Richard Henderson <richard.hender...@linaro.org> writes:
> The EXTRA record allows for additional space to be allocated
> beyon what is currently reserved. Add code to emit and read
> this record type.
>
> Nothing uses extra space yet.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
> ---
> linux-user/signal.c | 74
> +++++++++++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 63 insertions(+), 11 deletions(-)
>
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index f9eef3d753..c31cf0601d 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -1443,6 +1443,15 @@ struct target_fpsimd_context {
> uint64_t vregs[32 * 2]; /* really uint128_t vregs[32] */
> };
>
> +#define TARGET_EXTRA_MAGIC 0x45585401
> +
> +struct target_extra_context {
> + struct target_aarch64_ctx head;
> + uint64_t datap; /* 16-byte aligned pointer to extra space cast to __u64
> */
> + uint32_t size; /* size in bytes of the extra space */
> + uint32_t reserved[3];
> +};
> +
> struct target_rt_sigframe {
> struct target_siginfo info;
> struct target_ucontext uc;
> @@ -1502,6 +1511,15 @@ static void target_setup_fpsimd_record(struct
> target_fpsimd_context *fpsimd,
> }
> }
>
> +static void target_setup_extra_record(struct target_extra_context *extra,
> + uint64_t datap, uint32_t extra_size)
> +{
> + __put_user(TARGET_EXTRA_MAGIC, &extra->head.magic);
> + __put_user(sizeof(struct target_extra_context), &extra->head.size);
> + __put_user(datap, &extra->datap);
> + __put_user(extra_size, &extra->size);
> +}
> +
> static void target_setup_end_record(struct target_aarch64_ctx *end)
> {
> __put_user(0, &end->magic);
> @@ -1554,48 +1572,74 @@ static void target_restore_fpsimd_record(CPUARMState
> *env,
> static int target_restore_sigframe(CPUARMState *env,
> struct target_rt_sigframe *sf)
> {
> - struct target_aarch64_ctx *ctx;
> + struct target_aarch64_ctx *ctx, *extra = NULL;
> struct target_fpsimd_context *fpsimd = NULL;
> + uint64_t extra_datap = 0;
> + bool used_extra = false;
> + bool err = false;
>
> target_restore_general_frame(env, sf);
>
> ctx = (struct target_aarch64_ctx *)sf->uc.tuc_mcontext.__reserved;
> while (ctx) {
> - uint32_t magic, size;
> + uint32_t magic, size, extra_size;
>
> __get_user(magic, &ctx->magic);
> __get_user(size, &ctx->size);
> switch (magic) {
> case 0:
> if (size != 0) {
> - return 1;
> + err = true;
> + goto exit;
> + }
> + if (used_extra) {
> + ctx = NULL;
> + } else {
> + ctx = extra;
> + used_extra = true;
> }
> - ctx = NULL;
> continue;
>
> case TARGET_FPSIMD_MAGIC:
> if (fpsimd || size != sizeof(struct target_fpsimd_context)) {
> - return 1;
> + err = true;
> + goto exit;
> }
> fpsimd = (struct target_fpsimd_context *)ctx;
> break;
>
> + case TARGET_EXTRA_MAGIC:
> + if (extra || size != sizeof(struct target_extra_context)) {
> + err = true;
> + goto exit;
> + }
> + __get_user(extra_datap,
> + &((struct target_extra_context *)ctx)->datap);
> + __get_user(extra_size,
> + &((struct target_extra_context *)ctx)->size);
> + extra = lock_user(VERIFY_READ, extra_datap, extra_size, 0);
> + break;
> +
> default:
> /* Unknown record -- we certainly didn't generate it.
> * Did we in fact get out of sync?
> */
> - return 1;
> + err = true;
> + goto exit;
> }
> ctx = (void *)ctx + size;
> }
>
> /* Require FPSIMD always. */
> - if (!fpsimd) {
> - return 1;
> + if (fpsimd) {
> + target_restore_fpsimd_record(env, fpsimd);
> + } else {
> + err = true;
> }
> - target_restore_fpsimd_record(env, fpsimd);
>
> - return 0;
> + exit:
> + unlock_user(extra, extra_datap, 0);
> + return err;
> }
>
> static abi_ulong get_sigframe(struct target_sigaction *ka, CPUARMState *env)
> @@ -1621,7 +1665,8 @@ static void target_setup_frame(int usig, struct
> target_sigaction *ka,
> CPUARMState *env)
> {
> int size = offsetof(struct target_rt_sigframe,
> uc.tuc_mcontext.__reserved);
> - int fpsimd_ofs, end1_ofs, fr_ofs;
> + int fpsimd_ofs, end1_ofs, fr_ofs, end2_ofs = 0;
> + int extra_ofs = 0, extra_base = 0, extra_size = 0;
> struct target_rt_sigframe *frame;
> struct target_rt_frame_record *fr;
> abi_ulong frame_addr, return_addr;
> @@ -1641,7 +1686,14 @@ static void target_setup_frame(int usig, struct
> target_sigaction *ka,
>
> target_setup_general_frame(frame, env, set);
> target_setup_fpsimd_record((void *)frame + fpsimd_ofs, env);
> + if (extra_ofs) {
> + target_setup_extra_record((void *)frame + extra_ofs,
> + frame_addr + extra_base, extra_size);
> + }
> target_setup_end_record((void *)frame + end1_ofs);
> + if (end2_ofs) {
> + target_setup_end_record((void *)frame + end2_ofs);
> + }
>
> /* Set up the stack frame for unwinding. */
> fr = (void *)frame + fr_ofs;
--
Alex Bennée
