[PATCH 1/2] ntdll: Unwind to the LR register if no unwind info is available
Try to keep the behaviour from ea9f47a767c2 of erroring out if unwinding ends up out of bounds (with pc==lr, where setting pc to lr doesn't progress the unwind), but support unwinding from functions without unwind info. Signed-off-by: Martin Storsjo <martin(a)martin.st> --- dlls/ntdll/signal_arm64.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/dlls/ntdll/signal_arm64.c b/dlls/ntdll/signal_arm64.c index eb451603fe4..c9f44e92d30 100644 --- a/dlls/ntdll/signal_arm64.c +++ b/dlls/ntdll/signal_arm64.c @@ -197,8 +197,16 @@ static NTSTATUS virtual_unwind( ULONG type, DISPATCHER_CONTEXT *dispatch, CONTEX } else { - WARN( "exception data not found in %s\n", debugstr_w(module->BaseDllName.Buffer) ); - return STATUS_INVALID_DISPOSITION; + status = context->Pc != context->u.s.Lr ? + STATUS_SUCCESS : STATUS_INVALID_DISPOSITION; + WARN( "exception data not found in %s for %p, LR %p, status %x\n", + debugstr_w(module->BaseDllName.Buffer), (void*) context->Pc, + (void*) context->u.s.Lr, status ); + dispatch->EstablisherFrame = context->Sp; + dispatch->LanguageHandler = NULL; + context->Pc = context->u.s.Lr; + context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL; + return status; } dispatch->EstablisherFrame = context->u.s.Fp; -- 2.17.1
When a signal is raised in a leaf function (that hasn't backed up the Lr register itself), we need to restore both Pc and Lr separately. This doesn't seem to be possible via libunwind, so add a special case unwinding rule for this function. As we have a special case for the function, we could also just as well skip normal dwarf unwinding for this function altogether and just restore the full context from the stack. Signed-off-by: Martin Storsjo <martin(a)martin.st> --- dlls/ntdll/unix/signal_arm64.c | 62 ++++++++++++++++++++++++++++------ 1 file changed, 51 insertions(+), 11 deletions(-) diff --git a/dlls/ntdll/unix/signal_arm64.c b/dlls/ntdll/unix/signal_arm64.c index e08d6a2ee17..3beef729dca 100644 --- a/dlls/ntdll/unix/signal_arm64.c +++ b/dlls/ntdll/unix/signal_arm64.c @@ -157,6 +157,7 @@ static inline struct arm64_thread_data *arm64_thread_data(void) return (struct arm64_thread_data *)ntdll_get_thread_data()->cpu_data; } +extern void raise_func_trampoline( EXCEPTION_RECORD *rec, CONTEXT *context, void *dispatcher ); /*********************************************************************** * unwind_builtin_dll @@ -276,6 +277,17 @@ NTSTATUS CDECL unwind_builtin_dll( ULONG type, DISPATCHER_CONTEXT *dispatch, CON unw_get_reg( &cursor, UNW_REG_IP, (unw_word_t *)&context->Pc ); context->ContextFlags |= CONTEXT_UNWOUND_TO_CALL; + if (info.start_ip == (unw_word_t)raise_func_trampoline) { + /* raise_func_trampoline has a full CONTEXT stored on the stack; + * restore the original Lr value from there. The function we unwind + * to might be a leaf function that hasn't backed up its own original + * Lr value on the stack. + * We could also just restore the full context here without doing + * unw_step at all. */ + const CONTEXT *next_ctx = (const CONTEXT *) dispatch->EstablisherFrame; + context->u.s.Lr = next_ctx->u.s.Lr; + } + TRACE( "next function pc=%016lx%s\n", context->Pc, rc ? "" : " (last frame)" ); TRACE(" x0=%016lx x1=%016lx x2=%016lx x3=%016lx\n", context->u.s.X0, context->u.s.X1, context->u.s.X2, context->u.s.X3 ); @@ -573,20 +585,49 @@ NTSTATUS WINAPI NtGetContextThread( HANDLE handle, CONTEXT *context ) } -extern void raise_func_trampoline( EXCEPTION_RECORD *rec, CONTEXT *context, void *dispatcher, void *sp ); +/* Note, unwind_builtin_dll above has hardcoded assumptions on how this + * function stores things on the stack; if modified, modify that one in + * sync as well. */ __ASM_GLOBAL_FUNC( raise_func_trampoline, - __ASM_CFI(".cfi_signal_frame\n\t") - "stp x29, x30, [sp, #-0x20]!\n\t" - __ASM_CFI(".cfi_def_cfa_offset 32\n\t") - __ASM_CFI(".cfi_offset 29, -32\n\t") - __ASM_CFI(".cfi_offset 30, -24\n\t") + "stp x29, x30, [sp, #-0x30]!