[Qemu-devel] [PATCH 0/2] Fix armeb-linux-user disassembly

[Qemu-devel] [PATCH 0/2] Fix armeb-linux-user disassembly

[Richard Henderson]

Reported in 
  https://bugs.launchpad.net/qemu/+bug/1724485

There's one existing bug here, wrt setting INSN_ARM_BE32, and
another when it comes to the capstone disassembler patch set.


r~


Richard Henderson (2):
  target/arm: Move BE32 disassembler fixup
  target/arm: Don't set INSN_ARM_BE32 for CONFIG_USER_ONLY

 include/disas/bfd.h |  7 -------
 disas/arm.c         | 21 ++++++++++++++++-----
 target/arm/cpu.c    | 28 +++++++---------------------
 3 files changed, 23 insertions(+), 33 deletions(-)

-- 
2.13.6

[Qemu-devel] [PATCH 1/2] target/arm: Move BE32 disassembler fixup

[Richard Henderson]

The Capstone disassembler has its own big-endian fixup.
Doing this twice does not work, of course.  Move our current
fixup from target/arm/cpu.c to disas/arm.c.

This makes read_memory_inner_func unused and can be removed.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/disas/bfd.h |  7 -------
 disas/arm.c         | 21 ++++++++++++++++-----
 target/arm/cpu.c    | 19 -------------------
 3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/include/disas/bfd.h b/include/disas/bfd.h
index 9b0657cfa9..1f88c9e9d5 100644
--- a/include/disas/bfd.h
+++ b/include/disas/bfd.h
@@ -307,12 +307,6 @@ typedef struct disassemble_info {
     (bfd_vma memaddr, bfd_byte *myaddr, int length,
 	     struct disassemble_info *info);
 
-  /* A place to stash the real read_memory_func if read_memory_func wants to
-     do some funky address arithmetic or similar (e.g. for ARM BE32 mode).  */
-  int (*read_memory_inner_func)
-    (bfd_vma memaddr, bfd_byte *myaddr, int length,
-             struct disassemble_info *info);
-
   /* Function which should be called if we get an error that we can't
      recover from.  STATUS is the errno value from read_memory_func and
      MEMADDR is the address that we were trying to read.  INFO is a
@@ -483,7 +477,6 @@ int generic_symbol_at_address(bfd_vma, struct disassemble_info *);
   (INFO).buffer_vma = 0, \
   (INFO).buffer_length = 0, \
   (INFO).read_memory_func = buffer_read_memory, \
-  (INFO).read_memory_inner_func = NULL, \
   (INFO).memory_error_func = perror_memory, \
   (INFO).print_address_func = generic_print_address, \
   (INFO).print_insn = NULL, \
diff --git a/disas/arm.c b/disas/arm.c
index 27396dd3e1..9967c45990 100644
--- a/disas/arm.c
+++ b/disas/arm.c
@@ -70,6 +70,17 @@ static void floatformat_to_double (unsigned char *data, double *dest)
     *dest = u.f;
 }
 
+static int arm_read_memory(bfd_vma memaddr, bfd_byte *b, int length,
+                           struct disassemble_info *info)
+{
+    assert((info->flags & INSN_ARM_BE32) == 0 || length == 2 || length == 4);
+
+    if ((info->flags & INSN_ARM_BE32) != 0 && length == 2) {
+        memaddr ^= 2;
+    }
+    return info->read_memory_func(memaddr, b, length, info);
+}
+
 /* End of qemu specific additions.  */
 
 struct opcode32
@@ -3810,7 +3821,7 @@ find_ifthen_state (bfd_vma pc, struct disassemble_info *info,
 	  return;
 	}
       addr -= 2;
-      status = info->read_memory_func (addr, (bfd_byte *)b, 2, info);
+      status = arm_read_memory (addr, (bfd_byte *)b, 2, info);
       if (status)
 	return;
 
@@ -3882,7 +3893,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info *info)
       info->bytes_per_chunk = size;
       printer = print_insn_data;
 
-      status = info->read_memory_func (pc, (bfd_byte *)b, size, info);
+      status = arm_read_memory (pc, (bfd_byte *)b, size, info);
       given = 0;
       if (little)
 	for (i = size - 1; i >= 0; i--)
@@ -3899,7 +3910,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info *info)
       info->bytes_per_chunk = 4;
       size = 4;
 
-      status = info->read_memory_func (pc, (bfd_byte *)b, 4, info);
+      status = arm_read_memory (pc, (bfd_byte *)b, 4, info);
       if (little)
 	given = (b[0]) | (b[1] << 8) | (b[2] << 16) | ((unsigned)b[3] << 24);
       else
@@ -3915,7 +3926,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info *info)
       info->bytes_per_chunk = 2;
       size = 2;
 
