Re: [Qemu-devel] [PATCH v3] linux-user/syscall.c: Handle SH4's exceptional alignment for p{read, write}64

[John Paul Adrian Glaubitz]

(re-sent because GPG messed up the line endings)

On 09/15/2017 09:33 PM, James Clarke wrote:
> Fixes: https://bugs.launchpad.net/qemu/+bug/1716767
> Signed-off-by: James Clarke <address@hidden>
> ---
> 
> Changes since v2:
>  * Fixed opening curly brace formatting, both for my new SH4-specific
>    regpairs_aligned function, as well as the Arm one I touched, to appease
>    checkpatch.pl
> 
> Changes since v1:
>  * Removed all changes in v1 :)
>  * Added syscall num argument to regpairs_aligned
>  * Added SH4-specific implementation of regpairs_aligned to return 1 for
>    p{read,write}64
> 
>  linux-user/syscall.c | 36 +++++++++++++++++++++++++-----------
>  1 file changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 9b6364a266..0c1bd80bed 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -667,18 +667,32 @@ static inline int next_free_host_timer(void)
>  
>  /* ARM EABI and MIPS expect 64bit types aligned even on pairs or registers */
>  #ifdef TARGET_ARM
> -static inline int regpairs_aligned(void *cpu_env) {
> +static inline int regpairs_aligned(void *cpu_env, int num)
> +{
>      return ((((CPUARMState *)cpu_env)->eabi) == 1) ;
>  }
>  #elif defined(TARGET_MIPS) && (TARGET_ABI_BITS == 32)
> -static inline int regpairs_aligned(void *cpu_env) { return 1; }
> +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; }
>  #elif defined(TARGET_PPC) && !defined(TARGET_PPC64)
>  /* SysV AVI for PPC32 expects 64bit parameters to be passed on odd/even pairs
>   * of registers which translates to the same as ARM/MIPS, because we start 
> with
>   * r3 as arg1 */
> -static inline int regpairs_aligned(void *cpu_env) { return 1; }
> +static inline int regpairs_aligned(void *cpu_env, int num) { return 1; }
> +#elif defined(TARGET_SH4)
> +/* SH4 doesn't align register pairs, except for p{read,write}64 */
> +static inline int regpairs_aligned(void *cpu_env, int num)
> +{
> +    switch (num) {
> +    case TARGET_NR_pread64:
> +    case TARGET_NR_pwrite64:
> +        return 1;
> +
> +    default:
> +        return 0;
> +    }
> +}
>  #else
> -static inline int regpairs_aligned(void *cpu_env) { return 0; }
> +static inline int regpairs_aligned(void *cpu_env, int num) { return 0; }
>  #endif
>  
>  #define ERRNO_TABLE_SIZE 1200
> @@ -6857,7 +6871,7 @@ static inline abi_long target_truncate64(void *cpu_env, 
> const char *arg1,
>                                           abi_long arg3,
>                                           abi_long arg4)
>  {
> -    if (regpairs_aligned(cpu_env)) {
> +    if (regpairs_aligned(cpu_env, TARGET_NR_truncate64)) {
>          arg2 = arg3;
>          arg3 = arg4;
>      }
> @@ -6871,7 +6885,7 @@ static inline abi_long target_ftruncate64(void 
> *cpu_env, abi_long arg1,
>                                            abi_long arg3,
>                                            abi_long arg4)
>  {
> -    if (regpairs_aligned(cpu_env)) {
> +    if (regpairs_aligned(cpu_env, TARGET_NR_ftruncate64)) {
>          arg2 = arg3;
>          arg3 = arg4;
>      }
> @@ -10495,7 +10509,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>  #endif
>  #ifdef TARGET_NR_pread64
>      case TARGET_NR_pread64:
> -        if (regpairs_aligned(cpu_env)) {
> +        if (regpairs_aligned(cpu_env, num)) {
>              arg4 = arg5;
>              arg5 = arg6;
>          }
> @@ -10505,7 +10519,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>          unlock_user(p, arg2, ret);
>          break;
>      case TARGET_NR_pwrite64:
> -        if (regpairs_aligned(cpu_env)) {
> +        if (regpairs_aligned(cpu_env, num)) {
>              arg4 = arg5;
>              arg5 = arg6;
>          }
> @@ -11275,7 +11289,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>          arg6 = ret;
>  #else
>          /* 6 args: fd, offset (high, low), len (high, low), advice */
> -        if (regpairs_aligned(cpu_env)) {
> +        if (regpairs_aligned(cpu_env, num)) {
>              /* offset is in (3,4), len in (5,6) and advice in 7 */
>              arg2 = arg3;
>              arg3 = arg4;
> @@ -11294,7 +11308,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>  #ifdef TARGET_NR_fadvise64
>      case TARGET_NR_fadvise64:
>          /* 5 args: fd, offset (high, low), len, advice */
> -        if (regpairs_aligned(cpu_env)) {
> +        if (regpairs_aligned(cpu_env, num)) {
>              /* offset is in (3,4), len in 5 and advice in 6 */
>              arg2 = arg3;
>              arg3 = arg4;
> @@ -11407,7 +11421,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>  #ifdef TARGET_NR_readahead
>      case TARGET_NR_readahead:
>  #if TARGET_ABI_BITS == 32
> -        if (regpairs_aligned(cpu_env)) {
> +        if (regpairs_aligned(cpu_env, num)) {
>              arg2 = arg3;
>              arg3 = arg4;
>              arg4 = arg5;
> 

Tested-By: John Paul Adrian Glaubitz <address@hidden>

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - address@hidden
`. `'   Freie Universitaet Berlin - address@hidden
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913