From 948947dec848b60ed5c68237e9f7c117d4129633 Mon Sep 17 00:00:00 2001 From: Sean McBride Date: Mon, 6 Jul 2020 13:33:29 -0400 Subject: [PATCH] chore: merge changes from other branch --- runtime/include/arch/x86_64/context.h | 62 +++++++++++---------------- 1 file changed, 25 insertions(+), 37 deletions(-) diff --git a/runtime/include/arch/x86_64/context.h b/runtime/include/arch/x86_64/context.h index 523b666..7057938 100644 --- a/runtime/include/arch/x86_64/context.h +++ b/runtime/include/arch/x86_64/context.h @@ -7,29 +7,15 @@ #include #include -#define ARCH_NREGS (16 /* GP registers */ + 1 /* for IP */) #define ARCH_SIG_JMP_OFF 8 -/* - * Register strict ordering> - * rax = (regs + 0) = 0(%%reg) - * rbx = (regs + 1) = 8(%%reg) - * rcx = (regs + 2) = 16(%%reg) - * rdx = (regs + 3) = 24(%%reg) - * rbp = (regs + 4) = 32(%%reg) - * rsp = (regs + 5) = 40(%%reg) - * rsi = (regs + 6) = 48(%%reg) - * rdi = (regs + 7) = 56(%%reg) - * r8 = (regs + 8) = 64(%%reg) - * r9 = (regs + 9) = 72(%%reg) - * r10 = (regs + 10) = 80(%%reg) - * r11 = (regs + 11) = 88(%%reg) - * r12 = (regs + 12) = 96(%%reg) - * r13 = (regs + 13) = 104(%%reg) - * r14 = (regs + 14) = 112(%%reg) - * r15 = (regs + 15) = 120(%%reg) - * rip = (regs + 16) = 128(%%reg) - */ +// Userspace Registers. +enum UREGS +{ + UREG_RSP, + UREG_RIP, + UREG_COUNT +}; typedef uint64_t reg_t; @@ -39,7 +25,7 @@ typedef uint64_t reg_t; */ struct arch_context { - reg_t regs[ARCH_NREGS]; + reg_t regs[UREG_COUNT]; mcontext_t mctx; }; @@ -51,7 +37,7 @@ extern __thread arch_context_t worker_thread_base_context; static void __attribute__((noinline)) arch_context_init(arch_context_t *actx, reg_t ip, reg_t sp) { memset(&actx->mctx, 0, sizeof(mcontext_t)); - memset((void *)actx->regs, 0, sizeof(reg_t) * ARCH_NREGS); + memset((void *)actx->regs, 0, sizeof(reg_t) * UREG_COUNT); if (sp) { /* @@ -71,8 +57,8 @@ static void __attribute__((noinline)) arch_context_init(arch_context_t *actx, re : "memory", "cc", "rbx"); } - *(actx->regs + 5) = sp; - *(actx->regs + 16) = ip; + actx->regs[UREG_RSP] = sp; + actx->regs[UREG_RIP] = ip; } /** @@ -88,12 +74,14 @@ arch_mcontext_restore(mcontext_t *mc, arch_context_t *ctx) { assert(ctx != &worker_thread_base_context); - /* if ctx->regs[5] is set, this was last in a user-level context switch state */ - bool did_user_level_context_switch = ctx->regs[5]; + /* if ctx->regs[0] is set, this was last in a user-level context switch state! + * else restore mcontext.. + */ + bool did_user_level_context_switch = ctx->regs[UREG_RSP]; if (did_user_level_context_switch) { - mc->gregs[REG_RSP] = ctx->regs[5]; - mc->gregs[REG_RIP] = ctx->regs[16] + ARCH_SIG_JMP_OFF; - ctx->regs[5] = 0; + mc->gregs[REG_RSP] = ctx->regs[UREG_RSP]; + mc->gregs[REG_RIP] = ctx->regs[UREG_RIP] + ARCH_SIG_JMP_OFF; + ctx->regs[UREG_RSP] = 0; return 1; } @@ -115,7 +103,7 @@ arch_mcontext_save(arch_context_t *ctx, mcontext_t *mc) { assert(ctx != &worker_thread_base_context); - ctx->regs[5] = 0; + ctx->regs[UREG_RSP] = 0; memcpy(&ctx->mctx, mc, sizeof(mcontext_t)); } @@ -142,17 +130,17 @@ arch_context_switch(arch_context_t *current, arch_context_t *next) asm volatile("pushq %%rbp\n\t" "movq %%rsp, %%rbp\n\t" - "movq $2f, 128(%%rax)\n\t" - "movq %%rsp, 40(%%rax)\n\t" - "cmpq $0, 40(%%rbx)\n\t" + "movq $2f, 8(%%rax)\n\t" + "movq %%rsp, (%%rax)\n\t" + "cmpq $0, (%%rbx)\n\t" "je 1f\n\t" - "movq 40(%%rbx), %%rsp\n\t" - "jmpq *128(%%rbx)\n\t" + "movq (%%rbx), %%rsp\n\t" + "jmpq *8(%%rbx)\n\t" "1:\n\t" "call worker_thread_sandbox_switch_preempt\n\t" ".align 8\n\t" "2:\n\t" - "movq $0, 40(%%rbx)\n\t" + "movq $0, (%%rbx)\n\t" ".align 8\n\t" "3:\n\t" "popq %%rbp\n\t"