diff --git a/CODE/login/main.c b/CODE/login/main.c index a8c849a..624bcf2 100644 --- a/CODE/login/main.c +++ b/CODE/login/main.c @@ -14,11 +14,14 @@ #include "../UTSM/include/utsm/dsk.h" -/* 防篡改:linker 导出的 .text 段范围与预期哈希存储位置 */ -extern const u8 __text_start[]; -extern const u8 __text_end[]; -extern const u8 __expected_hash[]; -extern const u8 __expected_hash_end[]; +/* 防篡改:linker 导出的 .text 段范围与预期哈希存储位置。 + * hidden 可见性强制 PIE 下用 lea rip 取址(基址无关),禁止走 GOT—— + * GOT slot 若被 DSK 侧后续 IO 破坏(BUG:ibuf+0x1EAE10 被清零), + * len 将计算成天文数字导致 integrity 误报 LOGIN-E01。 */ +extern const u8 __text_start[] __attribute__((visibility("hidden"))); +extern const u8 __text_end[] __attribute__((visibility("hidden"))); +extern const u8 __expected_hash[] __attribute__((visibility("hidden"))); +extern const u8 __expected_hash_end[] __attribute__((visibility("hidden"))); typedef signed char i8; typedef unsigned char u8; @@ -777,6 +780,20 @@ static void login_mouse_init(void) { } __attribute__((visibility("default"))) +/* [DSK-E70 布局雷区规避 · 白名单登记] + * DSK 加载链路存在未定位的写零破坏:跳转 login 后 image 尾部 + * (ibuf+0x1EAE10 附近,≥ 数百字节)被清零。.text ≤ ~16.5KB 时 + * 雷区覆盖 .got/.bss 关键数据,导致 len 计算错误 → LOGIN-E01 误报; + * .text ≥ ~17KB 时雷区落在 .rodata/logo 数据上无害。 + * 此填充把 .text 显式推入安全布局。根因修复登记 docs/STATUS.md DSK-E70, + * 修复后应删除本函数。 */ +__attribute__((noinline, used)) static void dsk_e70_layout_guard(void) { + /* 1024B nop 序列,编译器不可消除 */ + __asm__ volatile( + ".rept 341\n\tnop\n\tnop\n\tnop\n\t.endr\n" + ::: "memory"); +} + void dsk_entry(const dsk_boot_context *ctx) { __asm__ volatile("cli"); /* prevent IRQ1 (ps2kbd) from racing with our polling */ logl("[login] boot"); @@ -862,13 +879,10 @@ void dsk_entry(const dsk_boot_context *ctx) { pass[0] = 0; int plen = 0; - /* Draw initial UI */ + /* Draw initial UI(draw_login_card 内部已含光标 save+draw, + * 此处不得重复 save——否则会把光标像素当背景存入,移动后留残影) */ draw_login_card(fb, card_x, card_y, pass, 1, msg, msg_color, fg); - /* 初始鼠标光标 */ - cursor_save_bg(fb, g_mouse_x, g_mouse_y); - cursor_draw(fb, g_mouse_x, g_mouse_y); - /* Input loop */ int shift = 0; int release = 0; diff --git a/CODE/login/patch_login_hash.ps1 b/CODE/login/patch_login_hash.ps1 index 518ee86..8902d32 100644 --- a/CODE/login/patch_login_hash.ps1 +++ b/CODE/login/patch_login_hash.ps1 @@ -6,7 +6,7 @@ if (-not (Test-Path $ElfPath)) { Write-Error ("not found: " + $ElfPath); exit 1 $bytes = [System.IO.File]::ReadAllBytes($ElfPath) -# ELF64 header: e_shoff @ 0x28 (u64), e_shentsize @ 0x3A (u16), e_shnum @ 0x3C (u16) +# ELF64 header: e_shoff @ 0x28 (u64), e_shentsize @ 0x3A (u16), e_shnum @ 0x3C (u16), e_shstrndx @ 0x3E (u16) function U64([byte[]]$b, [int]$o) { [UInt64]$b[$o] -bor ([UInt64]$b[$o+1] -shl 8) -bor ([UInt64]$b[$o+2] -shl 16) -bor ([UInt64]$b[$o+3] -shl 24) -bor ([UInt64]$b[$o+4] -shl 32) -bor ([UInt64]$b[$o+5] -shl 40) -bor ([UInt64]$b[$o+6] -shl 48) -bor ([UInt64]$b[$o+7] -shl 56) } function U16([byte[]]$b, [int]$o) { [UInt32]$b[$o] -bor ([UInt32]$b[$o+1] -shl 8) } function U32([byte[]]$b, [int]$o) { [UInt32]$b[$o] -bor ([UInt32]$b[$o+1] -shl 8) -bor ([UInt32]$b[$o+2] -shl 16) -bor ([UInt32]$b[$o+3] -shl 24) } @@ -14,16 +14,30 @@ function U32([byte[]]$b, [int]$o) { [UInt32]$b[$o] -bor ([UInt32]$b[$o+1] -shl 8 $shoff = U64 $bytes 0x28 $shentsize = U16 $bytes 0x3A $shnum = U16 $bytes 0x3C +$shstrndx = U16 $bytes 0x3E $textOff = 0; $textSize = 0; $hashOff = 0 -$shstr = $null -for ($i = 0; $i -lt $shnum; $i++) { - $sh = $shoff + $i * $shentsize - $shType = U32 $bytes ($sh + 4) - $shOffset = U64 $bytes ($sh + 24) - $shSize = U64 $bytes ($sh + 32) - if ($shType -eq 3 -and -not $shstr) { $shstr = $bytes[[int]$shOffset..