_ESP] = uc->uc_mcontext.gregs[REG_ESP];
context->uc_mcontext.gregs[REG_EIP] = uc->uc_mcontext.gregs[REG_EIP];