Hi Richard, (revisiting this old patch.)
On 20/12/21 22:41, Richard Henderson wrote:
This requires extra work for each target, but adds the common syscall code, and the necessary flag in CPUState. Reviewed-by: Warner Losh <i...@bsdimp.com> Signed-off-by: Richard Henderson <richard.hender...@linaro.org> --- 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 diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h index e948e81f1a..76ab3b851c 100644 --- a/include/hw/core/cpu.h +++ b/include/hw/core/cpu.h @@ -413,6 +413,9 @@ 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 945dd3dded..016bf06a1a 100644 --- a/cpu.c +++ b/cpu.c @@ -174,13 +174,23 @@ 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.
How can I test this per-thread property? Shouldn't this be an accel (TCG/user) property, for all threads?
+ * 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 ef7a955dbb..3f481eb5b2 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -6377,6 +6377,12 @@ 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 +#endifstatic abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,abi_long arg3, abi_long arg4, abi_long arg5) @@ -6440,6 +6446,11 @@ 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: @@ -6482,8 +6493,6 @@ 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;