[int]($shOffset+$shSize-1)] } +# e_shstrndx points at .shstrtab directly — picking the first SHT_STRTAB is wrong +# when .dynsym/.strtab exist (they come before .shstrtab and would garble names) +$shstrHdr = $shoff + $shstrndx * $shentsize +$shstrOff = U64 $bytes ($shstrHdr + 24) +$shstrSize = U64 $bytes ($shstrHdr + 32) +$shstr = $bytes[[int]$shstrOff..[int]($shstrOff+$shstrSize-1)] + +# Hash range = first PT_LOAD segment (offset/filesz). This matches exactly what +# the DSK loader copies into memory and what the runtime hashes via +# __text_start..__text_end (the output section may include tail padding that +# the .text section header's sh_size does not cover — hashing sh_size caused +# LOGIN-E01 integrity FAIL whenever lld emitted padding after .text). +$phoff = U64 $bytes 0x20 +$phentsize = U16 $bytes 0x36 +$phnum = U16 $bytes 0x38 +for ($i = 0; $i -lt $phnum; $i++) { + $ph = $phoff + $i * $phentsize + $pType = U32 $bytes $ph + if ($pType -eq 1) { $textOff = U64 $bytes ($ph + 8); $textSize = U64 $bytes ($ph + 32); break } } +if ($textOff -eq 0) { Write-Error 'PT_LOAD text segment not found'; exit 1 } function Get-SectName([byte[]]$strtab, [int]$idx) { $end = $idx @@ -38,11 +52,10 @@ for ($i = 0; $i -lt $shnum; $i++) { $shOffset = U64 $bytes ($sh + 24) $shSize = U64 $bytes ($sh + 32) $nm = Get-SectName $shstr $nameIdx - if ($nm -eq '.text' -and $shType -eq 1) { $textOff = $shOffset; $textSize = $shSize } if ($nm -eq '.hashseg') { $hashOff = $shOffset } } -if ($textOff -eq 0 -or $hashOff -eq 0) { Write-Error 'section .text/.hashseg not found'; exit 1 } +if ($textOff -eq 0 -or $hashOff -eq 0) { Write-Error 'PT_LOAD text/.hashseg not found'; exit 1 } $sha = [System.Security.Cryptography.SHA256]::Create() $textBytes = New-Object byte[] $textSize diff --git a/docs/STATUS.md b/docs/STATUS.md index 250c945..8da4114 100644 --- a/docs/STATUS.md +++ b/docs/STATUS.md @@ -88,6 +88,15 @@ | 主镜像改挂 SATA(run_qemu.bat) | ✅ | DSK/AHCI 块层必须可见 GPT 盘才能访问 p2 ext4;边车退居 ide.1 | run_qemu.bat | | 开机画面去 Logo | ✅ | 移除 Logo.png 图像,仅保留居中 "DESHAB P01" 文字;dcp/xj logo 改由 TEXTURES/ 重新生成 | build 日志 | +## DSK-E70:ibuf 尾部写零破坏(2026-10-05 · 未解) + +| 项 | 状态 | 说明 | 证据 | +|----|------|------|------| +| 现象 | 🔶 | DSK 经 `dsk_load_elf` 载入 login.elf 并跳转后,image 尾部(ibuf+0x1EAE10 附近,≥ 数百字节)被清零。`.text` ≤ ~16.5KB 时雷区覆盖 .got/.bss 关键数据 → login integrity 校验 len 计算错误 → LOGIN-E01 误报;`.text` ≥ ~17KB 时雷区落在 .rodata 无害 | `.build_tmp/qemu_dbg.log`(boot 矩阵:16248B FAIL×4 / 16504B FAIL×2 / 17352、17608B OK;DSK 侧 checksum 跳转前位精确 + QMP 物理内存 dump 停机后 .text 位精确与 got[0]=0 并存) | +| login 侧加固 | ✅ | ① `__text_start/end/__expected_hash` 加 hidden 可见性 → PIE 下 lea rip 取址,len 计算零 GOT 依赖;② `dsk_e70_layout_guard` 显式将 .text 推入安全布局(白名单登记,根因修复后删除) | CODE/login/main.c | +| patch 侧加固 | ✅ | patch_login_hash.ps1 改按 PT_LOAD filesz 计算 hash 范围(与 DSK loader 加载范围/运行时 [__text_start,__text_end) 严格一致),并用 e_shstrndx 定位 .shstrtab | CODE/login/patch_login_hash.ps1 | +| 根因(写零者) | ⬜ | 嫌疑面:AHCI DMA PRDT 边界 / fat32_read_sectors 缓冲边界 / DSK .bss 内大缓冲(g_fdata 10MB、ibuf 8MB)相邻越界。写零发生在跳转后、sha256 前;确切写者与范围待断点级排查 | — | + ## 文档体系 | 文档 | 状态 | 说明 |