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path: root/src/pal/src/exception/seh-unwind.cpp
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Diffstat (limited to 'src/pal/src/exception/seh-unwind.cpp')
-rw-r--r--src/pal/src/exception/seh-unwind.cpp76
1 files changed, 58 insertions, 18 deletions
diff --git a/src/pal/src/exception/seh-unwind.cpp b/src/pal/src/exception/seh-unwind.cpp
index 24eebbbf94..fa2f109875 100644
--- a/src/pal/src/exception/seh-unwind.cpp
+++ b/src/pal/src/exception/seh-unwind.cpp
@@ -73,6 +73,14 @@ Abstract:
ASSIGN_REG(X26) \
ASSIGN_REG(X27) \
ASSIGN_REG(X28)
+#elif defined(_X86_)
+#define ASSIGN_UNWIND_REGS \
+ ASSIGN_REG(Eip) \
+ ASSIGN_REG(Esp) \
+ ASSIGN_REG(Ebp) \
+ ASSIGN_REG(Ebx) \
+ ASSIGN_REG(Esi) \
+ ASSIGN_REG(Edi)
#else
#error unsupported architecture
#endif
@@ -122,6 +130,13 @@ static void WinContextToUnwindCursor(CONTEXT *winContext, unw_cursor_t *cursor)
unw_set_reg(cursor, UNW_X86_64_R13, winContext->R13);
unw_set_reg(cursor, UNW_X86_64_R14, winContext->R14);
unw_set_reg(cursor, UNW_X86_64_R15, winContext->R15);
+#elif defined(_X86_)
+ unw_set_reg(cursor, UNW_REG_IP, winContext->Eip);
+ unw_set_reg(cursor, UNW_REG_SP, winContext->Esp);
+ unw_set_reg(cursor, UNW_X86_EBP, winContext->Ebp);
+ unw_set_reg(cursor, UNW_X86_EBX, winContext->Ebx);
+ unw_set_reg(cursor, UNW_X86_ESI, winContext->Esi);
+ unw_set_reg(cursor, UNW_X86_EDI, winContext->Edi);
#endif
}
#endif
@@ -137,6 +152,13 @@ static void UnwindContextToWinContext(unw_cursor_t *cursor, CONTEXT *winContext)
unw_get_reg(cursor, UNW_X86_64_R13, (unw_word_t *) &winContext->R13);
unw_get_reg(cursor, UNW_X86_64_R14, (unw_word_t *) &winContext->R14);
unw_get_reg(cursor, UNW_X86_64_R15, (unw_word_t *) &winContext->R15);
+#elif defined(_X86_)
+ unw_get_reg(cursor, UNW_REG_IP, (unw_word_t *) &winContext->Eip);
+ unw_get_reg(cursor, UNW_REG_SP, (unw_word_t *) &winContext->Esp);
+ unw_get_reg(cursor, UNW_X86_EBP, (unw_word_t *) &winContext->Ebp);
+ unw_get_reg(cursor, UNW_X86_EBX, (unw_word_t *) &winContext->Ebx);
+ unw_get_reg(cursor, UNW_X86_ESI, (unw_word_t *) &winContext->Esi);
+ unw_get_reg(cursor, UNW_X86_EDI, (unw_word_t *) &winContext->Edi);
#elif defined(_ARM_)
unw_get_reg(cursor, UNW_REG_SP, (unw_word_t *) &winContext->Sp);
unw_get_reg(cursor, UNW_REG_IP, (unw_word_t *) &winContext->Pc);
@@ -196,6 +218,11 @@ static void GetContextPointers(unw_cursor_t *cursor, unw_context_t *unwContext,
GetContextPointer(cursor, unwContext, UNW_X86_64_R13, &contextPointers->R13);
GetContextPointer(cursor, unwContext, UNW_X86_64_R14, &contextPointers->R14);
GetContextPointer(cursor, unwContext, UNW_X86_64_R15, &contextPointers->R15);
+#elif defined(_X86_)
+ GetContextPointer(cursor, unwContext, UNW_X86_EBX, &contextPointers->Ebx);
+ GetContextPointer(cursor, unwContext, UNW_X86_EBP, &contextPointers->Ebp);
+ GetContextPointer(cursor, unwContext, UNW_X86_ESI, &contextPointers->Esi);
+ GetContextPointer(cursor, unwContext, UNW_X86_EDI, &contextPointers->Edi);
#elif defined(_ARM_)
GetContextPointer(cursor, unwContext, UNW_ARM_R4, &contextPointers->R4);
GetContextPointer(cursor, unwContext, UNW_ARM_R5, &contextPointers->R5);
@@ -221,15 +248,34 @@ static void GetContextPointers(unw_cursor_t *cursor, unw_context_t *unwContext,
#endif
}
+extern int g_common_signal_handler_context_locvar_offset;
+
BOOL PAL_VirtualUnwind(CONTEXT *context, KNONVOLATILE_CONTEXT_POINTERS *contextPointers)
{
int st;
unw_context_t unwContext;
unw_cursor_t cursor;
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(_ARM64_) || defined(_ARM_)
- DWORD64 curPc;
-#endif
+ DWORD64 curPc = CONTEXTGetPC(context);
+
+#ifndef __APPLE__
+ // Check if the PC is the return address from the SEHProcessException in the common_signal_handler.
