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[libunwind][Haiku] Fix signal frame unwinding (#135367)

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The current unwinding implementation on Haiku is messy and broken.
1. It searches weird paths for private headers, which is breaking builds
in consuming projects, such as dotnet/runtime.
2. It does not even work, due to relying on incorrect private offsets.

This commit strips all references to private headers and ports a working
signal frame implementation. It has been tested against
`tests/signal_unwind.pass.cpp` and can go pass the signal frame.
This commit is contained in:
Trung Nguyen
2025-05-29 12:18:55 +10:00
committed by GitHub
parent 7e1a88b9d1
commit 1d9ef8211f
2 changed files with 100 additions and 77 deletions
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16
libunwind/src/CMakeLists.txt
View File

@@ -118,22 +118,6 @@ if (HAIKU)
add_compile_flags("-D_DEFAULT_SOURCE")
add_compile_flags("-DPT_GNU_EH_FRAME=PT_EH_FRAME")
find_path(LIBUNWIND_HAIKU_PRIVATE_HEADERS
"commpage_defs.h"
PATHS ${CMAKE_SYSTEM_INCLUDE_PATH}
PATH_SUFFIXES "/private/system"
NO_DEFAULT_PATH
REQUIRED)
include_directories(SYSTEM "${LIBUNWIND_HAIKU_PRIVATE_HEADERS}")
if (LIBUNWIND_TARGET_TRIPLE)
if (${LIBUNWIND_TARGET_TRIPLE} MATCHES "^x86_64")
include_directories(SYSTEM "${LIBUNWIND_HAIKU_PRIVATE_HEADERS}/arch/x86_64")
endif()
else()
include_directories(SYSTEM "${LIBUNWIND_HAIKU_PRIVATE_HEADERS}/arch/${CMAKE_SYSTEM_PROCESSOR}")
endif()
endif ()
string(REPLACE ";" " " LIBUNWIND_COMPILE_FLAGS "${LIBUNWIND_COMPILE_FLAGS}")

