On Thu, Oct 14, 2021 at 10:14 PM Richard Henderson < [email protected]> wrote:
> This requires extra work for each target, but adds the > common syscall code, and the necessary flag in CPUState. > > Signed-off-by: Richard Henderson <[email protected]> > --- > include/hw/core/cpu.h | 3 +++ > linux-user/generic/target_prctl_unalign.h | 27 +++++++++++++++++++++++ > cpu.c | 20 ++++++++++++----- > linux-user/syscall.c | 13 +++++++++-- > 4 files changed, 56 insertions(+), 7 deletions(-) > create mode 100644 linux-user/generic/target_prctl_unalign.h > Reviewed-by: Warner Losh <[email protected]> > diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h > index 1a10497af3..6202bbf9c3 100644 > --- a/include/hw/core/cpu.h > +++ b/include/hw/core/cpu.h > @@ -412,6 +412,9 @@ struct CPUState { > > bool ignore_memory_transaction_failures; > > + /* Used for user-only emulation of prctl(PR_SET_UNALIGN). */ > + bool prctl_unalign_sigbus; > + > struct hax_vcpu_state *hax_vcpu; > > struct hvf_vcpu_state *hvf; > diff --git a/linux-user/generic/target_prctl_unalign.h > b/linux-user/generic/target_prctl_unalign.h > new file mode 100644 > index 0000000000..bc3b83af2a > --- /dev/null > +++ b/linux-user/generic/target_prctl_unalign.h > @@ -0,0 +1,27 @@ > +/* > + * Generic prctl unalign functions for linux-user > + * > + * SPDX-License-Identifier: GPL-2.0-or-later > + */ > +#ifndef GENERIC_TARGET_PRCTL_UNALIGN_H > +#define GENERIC_TARGET_PRCTL_UNALIGN_H > + > +static abi_long do_prctl_get_unalign(CPUArchState *env, target_long arg2) > +{ > + CPUState *cs = env_cpu(env); > + uint32_t res = PR_UNALIGN_NOPRINT; > + if (cs->prctl_unalign_sigbus) { > + res |= PR_UNALIGN_SIGBUS; > + } > + return put_user_u32(res, arg2); > +} > +#define do_prctl_get_unalign do_prctl_get_unalign > + > +static abi_long do_prctl_set_unalign(CPUArchState *env, target_long arg2) > +{ > + env_cpu(env)->prctl_unalign_sigbus = arg2 & PR_UNALIGN_SIGBUS; > + return 0; > +} > +#define do_prctl_set_unalign do_prctl_set_unalign > + > +#endif /* GENERIC_TARGET_PRCTL_UNALIGN_H */ > diff --git a/cpu.c b/cpu.c > index 9bce67ef55..9e388d9cd3 100644 > --- a/cpu.c > +++ b/cpu.c > @@ -179,13 +179,23 @@ void cpu_exec_unrealizefn(CPUState *cpu) > cpu_list_remove(cpu); > } > > +/* > + * This can't go in hw/core/cpu.c because that file is compiled only > + * once for both user-mode and system builds. > + */ > static Property cpu_common_props[] = { > -#ifndef CONFIG_USER_ONLY > +#ifdef CONFIG_USER_ONLY > /* > - * Create a memory property for softmmu CPU object, > - * so users can wire up its memory. (This can't go in hw/core/cpu.c > - * because that file is compiled only once for both user-mode > - * and system builds.) The default if no link is set up is to use > + * Create a property for the user-only object, so users can > + * adjust prctl(PR_SET_UNALIGN) from the command-line. > + * Has no effect if the target does not support the feature. > + */ > + DEFINE_PROP_BOOL("prctl-unalign-sigbus", CPUState, > + prctl_unalign_sigbus, false), > +#else > + /* > + * Create a memory property for softmmu CPU object, so users can > + * wire up its memory. The default if no link is set up is to use > * the system address space. > */ > DEFINE_PROP_LINK("memory", CPUState, memory, TYPE_MEMORY_REGION, > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index 7635c2397a..ac3bc8a330 100644 > --- a/linux-user/syscall.c > +++ b/linux-user/syscall.c > @@ -6375,6 +6375,12 @@ static abi_long do_prctl_inval1(CPUArchState *env, > abi_long arg2) > #ifndef do_prctl_get_tagged_addr_ctrl > #define do_prctl_get_tagged_addr_ctrl do_prctl_inval0 > #endif > +#ifndef do_prctl_get_unalign > +#define do_prctl_get_unalign do_prctl_inval1 > +#endif > +#ifndef do_prctl_set_unalign > +#define do_prctl_set_unalign do_prctl_inval1 > +#endif > > static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long > arg2, > abi_long arg3, abi_long arg4, abi_long arg5) > @@ -6438,6 +6444,11 @@ static abi_long do_prctl(CPUArchState *env, > abi_long option, abi_long arg2, > } > return do_prctl_get_tagged_addr_ctrl(env); > > + case PR_GET_UNALIGN: > + return do_prctl_get_unalign(env, arg2); > + case PR_SET_UNALIGN: > + return do_prctl_set_unalign(env, arg2); > + > case PR_GET_DUMPABLE: > case PR_SET_DUMPABLE: > case PR_GET_KEEPCAPS: > @@ -6480,8 +6491,6 @@ static abi_long do_prctl(CPUArchState *env, abi_long > option, abi_long arg2, > case PR_SET_THP_DISABLE: > case PR_GET_TSC: > case PR_SET_TSC: > - case PR_GET_UNALIGN: > - case PR_SET_UNALIGN: > default: > /* Disable to prevent the target disabling stuff we need. */ > return -TARGET_EINVAL; > -- > 2.25.1 > >