\n\t" + __ASM_CFI(".cfi_def_cfa_offset 48\n\t") + __ASM_CFI(".cfi_offset 29, -48\n\t") + __ASM_CFI(".cfi_offset 30, -40\n\t") + "stp x0, x1, [sp, #0x10]\n\t" + "str x2, [sp, #0x20]\n\t" "mov x29, sp\n\t" __ASM_CFI(".cfi_def_cfa_register 29\n\t") - "str x3, [sp, 0x10]\n\t" __ASM_CFI(".cfi_remember_state\n\t") - __ASM_CFI(".cfi_escape 0x0f,0x03,0x8d,0x10,0x06\n\t") /* CFA */ - __ASM_CFI(".cfi_escape 0x10,0x1d,0x02,0x8d,0x00\n\t") /* x29 */ - __ASM_CFI(".cfi_escape 0x10,0x1e,0x02,0x8d,0x08\n\t") /* x30 */ + + /* Memcpy the context onto the stack */ + "sub sp, sp, #0x390\n\t" + "mov x0, sp\n\t" + "mov x2, #0x390\n\t" + "bl " __ASM_NAME("memcpy") "\n\t" + __ASM_CFI(".cfi_def_cfa 31, 0\n\t") + __ASM_CFI(".cfi_escape 0x0f,0x04,0x8f,0x80,0x02,0x06\n\t") /* CFA, DW_OP_breg31 + 0x100, DW_OP_deref */ + __ASM_CFI(".cfi_escape 0x10,0x13,0x03,0x8f,0xa0,0x01\n\t") /* x19, DW_OP_breg31 + 0xA0 */ + __ASM_CFI(".cfi_escape 0x10,0x14,0x03,0x8f,0xa8,0x01\n\t") /* x20 */ + __ASM_CFI(".cfi_escape 0x10,0x15,0x03,0x8f,0xb0,0x01\n\t") /* x21 */ + __ASM_CFI(".cfi_escape 0x10,0x16,0x03,0x8f,0xb8,0x01\n\t") /* x22 */ + __ASM_CFI(".cfi_escape 0x10,0x17,0x03,0x8f,0xc0,0x01\n\t") /* x23 */ + __ASM_CFI(".cfi_escape 0x10,0x18,0x03,0x8f,0xc8,0x01\n\t") /* x24 */ + __ASM_CFI(".cfi_escape 0x10,0x19,0x03,0x8f,0xd0,0x01\n\t") /* x25 */ + __ASM_CFI(".cfi_escape 0x10,0x1a,0x03,0x8f,0xd8,0x01\n\t") /* x26 */ + __ASM_CFI(".cfi_escape 0x10,0x1b,0x03,0x8f,0xe0,0x01\n\t") /* x27 */ + __ASM_CFI(".cfi_escape 0x10,0x1c,0x03,0x8f,0xe8,0x01\n\t") /* x28 */ + __ASM_CFI(".cfi_escape 0x10,0x1d,0x03,0x8f,0xf0,0x01\n\t") /* x29 */ + __ASM_CFI(".cfi_escape 0x10,0x1e,0x03,0x8f,0x88,0x02\n\t") /* x30 = pc */ + __ASM_CFI(".cfi_escape 0x10,0x48,0x03,0x8f,0x90,0x03\n\t") /* d8 */ + __ASM_CFI(".cfi_escape 0x10,0x49,0x03,0x8f,0x98,0x03\n\t") /* d9 */ + __ASM_CFI(".cfi_escape 0x10,0x4a,0x03,0x8f,0xa0,0x03\n\t") /* d10 */ + __ASM_CFI(".cfi_escape 0x10,0x4b,0x03,0x8f,0xa8,0x03\n\t") /* d11 */ + __ASM_CFI(".cfi_escape 0x10,0x4c,0x03,0x8f,0xb0,0x03\n\t") /* d12 */ + __ASM_CFI(".cfi_escape 0x10,0x4d,0x03,0x8f,0xb8,0x03\n\t") /* d13 */ + __ASM_CFI(".cfi_escape 0x10,0x4e,0x03,0x8f,0xc0,0x03\n\t") /* d14 */ + __ASM_CFI(".cfi_escape 0x10,0x4f,0x03,0x8f,0xc8,0x03\n\t") /* d15 */ + "ldp x0, x1, [x29, #0x10]\n\t" + "ldr x2, [x29, #0x20]\n\t" "blr x2\n\t" __ASM_CFI(".cfi_restore_state\n\t") "brk #1") @@ -625,7 +666,6 @@ static void setup_exception( ucontext_t *sigcontext, EXCEPTION_RECORD *rec ) stack->rec = *rec; stack->context = context; - REGn_sig(3, sigcontext) = SP_sig(sigcontext); /* original stack pointer, fourth arg for raise_func_trampoline */ SP_sig(sigcontext) = (ULONG_PTR)stack; LR_sig(sigcontext) = PC_sig(sigcontext); PC_sig(sigcontext) = (ULONG_PTR)raise_func_trampoline; -- 2.17.1
Hi, While running your changed tests, I think I found new failures. Being a bot and all I'm not very good at pattern recognition, so I might be wrong, but could you please double-check? Full results can be found at: https://testbot.winehq.org/JobDetails.pl?Key=79867 Your paranoid android. === debiant (32 bit report) === ntdll: change.c:241: Test failed: should be ready change.c:247: Test failed: action wrong change.c:277: Test failed: should be ready change.c:280: Test failed: info not set change.c:293: Test failed: status set too soon change.c:294: Test failed: info set too soon === debiant (build log) === The task timed out === debiant (build log) === The task timed out
Hi, While running your changed tests, I think I found new failures. Being a bot and all I'm not very good at pattern recognition, so I might be wrong, but could you please double-check? Full results can be found at: https://testbot.winehq.org/JobDetails.pl?Key=79866 Your paranoid android. === debiant (build log) === The task timed out === debiant (build log) === The task timed out
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Martin Storsjo -
Marvin