tcg: Merge GETPC and GETRA

The return address argument to the softmmu template helpers was confused.  In the legacy case, we wanted to indicate that there is no return address, and so passed in NULL.  However, we then immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero value, indicating the presence of an (invalid) return address.

Push the GETPC_ADJ subtraction down to the only point it's required:
immediately before use within cpu_restore_state, after all NULL pointer
checks have been completed.  This makes GETPC and GETRA identical.

Remove GETRA as the lesser used macro, replacing all uses with GETPC.

Signed-off-by Richard Henderson <[email protected]>

---

Ben, this should fix the "-2" problem that you reported.  Of course, as also discussed in that thread, this won't fix the whole issue.

r~

---
 cputlb.c                |  6 ++---- include/exec/exec-all.h |  9 +++------ softmmu_template.h      | 32 ++++++-------------------------- target-arm/helper.c     |  6 +++--- target-mips/op_helper.c | 18 +++++++++--------- translate-all.c         |  1 +

 6 files changed, 24 insertions(+), 48 deletions(-)

cputlb.c +0 -0

index d068ee5..3c99c34 100644
@@ -543,10 +543,8 @@ static bool victim_tlb_hit(CPUArchState *env,
 size_t mmu_idx, size_t index,
  #undef MMUSUFFIX

 #define MMUSUFFIX _cmmu

cputlb.c +2 -4

-#undef GETPC_ADJ
-#define GETPC_ADJ 0
-#undef GETRA
-#define GETRA() ((uintptr_t)0)
+#undef GETPC
+#define GETPC() ((uintptr_t)0)

 #define SOFTMMU_CODE_ACCESS

 #define SHIFT 0

include/exec/exec-all.h +0 -0

index acda7b6..6a317db 100644
@@ -335,13 +335,12 @@ static inline void tb_add_jump(TranslationBlock
 *tb, int n,
      tb_next->jmp_list_first = (uintptr_t)tb | n;
  }

-/* GETRA is the true target of the return instruction that we'll execute,
-   defined here for simplicity of defining the follow-up macros.  */ +/* GETPC is the true target of the return instruction that we'll execute.  */
 #if defined(CONFIG_TCG_INTERPRETER)
 extern uintptr_t tci_tb_ptr;

include/exec/exec-all.h +1 -1

-# define GETRA() tci_tb_ptr
+# define GETPC() tci_tb_ptr

 #else

include/exec/exec-all.h +1 -1

-# define GETRA() \
+# define GETPC() \

     ((uintptr_t)__builtin_extract_return_addr(__builtin_return_addre ss(0)))
 #endif

include/exec/exec-all.h +0 -0

@@ -354,8 +353,6 @@ extern uintptr_t tci_tb_ptr;

    smaller than 4 bytes, so we don't worry about special-casing this.  */
 #define GETPC_ADJ   2

include/exec/exec-all.h +0 -2

-#define GETPC()  (GETRA() - GETPC_ADJ)
-

 #if !defined(CONFIG_USER_ONLY)

 struct MemoryRegion *iotlb_to_region(CPUState *cpu,

softmmu_template.h +0 -0

index 284ab2c..4cbb714 100644
@@ -150,9 +150,6 @@ WORD_TYPE helper_le_ld_name(CPUArchState *env,
 target_ulong addr,
      uintptr_t haddr;
      DATA_TYPE res;

-    /* Adjust the given return address.  */
-    retaddr -= GETPC_ADJ;
-
     if (a_bits > 0 && (addr & ((1 << a_bits) - 1)) != 0) { cpu_unaligned_access(ENV_GET_CPU(env), addr, READ_ACCESS_TYPE,
                              mmu_idx, retaddr);

softmmu_template.h +0 -0

@@ -193,10 +190,8 @@ WORD_TYPE helper_le_ld_name(CPUArchState *env,
 target_ulong addr,

     do_unaligned_access:
         addr1 = addr & ~(DATA_SIZE - 1);
         addr2 = addr1 + DATA_SIZE;
-        /* Note the adjustment at the beginning of the function. -           Undo that for the recursion.  */
-        res1 = helper_le_ld_name(env, addr1, oi, retaddr + GETPC_ADJ);
-        res2 = helper_le_ld_name(env, addr2, oi, retaddr + GETPC_ADJ);
+        res1 = helper_le_ld_name(env, addr1, oi, retaddr); +        res2 = helper_le_ld_name(env, addr2, oi, retaddr); shift = (addr & (DATA_SIZE - 1)) * 8;

         /* Little-endian combine.  */

softmmu_template.h +0 -0

@@ -224,9 +219,6 @@ WORD_TYPE helper_be_ld_name(CPUArchState *env,
 target_ulong addr,
      uintptr_t haddr;
      DATA_TYPE res;