+ // If that's the case, extract its local variable containing the native_context_t of the hardware
+ // exception and return that. This skips the hardware signal handler trampoline that the libunwind
+ // cannot cross on some systems.
+ if ((void*)curPc == g_SEHProcessExceptionReturnAddress)
+ {
+ ULONG contextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_FLOATING_POINT | CONTEXT_EXCEPTION_ACTIVE;
+
+ #if defined(_AMD64_)
+ contextFlags |= CONTEXT_XSTATE;
+ #endif
+ size_t nativeContext = *(size_t*)(CONTEXTGetFP(context) + g_common_signal_handler_context_locvar_offset);
+ CONTEXTFromNativeContext((const native_context_t *)nativeContext, context, contextFlags);
+
+ return TRUE;
+ }
+#endif
if ((context->ContextFlags & CONTEXT_EXCEPTION_ACTIVE) != 0)
{
@@ -240,7 +286,7 @@ BOOL PAL_VirtualUnwind(CONTEXT *context, KNONVOLATILE_CONTEXT_POINTERS *contextP
// So we compensate it by incrementing the PC before passing it to the unwinder.
// Without it, the unwinder would not find unwind info if the hardware exception
// happened in the first instruction of a function.
- CONTEXTSetPC(context, CONTEXTGetPC(context) + 1);
+ CONTEXTSetPC(context, curPc + 1);
}
#if !UNWIND_CONTEXT_IS_UCONTEXT_T
@@ -264,18 +310,6 @@ BOOL PAL_VirtualUnwind(CONTEXT *context, KNONVOLATILE_CONTEXT_POINTERS *contextP
WinContextToUnwindCursor(context, &cursor);
#endif
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(_ARM64_) || defined(_ARM_)
- // FreeBSD, NetBSD and OSX appear to do two different things when unwinding
- // 1: If it reaches where it cannot unwind anymore, say a
- // managed frame. It wil return 0, but also update the $pc
- // 2: If it unwinds all the way to _start it will return
- // 0 from the step, but $pc will stay the same.
- // The behaviour of libunwind from nongnu.org is to null the PC
- // So we bank the original PC here, so we can compare it after
- // the step
- curPc = CONTEXTGetPC(context);
-#endif
-
st = unw_step(&cursor);
if (st < 0)
{
@@ -303,12 +337,18 @@ BOOL PAL_VirtualUnwind(CONTEXT *context, KNONVOLATILE_CONTEXT_POINTERS *contextP
// Update the passed in windows context to reflect the unwind
//
UnwindContextToWinContext(&cursor, context);
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(_ARM64_) || defined(_ARM_)
+
+ // FreeBSD, NetBSD, OSX and Alpine appear to do two different things when unwinding
+ // 1: If it reaches where it cannot unwind anymore, say a
+ // managed frame. It will return 0, but also update the $pc
+ // 2: If it unwinds all the way to _start it will return
+ // 0 from the step, but $pc will stay the same.
+ // So we detect that here and set the $pc to NULL in that case.
+ // This is the default behavior of the libunwind on Linux.
if (st == 0 && CONTEXTGetPC(context) == curPc)
{
CONTEXTSetPC(context, 0);
}
-#endif
if (contextPointers != NULL)
{
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-18 20:13:37 +0000