161
libunwind/src/UnwindCursor.hpp
View File

@@ -41,6 +41,12 @@
#define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
#endif
#if defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64)
#include <OS.h>
#include <signal.h>
#define _LIBUNWIND_CHECK_HAIKU_SIGRETURN 1
#endif
#include "AddressSpace.hpp"
#include "CompactUnwinder.hpp"
#include "config.h"
@@ -1031,7 +1037,7 @@ private:
template <typename Registers> int stepThroughSigReturn(Registers &) {
return UNW_STEP_END;
}
#elif defined(_LIBUNWIND_TARGET_HAIKU)
#elif defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
bool setInfoForSigReturn();
int stepThroughSigReturn();
#endif
@@ -2630,7 +2636,7 @@ int UnwindCursor<A, R>::stepWithTBTable(pint_t pc, tbtable *TBTable,
template <typename A, typename R>
void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
defined(_LIBUNWIND_TARGET_HAIKU)
defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
_isSigReturn = false;
#endif
@@ -2755,7 +2761,7 @@ void UnwindCursor<A, R>::setInfoBasedOnIPRegister(bool isReturnAddress) {
#endif // #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
defined(_LIBUNWIND_TARGET_HAIKU)
defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
if (setInfoForSigReturn())
return;
#endif
@@ -2831,63 +2837,6 @@ int UnwindCursor<A, R>::stepThroughSigReturn(Registers_arm64 &) {
_isSignalFrame = true;
return UNW_STEP_SUCCESS;
}
#elif defined(_LIBUNWIND_TARGET_HAIKU) && defined(_LIBUNWIND_TARGET_X86_64)
#include <commpage_defs.h>
#include <signal.h>
extern "C" {
extern void *__gCommPageAddress;
}
template <typename A, typename R>
bool UnwindCursor<A, R>::setInfoForSigReturn() {
#if defined(_LIBUNWIND_TARGET_X86_64)
addr_t signal_handler =
(((addr_t *)__gCommPageAddress)[COMMPAGE_ENTRY_X86_SIGNAL_HANDLER] +
(addr_t)__gCommPageAddress);
addr_t signal_handler_ret = signal_handler + 45;
#endif
pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
if (pc == signal_handler_ret) {
_info = {};
_info.start_ip = signal_handler;
_info.end_ip = signal_handler_ret;
_isSigReturn = true;
return true;
}
return false;
}
template <typename A, typename R>
int UnwindCursor<A, R>::stepThroughSigReturn() {
_isSignalFrame = true;
pint_t sp = _registers.getSP();
#if defined(_LIBUNWIND_TARGET_X86_64)
vregs *regs = (vregs *)(sp + 0x70);
_registers.setRegister(UNW_REG_IP, regs->rip);
_registers.setRegister(UNW_REG_SP, regs->rsp);
_registers.setRegister(UNW_X86_64_RAX, regs->rax);
_registers.setRegister(UNW_X86_64_RDX, regs->rdx);
_registers.setRegister(UNW_X86_64_RCX, regs->rcx);
_registers.setRegister(UNW_X86_64_RBX, regs->rbx);
_registers.setRegister(UNW_X86_64_RSI, regs->rsi);
_registers.setRegister(UNW_X86_64_RDI, regs->rdi);
_registers.setRegister(UNW_X86_64_RBP, regs->rbp);
_registers.setRegister(UNW_X86_64_R8, regs->r8);
_registers.setRegister(UNW_X86_64_R9, regs->r9);
_registers.setRegister(UNW_X86_64_R10, regs->r10);
_registers.setRegister(UNW_X86_64_R11, regs->r11);
_registers.setRegister(UNW_X86_64_R12, regs->r12);
_registers.setRegister(UNW_X86_64_R13, regs->r13);
_registers.setRegister(UNW_X86_64_R14, regs->r14);
_registers.setRegister(UNW_X86_64_R15, regs->r15);
// TODO: XMM
#endif
return UNW_STEP_SUCCESS;
}
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
// defined(_LIBUNWIND_TARGET_AARCH64)
@@ -3103,6 +3052,96 @@ int UnwindCursor<A, R>::stepThroughSigReturn(Registers_s390x &) {
#endif // defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) &&
// defined(_LIBUNWIND_TARGET_S390X)
#if defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
template <typename A, typename R>
bool UnwindCursor<A, R>::setInfoForSigReturn() {
Dl_info dlinfo;
const auto isSignalHandler = [&](pint_t addr) {
if (!dladdr(reinterpret_cast<void *>(addr), &dlinfo))
return false;
if (strcmp(dlinfo.dli_fname, "commpage"))
return false;
if (dlinfo.dli_sname == NULL ||
strcmp(dlinfo.dli_sname, "commpage_signal_handler"))
return false;
return true;
};
pint_t pc = static_cast<pint_t>(this->getReg(UNW_REG_IP));
if (!isSignalHandler(pc))
return false;
pint_t start = reinterpret_cast<pint_t>(dlinfo.dli_saddr);
static size_t signalHandlerSize = 0;
if (signalHandlerSize == 0) {
size_t boundLow = 0;
size_t boundHigh = static_cast<size_t>(-1);
area_info areaInfo;
if (get_area_info(area_for(dlinfo.dli_saddr), &areaInfo) == B_OK)
boundHigh = areaInfo.size;
while (boundLow < boundHigh) {
size_t boundMid = boundLow + ((boundHigh - boundLow) / 2);
pint_t test = start + boundMid;
if (test >= start && isSignalHandler(test))
boundLow = boundMid + 1;
else
boundHigh = boundMid;
}
signalHandlerSize = boundHigh;
}
_info = {};
_info.start_ip = start;
_info.end_ip = start + signalHandlerSize;
_isSigReturn = true;
return true;
}
template <typename A, typename R>
int UnwindCursor<A, R>::stepThroughSigReturn() {
_isSignalFrame = true;
#if defined(_LIBUNWIND_TARGET_X86_64)
// Layout of the stack before function call:
// - signal_frame_data
// + siginfo_t (public struct, fairly stable)
// + ucontext_t (public struct, fairly stable)
// - mcontext_t -> Offset 0x70, this is what we want.
// - frame->ip (8 bytes)
// - frame->bp (8 bytes). Not written by the kernel,
// but the signal handler has a "push %rbp" instruction.
pint_t bp = this->getReg(UNW_X86_64_RBP);
vregs *regs = (vregs *)(bp + 0x70);
_registers.setRegister(UNW_REG_IP, regs->rip);
_registers.setRegister(UNW_REG_SP, regs->rsp);
_registers.setRegister(UNW_X86_64_RAX, regs->rax);
_registers.setRegister(UNW_X86_64_RDX, regs->rdx);
_registers.setRegister(UNW_X86_64_RCX, regs->rcx);
_registers.setRegister(UNW_X86_64_RBX, regs->rbx);
_registers.setRegister(UNW_X86_64_RSI, regs->rsi);
_registers.setRegister(UNW_X86_64_RDI, regs->rdi);
_registers.setRegister(UNW_X86_64_RBP, regs->rbp);
_registers.setRegister(UNW_X86_64_R8, regs->r8);
_registers.setRegister(UNW_X86_64_R9, regs->r9);
_registers.setRegister(UNW_X86_64_R10, regs->r10);
_registers.setRegister(UNW_X86_64_R11, regs->r11);
_registers.setRegister(UNW_X86_64_R12, regs->r12);
_registers.setRegister(UNW_X86_64_R13, regs->r13);
_registers.setRegister(UNW_X86_64_R14, regs->r14);
_registers.setRegister(UNW_X86_64_R15, regs->r15);
// TODO: XMM
#endif // defined(_LIBUNWIND_TARGET_X86_64)
return UNW_STEP_SUCCESS;
}
#endif // defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
(void)stage2;
// Bottom of stack is defined is when unwind info cannot be found.
@@ -3112,7 +3151,7 @@ template <typename A, typename R> int UnwindCursor<A, R>::step(bool stage2) {
// Use unwinding info to modify register set as if function returned.
int result;
#if defined(_LIBUNWIND_CHECK_LINUX_SIGRETURN) || \
defined(_LIBUNWIND_TARGET_HAIKU)
defined(_LIBUNWIND_CHECK_HAIKU_SIGRETURN)
if (_isSigReturn) {
result = this->stepThroughSigReturn();
} else