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Re: [PATCH for-5.2 3/3] linux-user/sparc: Don't zero high half of PC, N
From: |
Richard Henderson |
Subject: |
Re: [PATCH for-5.2 3/3] linux-user/sparc: Don't zero high half of PC, NPC, PSR in sigreturn |
Date: |
Thu, 5 Nov 2020 14:23:27 -0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 |
On 11/5/20 1:23 PM, Peter Maydell wrote:
> The function do_sigreturn() tries to store the PC, NPC and PSR in
> uint32_t local variables, which implicitly drops the high half of
> these fields for 64-bit guests.
>
> The usual effect was that a guest which used signals would crash on
> return from a signal unless it was lucky enough to take it while the
> PC was in the low 4GB of the address space. In particular, Debian
> /bin/dash and /bin/bash would segfault after executing external
> commands.
>
> Use abi_ulong, which is the type these fields all have in the
> __siginfo_t struct.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> linux-user/sparc/signal.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~