chore: merge changes from other branch

main
Sean McBride 4 years ago
parent 02d60a740d
commit 948947dec8

@ -7,29 +7,15 @@
#include <ucontext.h> #include <ucontext.h>
#include <unistd.h> #include <unistd.h>
#define ARCH_NREGS (16 /* GP registers */ + 1 /* for IP */)
#define ARCH_SIG_JMP_OFF 8 #define ARCH_SIG_JMP_OFF 8
/* // Userspace Registers.
* Register strict ordering> enum UREGS
* rax = (regs + 0) = 0(%%reg) {
* rbx = (regs + 1) = 8(%%reg) UREG_RSP,
* rcx = (regs + 2) = 16(%%reg) UREG_RIP,
* rdx = (regs + 3) = 24(%%reg) UREG_COUNT
* 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)
*/
typedef uint64_t reg_t; typedef uint64_t reg_t;
@ -39,7 +25,7 @@ typedef uint64_t reg_t;
*/ */
struct arch_context { struct arch_context {
reg_t regs[ARCH_NREGS]; reg_t regs[UREG_COUNT];
mcontext_t mctx; 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) 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(&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) { if (sp) {
/* /*
@ -71,8 +57,8 @@ static void __attribute__((noinline)) arch_context_init(arch_context_t *actx, re
: "memory", "cc", "rbx"); : "memory", "cc", "rbx");
} }
*(actx->regs + 5) = sp; actx->regs[UREG_RSP] = sp;
*(actx->regs + 16) = ip; 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); assert(ctx != &worker_thread_base_context);
/* if ctx->regs[5] is set, this was last in a user-level context switch state */ /* if ctx->regs[0] is set, this was last in a user-level context switch state!
bool did_user_level_context_switch = ctx->regs[5]; * else restore mcontext..
*/
bool did_user_level_context_switch = ctx->regs[UREG_RSP];
if (did_user_level_context_switch) { if (did_user_level_context_switch) {
mc->gregs[REG_RSP] = ctx->regs[5]; mc->gregs[REG_RSP] = ctx->regs[UREG_RSP];
mc->gregs[REG_RIP] = ctx->regs[16] + ARCH_SIG_JMP_OFF; mc->gregs[REG_RIP] = ctx->regs[UREG_RIP] + ARCH_SIG_JMP_OFF;
ctx->regs[5] = 0; ctx->regs[UREG_RSP] = 0;
return 1; return 1;
} }
@ -115,7 +103,7 @@ arch_mcontext_save(arch_context_t *ctx, mcontext_t *mc)
{ {
assert(ctx != &worker_thread_base_context); assert(ctx != &worker_thread_base_context);
ctx->regs[5] = 0; ctx->regs[UREG_RSP] = 0;
memcpy(&ctx->mctx, mc, sizeof(mcontext_t)); 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" asm volatile("pushq %%rbp\n\t"
"movq %%rsp, %%rbp\n\t" "movq %%rsp, %%rbp\n\t"
"movq $2f, 128(%%rax)\n\t" "movq $2f, 8(%%rax)\n\t"
"movq %%rsp, 40(%%rax)\n\t" "movq %%rsp, (%%rax)\n\t"
"cmpq $0, 40(%%rbx)\n\t" "cmpq $0, (%%rbx)\n\t"
"je 1f\n\t" "je 1f\n\t"
"movq 40(%%rbx), %%rsp\n\t" "movq (%%rbx), %%rsp\n\t"
"jmpq *128(%%rbx)\n\t" "jmpq *8(%%rbx)\n\t"
"1:\n\t" "1:\n\t"
"call worker_thread_sandbox_switch_preempt\n\t" "call worker_thread_sandbox_switch_preempt\n\t"
".align 8\n\t" ".align 8\n\t"
"2:\n\t" "2:\n\t"
"movq $0, 40(%%rbx)\n\t" "movq $0, (%%rbx)\n\t"
".align 8\n\t" ".align 8\n\t"
"3:\n\t" "3:\n\t"
"popq %%rbp\n\t" "popq %%rbp\n\t"

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