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 <[email protected]> --- linux-user/signal.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 51 insertions(+), 4 deletions(-) diff --git a/linux-user/signal.c b/linux-user/signal.c index f9eef3d753..ca0ba28c98 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); @@ -1554,14 +1572,16 @@ 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; 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); @@ -1570,7 +1590,12 @@ static int target_restore_sigframe(CPUARMState *env, if (size != 0) { return 1; } - ctx = NULL; + if (used_extra) { + ctx = NULL; + } else { + ctx = extra; + used_extra = true; + } continue; case TARGET_FPSIMD_MAGIC: @@ -1580,6 +1605,17 @@ static int target_restore_sigframe(CPUARMState *env, fpsimd = (struct target_fpsimd_context *)ctx; break; + case TARGET_EXTRA_MAGIC: + if (extra || size != sizeof(struct target_extra_context)) { + return 1; + } + __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? @@ -1595,6 +1631,9 @@ static int target_restore_sigframe(CPUARMState *env, } target_restore_fpsimd_record(env, fpsimd); + if (extra) { + unlock_user(extra, extra_datap, 0); + } return 0; } @@ -1621,7 +1660,8 @@ 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 +1681,14 @@ 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; -- 2.14.3
