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switch: restore x15 register when returning from the fault handler 

Also restore NZCV and FPU registers.
Fixes crash/glitch with YUV converter.
Fixes SoA crash when rendering to a texture.
Issue #1312
This commit is contained in:
Flyinghead 2024-01-17 17:52:26 +01:00
parent c1b087df83
commit 9e37d1e726
2 changed files with 64 additions and 105 deletions
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84
core/linux/libnx_vmem.cpp
View File

@ -266,72 +266,32 @@ void context_switch_aarch64(void* context);
void __libnx_exception_handler(ThreadExceptionDump *ctx)
{
mcontext_t m_ctx;
alignas(16) static ucontext_t u_ctx;
u_ctx.uc_mcontext.pc = ctx->pc.x;
for (int i = 0; i < 29; i++)
u_ctx.uc_mcontext.regs[i] = ctx->cpu_gprs[i].x;
m_ctx.pc = ctx->pc.x;
siginfo_t sig_info;
sig_info.si_addr = (void*)ctx->far.x;
for(int i=0; i<29; i++)
{
// printf("X%d: %p\n", i, ctx->cpu_gprs[i].x);
m_ctx.regs[i] = ctx->cpu_gprs[i].x;
}
fault_handler(0, &sig_info, (void *)&u_ctx);
/*
printf("PC: %p\n", ctx->pc.x);
printf("FP: %p\n", ctx->fp.x);
printf("LR: %p\n", ctx->lr.x);
printf("SP: %p\n", ctx->sp.x);
*/
alignas(16) static uint64_t savedRegisters[66];
uint64_t *ptr = savedRegisters;
// fpu registers (64 bits)
for (int i = 0; i < 32; i++)
ptr[i] = *(u64 *)&ctx->fpu_gprs[i].d;
// cpu gp registers
for (int i = 0; i < 29; i++)
ptr[i + 32] = u_ctx.uc_mcontext.regs[i];
// Special regs
ptr[29 + 32] = ctx->fp.x; // frame pointer
ptr[30 + 32] = ctx->lr.x; // link register
ptr[31 + 32] = ctx->pstate; // sprs
ptr[32 + 32] = ctx->sp.x; // stack pointer
ptr[33 + 32] = u_ctx.uc_mcontext.pc; // PC
ucontext_t u_ctx;
u_ctx.uc_mcontext = m_ctx;
siginfo_t sig_info;
sig_info.si_addr = (void*)ctx->far.x;
fault_handler(0, &sig_info, (void*) &u_ctx);
uint64_t handle[64] = { 0 };
uint64_t *ptr = (uint64_t*)handle;
ptr[0] = m_ctx.regs[0]; /* x0 0 */
ptr[1] = m_ctx.regs[1]; /* x1 8 */
ptr[2] = m_ctx.regs[2]; /* x2 16 */
ptr[3] = m_ctx.regs[3]; /* x3 24 */
ptr[4] = m_ctx.regs[4]; /* x4 32 */
ptr[5] = m_ctx.regs[5]; /* x5 40 */
ptr[6] = m_ctx.regs[6]; /* x6 48 */
ptr[7] = m_ctx.regs[7]; /* x7 56 */
/* Non-volatiles. */
ptr[8] = m_ctx.regs[8]; /* x8 64 */
ptr[9] = m_ctx.regs[9]; /* x9 72 */
ptr[10] = m_ctx.regs[10]; /* x10 80 */
ptr[11] = m_ctx.regs[11]; /* x11 88 */
ptr[12] = m_ctx.regs[12]; /* x12 96 */
ptr[13] = m_ctx.regs[13]; /* x13 104 */
ptr[14] = m_ctx.regs[14]; /* x14 112 */
ptr[15] = m_ctx.regs[15]; /* x15 120 */
ptr[16] = m_ctx.regs[16]; /* x16 128 */
ptr[17] = m_ctx.regs[17]; /* x17 136 */
ptr[18] = m_ctx.regs[18]; /* x18 144 */
ptr[19] = m_ctx.regs[19]; /* x19 152 */
ptr[20] = m_ctx.regs[20]; /* x20 160 */
ptr[21] = m_ctx.regs[21]; /* x21 168 */
ptr[22] = m_ctx.regs[22]; /* x22 176 */
ptr[23] = m_ctx.regs[23]; /* x23 184 */
ptr[24] = m_ctx.regs[24]; /* x24 192 */
ptr[25] = m_ctx.regs[25]; /* x25 200 */
ptr[26] = m_ctx.regs[26]; /* x26 208 */
ptr[27] = m_ctx.regs[27]; /* x27 216 */
ptr[28] = m_ctx.regs[28]; /* x28 224 */
/* Special regs */
ptr[29] = ctx->fp.x; /* frame pointer 232 */
ptr[30] = ctx->lr.x; /* link register 240 */
ptr[31] = ctx->sp.x; /* stack pointer 248 */
ptr[32] = (uintptr_t)ctx->pc.x; /* PC 256 */
context_switch_aarch64(ptr);
context_switch_aarch64(ptr);
}
}
#endif // TARGET_NO_EXCEPTIONS