-    /* Adjust the given return address.  */
-    retaddr -= GETPC_ADJ;
-
     if (a_bits > 0 && (addr & ((1 << a_bits) - 1)) != 0) { cpu_unaligned_access(ENV_GET_CPU(env), addr, READ_ACCESS_TYPE,
                              mmu_idx, retaddr);

softmmu_template.h +0 -0

@@ -267,10 +259,8 @@ WORD_TYPE helper_be_ld_name(CPUArchState *env,
 target_ulong addr,

     do_unaligned_access:
         addr1 = addr & ~(DATA_SIZE - 1);
         addr2 = addr1 + DATA_SIZE;
-        /* Note the adjustment at the beginning of the function. -           Undo that for the recursion.  */
-        res1 = helper_be_ld_name(env, addr1, oi, retaddr + GETPC_ADJ);
-        res2 = helper_be_ld_name(env, addr2, oi, retaddr + GETPC_ADJ);
+        res1 = helper_be_ld_name(env, addr1, oi, retaddr); +        res2 = helper_be_ld_name(env, addr2, oi, retaddr); shift = (addr & (DATA_SIZE - 1)) * 8;

         /* Big-endian combine.  */

softmmu_template.h +0 -0

@@ -334,9 +324,6 @@ void helper_le_st_name(CPUArchState *env,
 target_ulong addr, DATA_TYPE val,
      int a_bits = get_alignment_bits(get_memop(oi));
      uintptr_t haddr;

-    /* Adjust the given return address.  */
-    retaddr -= GETPC_ADJ;
-
     if (a_bits > 0 && (addr & ((1 << a_bits) - 1)) != 0) { cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE, mmu_idx, retaddr);

softmmu_template.h +1 -3

@@ -391,10 +378,8 @@ void helper_le_st_name(CPUArchState *env,
 target_ulong addr, DATA_TYPE val,
          for (i = 0; i < DATA_SIZE; ++i) {
              /* Little-endian extract.  */
              uint8_t val8 = val >> (i * 8);
-            /* Note the adjustment at the beginning of the function.
-               Undo that for the recursion.  */
              glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
-                                            oi, retaddr +
 GETPC_ADJ);
+                                            oi, retaddr);
          }

         return;
     }

softmmu_template.h +0 -0

@@ -417,9 +402,6 @@ void helper_be_st_name(CPUArchState *env,
 target_ulong addr, DATA_TYPE val,
      int a_bits = get_alignment_bits(get_memop(oi));
      uintptr_t haddr;

-    /* Adjust the given return address.  */
-    retaddr -= GETPC_ADJ;
-
     if (a_bits > 0 && (addr & ((1 << a_bits) - 1)) != 0) { cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE, mmu_idx, retaddr);

softmmu_template.h +1 -3

@@ -474,10 +456,8 @@ void helper_be_st_name(CPUArchState *env,
 target_ulong addr, DATA_TYPE val,
          for (i = 0; i < DATA_SIZE; ++i) {
              /* Big-endian extract.  */
              uint8_t val8 = val >> (((DATA_SIZE - 1) * 8) - (i * 8));
-            /* Note the adjustment at the beginning of the function.
-               Undo that for the recursion.  */
              glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
-                                            oi, retaddr +
 GETPC_ADJ);
+                                            oi, retaddr);
          }

         return;
     }

target-arm/helper.c +0 -0

index bdb842c..915fe0f 100644
@@ -8310,12 +8310,12 @@ void HELPER(dc_zva)(CPUARMState *env,
 uint64_t vaddr_in)
               * this purpose use the actual register value passed to

us
              * so that we get the fault address right. */
-            helper_ret_stb_mmu(env, vaddr_in, 0, oi, GETRA()); +            helper_ret_stb_mmu(env, vaddr_in, 0, oi, GETPC()); /* Now we can populate the other TLB entries, if any */ for (i = 0; i < maxidx; i++) {
                 uint64_t va = vaddr + TARGET_PAGE_SIZE * i; if (va != (vaddr_in & TARGET_PAGE_MASK)) { -                    helper_ret_stb_mmu(env, va, 0, oi, GETRA()); +                    helper_ret_stb_mmu(env, va, 0, oi, GETPC()); }
             }
         }

target-arm/helper.c +1 -1

@@ -8332,7 +8332,7 @@ void HELPER(dc_zva)(CPUARMState *env, uint64_t
 vaddr_in)
           *    bounce buffer was in use
           */
          for (i = 0; i < blocklen; i++) {
-            helper_ret_stb_mmu(env, vaddr + i, 0, oi, GETRA());
+            helper_ret_stb_mmu(env, vaddr + i, 0, oi, GETPC());
          }
      }

 #else

target-mips/op_helper.c +0 -0

index ea2f2ab..7af4c2f 100644
@@ -4122,10 +4122,10 @@ void helper_msa_ld_ ## TYPE(CPUMIPSState
 *env, uint32_t wd,             \
  }

 #if !defined(CONFIG_USER_ONLY)

target-mips/op_helper.c +4 -4

-MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, oi, GETRA())
-MSA_LD_DF(DF_HALF,   h, helper_ret_lduw_mmu, oi, GETRA())
-MSA_LD_DF(DF_WORD,   w, helper_ret_ldul_mmu, oi, GETRA())
-MSA_LD_DF(DF_DOUBLE, d, helper_ret_ldq_mmu,  oi, GETRA())
+MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, oi, GETPC())
+MSA_LD_DF(DF_HALF,   h, helper_ret_lduw_mmu, oi, GETPC())
+MSA_LD_DF(DF_WORD,   w, helper_ret_ldul_mmu, oi, GETPC())
+MSA_LD_DF(DF_DOUBLE, d, helper_ret_ldq_mmu,  oi, GETPC())

