Changeset 101258 in vbox for trunk

Timestamp:

Sep 25, 2023 6:59:49 PM (19 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

159241

Message:

VMM/IEM: Made throw/unwinding work on darwin.arm64. This was a bit of a struggle as some LR pointer authentication seems to be applied while unwinding and I couldn't track it down in the libunwind sources. Assuming it's unconditional for jit code and added the necessary instructions to the prolog and epilog to conform. bugref:10370

Location:

trunk

Files:

• include/iprt/armv8.h (modified) (1 diff)
• src/VBox/VMM/VMMAll/IEMAllN8veRecompiler.cpp (modified) (6 diffs)

trunk/include/iprt/armv8.h

@@ -2213 +2213 @@
 /** A64: Return instruction. */
 #define ARMV8_A64_INSTR_RET         UINT32_C(0xd65f03c0)
+/** A64: Return instruction with LR pointer authentication using SP and key A. */
+#define ARMV8_A64_INSTR_RETAA       UINT32_C(0xd65f0bff)
+/** A64: Return instruction with LR pointer authentication using SP and key B. */
+#define ARMV8_A64_INSTR_RETAB       UINT32_C(0xd65f0fff)
+/** A64: Insert pointer authentication code into X17 using X16 and key B. */
+#define ARMV8_A64_INSTR_PACIB1716   UINT32_C(0xd503215f)
+/** A64: Insert pointer authentication code into LR using SP and key B. */
+#define ARMV8_A64_INSTR_PACIBSP     UINT32_C(0xd503237f)
+/** A64: Insert pointer authentication code into LR using XZR and key B. */
+#define ARMV8_A64_INSTR_PACIBZ      UINT32_C(0xd503235f)
 
 

trunk/src/VBox/VMM/VMMAll/IEMAllN8veRecompiler.cpp

@@ -753 +753 @@
         *Ptr.pb++   = 0;                                    /* Segment selector size. */
     }
+#  ifdef RT_ARCH_AMD64
     Ptr = iemDwarfPutLeb128(Ptr, 1);                        /* Code alignment factor (LEB128 = 1). */
+#  else
+    Ptr = iemDwarfPutLeb128(Ptr, 4);                        /* Code alignment factor (LEB128 = 4). */
+#  endif
     Ptr = iemDwarfPutLeb128(Ptr, -8);                       /* Data alignment factor (LEB128 = -8). */
 #  ifdef RT_ARCH_AMD64
     Ptr = iemDwarfPutUleb128(Ptr, DWREG_AMD64_RA);          /* Return address column (ULEB128) */
 #  elif defined(RT_ARCH_ARM64)
-    Ptr = iemDwarfPutUleb128(Ptr, DWREG_ARM64_PC);          /* Return address column (ULEB128) */
+    Ptr = iemDwarfPutUleb128(Ptr, DWREG_ARM64_LR);          /* Return address column (ULEB128) */
 #  else
 #   error "port me"
@@ -775 +779 @@
     Ptr = iemDwarfPutCfaDefCfa(Ptr, DWREG_ARM64_BP,  16);   /* CFA     = BP + 0x10 - first stack parameter */
     //Ptr = iemDwarfPutCfaDefCfa(Ptr, DWREG_ARM64_SP,  IEMNATIVE_FRAME_VAR_SIZE + IEMNATIVE_FRAME_SAVE_REG_SIZE);
-    Ptr = iemDwarfPutCfaOffset(Ptr, DWREG_ARM64_PC,   1);   /* Ret PC  = [CFA + 1*-8] */
+    Ptr = iemDwarfPutCfaOffset(Ptr, DWREG_ARM64_LR,   1);   /* Ret PC  = [CFA + 1*-8] */
     Ptr = iemDwarfPutCfaOffset(Ptr, DWREG_ARM64_BP,   2);   /* Ret BP  = [CFA + 2*-8] */
     Ptr = iemDwarfPutCfaOffset(Ptr, DWREG_ARM64_X28,  3);   /* X28     = [CFA + 3*-8] */
@@ -788 +792 @@
     Ptr = iemDwarfPutCfaOffset(Ptr, DWREG_ARM64_X19, 12);   /* X19     = [CFA +12*-8] */
     AssertCompile(IEMNATIVE_FRAME_SAVE_REG_SIZE / 8 == 12);
+    /** @todo we we need to do something about clearing DWREG_ARM64_RA_SIGN_STATE or something? */
+#  else
+#   error "port me"
 #  endif
     while ((Ptr.u - PtrCie.u) & 3)
@@ -806 +813 @@
     *Ptr.pu64++ = (uintptr_t)pvChunk;                       /* Absolute start PC of this FDE. */
     *Ptr.pu64++ = pExecMemAllocator->cbChunk;               /* PC range length for this PDE. */
-    //*Ptr.pb++ = DW_CFA_nop; - not required for recent libgcc/glibc.
+#  if 0 /* not requried for recent libunwind.dylib nor recent libgcc/glib. */
+    *Ptr.pb++ = DW_CFA_nop;
+#  endif
     while ((Ptr.u - PtrFde.u) & 3)
         *Ptr.pb++ = DW_CFA_nop;
@@ -1676 +1685 @@
     pu32CodeBuf[off++] = Armv8A64MkInstrAddSub(false /*fSub*/, ARMV8_A64_REG_SP, ARMV8_A64_REG_SP, IEMNATIVE_FRAME_SAVE_REG_SIZE);
 
-    /* ret */
-    pu32CodeBuf[off++] = ARMV8_A64_INSTR_RET;
+    /* retab / ret */
+# ifdef RT_OS_DARWIN /** @todo See todo on pacibsp in the prolog. */
+    if (1)
+        pu32CodeBuf[off++] = ARMV8_A64_INSTR_RETAB;
+    else
+# endif
+        pu32CodeBuf[off++] = ARMV8_A64_INSTR_RET;
 
 #else
@@ -1747 +1761 @@
     AssertReturn(pu32CodeBuf, UINT32_MAX);
 
+# ifdef RT_OS_DARWIN /** @todo This seems to be requirement by libunwind for JIT FDEs. Investigate further as been unable
+                      * to figure out where the BRK following AUTHB*+XPACB* stuff comes from in libunwind.  It's
+                      * definitely the dwarf stepping code, but till found it's very tedious to figure out whether it's
+                      * in any way conditional, so just emitting this instructions now and hoping for the best... */
+    /* pacibsp */
+    pu32CodeBuf[off++] = ARMV8_A64_INSTR_PACIBSP;
+# endif
+
     /* stp x19, x20, [sp, #-IEMNATIVE_FRAME_SAVE_REG_SIZE] ; Allocate space for saving registers and place x19+x20 at the bottom. */
     AssertCompile(IEMNATIVE_FRAME_SAVE_REG_SIZE < 64*8);