85
shell/switch/context_switch.S
View File

@ -1,47 +1,46 @@
.hidden context_switch_aarch64
.globl context_switch_aarch64
context_switch_aarch64:
// Setup SP on the Buffer
MOV SP, X0
// Restore FPU regs
ldp d0, d1, [x0, #0x00]
ldp d2, d3, [x0, #0x10]
ldp d4, d5, [x0, #0x20]
ldp d6, d7, [x0, #0x30]
ldp d8, d9, [x0, #0x40]
ldp d10, d11, [x0, #0x50]
ldp d12, d13, [x0, #0x60]
ldp d14, d15, [x0, #0x70]
ldp d16, d17, [x0, #0x80]
ldp d18, d19, [x0, #0x90]
ldp d20, d21, [x0, #0xa0]
ldp d22, d23, [x0, #0xb0]
ldp d24, d25, [x0, #0xc0]
ldp d26, d27, [x0, #0xd0]
ldp d28, d29, [x0, #0xe0]
ldp d30, d31, [x0, #0xf0]
// Restore Regs
LDR X0, [SP, #0]
LDR X1, [SP, #8]
LDR X2, [SP, #16]
LDR X3, [SP, #24]
LDR X4, [SP, #32]
LDR X5, [SP, #40]
LDR X6, [SP, #48]
LDR X7, [SP, #56]
LDR X8, [SP, #64]
LDR X9, [SP, #72]
LDR X10, [SP, #80]
LDR X11, [SP, #88]
LDR X12, [SP, #96]
LDR X13, [SP, #104]
LDR X14, [SP, #112]
LDR X15, [SP, #120]
LDR X16, [SP, #128]
LDR X17, [SP, #136]
LDR X18, [SP, #144]
LDR X19, [SP, #152]
LDR X20, [SP, #160]
LDR X21, [SP, #168]
LDR X22, [SP, #176]
LDR X23, [SP, #184]
LDR X24, [SP, #192]
LDR X25, [SP, #200]
LDR X26, [SP, #208]
LDR X27, [SP, #216]
LDR X28, [SP, #224]
// Restore FP, LR, SP
LDR FP, [SP, #232]
LDR LR, [SP, #240]
MOV X15, SP
LDR X17, [X15, #248]
MOV SP, X17
// Branch to PC
LDR X17, [X15, #256]
BR X17
// Restore GPRS regs
ldr x1, [x0, #0x108]
ldp x2, x3, [x0, #0x110]
ldp x4, x5, [x0, #0x120]
ldp x6, x7, [x0, #0x130]
ldp x8, x9, [x0, #0x140]
ldp x10, x11, [x0, #0x150]
ldp x12, x13, [x0, #0x160]
ldp x14, x15, [x0, #0x170]
ldp x16, x17, [x0, #0x180]
ldp x18, x19, [x0, #0x190]
ldp x20, x21, [x0, #0x1a0]
ldp x22, x23, [x0, #0x1b0]
ldp x24, x25, [x0, #0x1c0]
ldp x26, x27, [x0, #0x1d0]
ldp x28, x29, [x0, #0x1e0] // x29 is FP
// Restore special regs and jump
// x16 and x17 are safe to use?
ldp x30, x17, [x0, #0x1f0] // LR, pstate
msr nzcv, x17
ldr x17, [x0, #0x200] // SP
mov sp, x17
ldr x17, [x0, #0x208] // PC
ldr x0, [x0, #0x100]
br x17