Re: [PATCH v2 01/15] linux-user/s390x: Fix sigframe types

[David Hildenbrand <david@redhat.com>]

On 28.04.21 21:33, Richard Henderson wrote:
> Noticed via gitlab clang-user job:
> 
>    TEST    signals on s390x
> ../linux-user/s390x/signal.c:258:9: runtime error: \
>    1.84467e+19 is outside the range of representable values of \
>    type 'unsigned long'
> 
> Which points to the fact that we were performing a double-to-uint64_t
> conversion while storing the fp registers, instead of just copying
> the data across.
> 
> Turns out there are several errors:
> 
> target_ulong is the size of the target register, whereas abi_ulong
> is the target 'unsigned long' type.  Not a big deal here, since we
> only support 64-bit s390x, but not correct either.
> 
> In target_sigcontext and target ucontext, we used a host pointer
> instead of a target pointer, aka abi_ulong.
> 
> Fixing this allows the removal of a cast to __put_user.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/s390x/signal.c | 26 +++++++++++++-------------
>   1 file changed, 13 insertions(+), 13 deletions(-)
> 
> diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c
> index b68b44ae7e..707fb603d7 100644
> --- a/linux-user/s390x/signal.c
> +++ b/linux-user/s390x/signal.c
> @@ -37,13 +37,14 @@
>   
>   typedef struct {
>       target_psw_t psw;
> -    target_ulong gprs[__NUM_GPRS];
> -    unsigned int acrs[__NUM_ACRS];
> +    abi_ulong gprs[__NUM_GPRS];
> +    abi_uint acrs[__NUM_ACRS];
>   } target_s390_regs_common;
>   
>   typedef struct {
> -    unsigned int fpc;
> -    double   fprs[__NUM_FPRS];
> +    uint32_t fpc;
> +    uint32_t pad;
> +    uint64_t fprs[__NUM_FPRS];
>   } target_s390_fp_regs;
>   
>   typedef struct {
> @@ -51,22 +52,22 @@ typedef struct {
>       target_s390_fp_regs     fpregs;
>   } target_sigregs;
>   
> -struct target_sigcontext {
> -    target_ulong   oldmask[_SIGCONTEXT_NSIG_WORDS];
> -    target_sigregs *sregs;
> -};
> +typedef struct {
> +    abi_ulong oldmask[_SIGCONTEXT_NSIG_WORDS];
> +    abi_ulong sregs;
> +} target_sigcontext;
>   
>   typedef struct {
>       uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
> -    struct target_sigcontext sc;
> +    target_sigcontext sc;
>       target_sigregs sregs;
>       int signo;
>       uint8_t retcode[S390_SYSCALL_SIZE];
>   } sigframe;
>   
>   struct target_ucontext {
> -    target_ulong tuc_flags;
> -    struct target_ucontext *tuc_link;
> +    abi_ulong tuc_flags;
> +    abi_ulong tuc_link;
>       target_stack_t tuc_stack;
>       target_sigregs tuc_mcontext;
>       target_sigset_t tuc_sigmask;   /* mask last for extensibility */
> @@ -143,8 +144,7 @@ void setup_frame(int sig, struct target_sigaction *ka,
>   
>       save_sigregs(env, &frame->sregs);
>   
> -    __put_user((abi_ulong)(unsigned long)&frame->sregs,
> -               (abi_ulong *)&frame->sc.sregs);
> +    __put_user((abi_ulong)(unsigned long)&frame->sregs, &frame->sc.sregs);
>   
>       /* Set up to return from userspace.  If provided, use a stub
>          already in userspace.  */
> 

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Thanks,

David / dhildenb