-      status = info->read_memory_func (pc, (bfd_byte *)b, 2, info);
+      status = arm_read_memory (pc, (bfd_byte *)b, 2, info);
       if (little)
 	given = (b[0]) | (b[1] << 8);
       else
@@ -3929,7 +3940,7 @@ print_insn_arm (bfd_vma pc, struct disassemble_info *info)
 	      || (given & 0xF800) == 0xF000
 	      || (given & 0xF800) == 0xE800)
 	    {
-	      status = info->read_memory_func (pc + 2, (bfd_byte *)b, 2, info);
+	      status = arm_read_memory (pc + 2, (bfd_byte *)b, 2, info);
 	      if (little)
 		given = (b[0]) | (b[1] << 8) | (given << 16);
 	      else
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 1576a6d372..bc9d70df04 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -474,21 +474,6 @@ print_insn_thumb1(bfd_vma pc, disassemble_info *info)
   return print_insn_arm(pc | 1, info);
 }
 
-static int arm_read_memory_func(bfd_vma memaddr, bfd_byte *b,
-                                int length, struct disassemble_info *info)
-{
-    assert(info->read_memory_inner_func);
-    assert((info->flags & INSN_ARM_BE32) == 0 || length == 2 || length == 4);
-
-    if ((info->flags & INSN_ARM_BE32) != 0 && length == 2) {
-        assert(info->endian == BFD_ENDIAN_LITTLE);
-        return info->read_memory_inner_func(memaddr ^ 2, (bfd_byte *)b, 2,
-                                            info);
-    } else {
-        return info->read_memory_inner_func(memaddr, b, length, info);
-    }
-}
-
 static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
 {
     ARMCPU *ac = ARM_CPU(cpu);
@@ -528,10 +513,6 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
         info->endian = BFD_ENDIAN_BIG;
 #endif
     }
-    if (info->read_memory_inner_func == NULL) {
-        info->read_memory_inner_func = info->read_memory_func;
-        info->read_memory_func = arm_read_memory_func;
-    }
     info->flags &= ~INSN_ARM_BE32;
     if (arm_sctlr_b(env)) {
         info->flags |= INSN_ARM_BE32;
-- 
2.13.6

[Qemu-devel] [PATCH 2/2] target/arm: Don't set INSN_ARM_BE32 for CONFIG_USER_ONLY

[Richard Henderson]

This matches translator behaviour in arm_lduw_code.

Fixes: https://bugs.launchpad.net/qemu/+bug/1724485
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index bc9d70df04..a0ed11c9a5 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -478,6 +478,7 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
 {
     ARMCPU *ac = ARM_CPU(cpu);
     CPUARMState *env = &ac->env;
+    bool sctlr_b;
 
     if (is_a64(env)) {
         /* We might not be compiled with the A64 disassembler
@@ -506,7 +507,9 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
         info->cap_arch = CS_ARCH_ARM;
         info->cap_mode = cap_mode;
     }
-    if (bswap_code(arm_sctlr_b(env))) {
+
+    sctlr_b = arm_sctlr_b(env);
+    if (bswap_code(sctlr_b)) {
 #ifdef TARGET_WORDS_BIGENDIAN
         info->endian = BFD_ENDIAN_LITTLE;
 #else
@@ -514,9 +517,11 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
 #endif
     }
     info->flags &= ~INSN_ARM_BE32;
-    if (arm_sctlr_b(env)) {
+#ifndef CONFIG_USER_ONLY
+    if (sctlr_b) {
         info->flags |= INSN_ARM_BE32;
     }
+#endif
 }
 
 uint64_t arm_cpu_mp_affinity(int idx, uint8_t clustersz)
-- 
2.13.6

Re: [Qemu-devel] [PATCH 2/2] target/arm: Don't set INSN_ARM_BE32 for CONFIG_USER_ONLY

[Philippe Mathieu-Daudé]

On 10/19/2017 06:21 PM, Richard Henderson wrote:
> This matches translator behaviour in arm_lduw_code.
> 
> Fixes: https://bugs.launchpad.net/qemu/+bug/1724485
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

> ---
>  target/arm/cpu.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/target/arm/cpu.c b/target/arm/cpu.c
> index bc9d70df04..a0ed11c9a5 100644
> --- a/target/arm/cpu.c
> +++ b/target/arm/cpu.c
> @@ -478,6 +478,7 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
>  {
>      ARMCPU *ac = ARM_CPU(cpu);
>      CPUARMState *env = &ac->env;
> +    bool sctlr_b;
>  
>      if (is_a64(env)) {
>          /* We might not be compiled with the A64 disassembler
> @@ -506,7 +507,9 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
>          info->cap_arch = CS_ARCH_ARM;
>          info->cap_mode = cap_mode;
>      }
> -    if (bswap_code(arm_sctlr_b(env))) {
> +
> +    sctlr_b = arm_sctlr_b(env);
> +    if (bswap_code(sctlr_b)) {
>  #ifdef TARGET_WORDS_BIGENDIAN
>          info->endian = BFD_ENDIAN_LITTLE;
>  #else
> @@ -514,9 +517,11 @@ static void arm_disas_set_info(CPUState *cpu, disassemble_info *info)
>  #endif
>      }
>      info->flags &= ~INSN_ARM_BE32;
> -    if (arm_sctlr_b(env)) {
> +#ifndef CONFIG_USER_ONLY
> +    if (sctlr_b) {
>          info->flags |= INSN_ARM_BE32;
>      }
> +#endif
>  }
>  
>  uint64_t arm_cpu_mp_affinity(int idx, uint8_t clustersz)
>