 #else
 MSA_LD_DF(DF_BYTE,   b, cpu_ldub_data)
 MSA_LD_DF(DF_HALF,   h, cpu_lduw_data)

target-mips/op_helper.c +0 -0

@@ -4161,17 +4161,17 @@ void helper_msa_st_ ## TYPE(CPUMIPSState
 *env, uint32_t wd,             \
      int mmu_idx = cpu_mmu_index(env, false);				
 \

     int
i;                                                              \
     MEMOP_IDX(DF)
    \
-    ensure_writable_pages(env, addr, mmu_idx, GETRA());                 \
+    ensure_writable_pages(env, addr, mmu_idx, GETPC());                 \
     for (i = 0; i < DF_ELEMENTS(DF); i++)
{                             \
         ST_INSN(env, addr + (i << DF), pwd->TYPE[i], ##__VA_ARGS__);    \
     }
    \
 }

 #if !defined(CONFIG_USER_ONLY)

target-mips/op_helper.c +4 -4

-MSA_ST_DF(DF_BYTE,   b, helper_ret_stb_mmu, oi, GETRA())
-MSA_ST_DF(DF_HALF,   h, helper_ret_stw_mmu, oi, GETRA())
-MSA_ST_DF(DF_WORD,   w, helper_ret_stl_mmu, oi, GETRA())
-MSA_ST_DF(DF_DOUBLE, d, helper_ret_stq_mmu, oi, GETRA())
+MSA_ST_DF(DF_BYTE,   b, helper_ret_stb_mmu, oi, GETPC())
+MSA_ST_DF(DF_HALF,   h, helper_ret_stw_mmu, oi, GETPC())
+MSA_ST_DF(DF_WORD,   w, helper_ret_stl_mmu, oi, GETPC())
+MSA_ST_DF(DF_DOUBLE, d, helper_ret_stq_mmu, oi, GETPC())

 #else
 MSA_ST_DF(DF_BYTE,   b, cpu_stb_data)
 MSA_ST_DF(DF_HALF,   h, cpu_stw_data)

translate-all.c +0 -0

index 0d47c1c..644d081 100644
@@ -299,6 +299,7 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t
 retaddr)
  {
      TranslationBlock *tb;

+    retaddr -= GETPC_ADJ;
     tb = tb_find_pc(retaddr);
     if (tb) {
         cpu_restore_state_from_tb(cpu, tb, retaddr);

The return address argument to the softmmu template helpers was confused. In the legacy case, we wanted to indicate that there is no return address, and so passed in NULL. However, we then immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero value, indicating the presence of an (invalid) return address.

Push the GETPC_ADJ subtraction down to the only point it's required:
immediately before use within cpu_restore_state, after all NULL pointer checks have been completed. This makes GETPC and GETRA identical.

Remove GETRA as the lesser used macro, replacing all uses with GETPC.

Signed-off-by Richard Henderson <[email protected]>

---

Ben, this should fix the "-2" problem that you reported. Of course, as also discussed in that thread, this won't fix the whole issue.

r~

---
 cputlb.c                |  6 ++----
 include/exec/exec-all.h |  9 +++------
 softmmu_template.h      | 32 ++++++--------------------------
 target-arm/helper.c     |  6 +++---
 target-mips/op_helper.c | 18 +++++++++---------
 translate-all.c         |  1 +
 6 files changed, 24 insertions(+), 48 deletions(-)

The return address argument to the softmmu template helpers was confused.  In the legacy case, we wanted to indicate that there is no return address, and so passed in NULL.  However, we then immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero value, indicating the presence of an (invalid) return address.

Push the GETPC_ADJ subtraction down to the only point it's required:
immediately before use within cpu_restore_state, after all NULL pointer
checks have been completed.  This makes GETPC and GETRA identical.

Remove GETRA as the lesser used macro, replacing all uses with GETPC.

Signed-off-by Richard Henderson <[email protected]>

---

Ben, this should fix the "-2" problem that you reported.  Of course, as also discussed in that thread, this won't fix the whole issue.

The return address argument to the softmmu template helpers was confused.  In the legacy case, we wanted to indicate that there is no return address, and so passed in NULL.  However, we then immediately subtracted GETPC_ADJ from NULL, resulting in a non-zero value, indicating the presence of an (invalid) return address.

Push the GETPC_ADJ subtraction down to the only point it's required:
immediately before use within cpu_restore_state, after all NULL pointer
checks have been completed.  This makes GETPC and GETRA identical.

Remove GETRA as the lesser used macro, replacing all uses with GETPC.

Signed-off-by Richard Henderson <[email protected]>

---

I'm not sure if there are other cases with softmmu for example, where we do get an exact host PC and thus where the -2 might take us back too far.

I don't see your patch upstream yet so feel free to fold my change into yours.