From 9343e9338ddf1015a63a95e4e78bfe659a557b76 Mon Sep 17 00:00:00 2001 From: Joshua Wise Date: Tue, 11 Nov 2008 19:36:28 -0500 Subject: [PATCH] Stack trace better if I take my stack trace better pill. --- aseg-paging/pagingstub.c | 55 +++++++++++++++++++++++++++++++--------- include/minilib.h | 1 + include/paging.h | 2 ++ lib/minilib.c | 9 +++++++ net/http/fs.c | 52 +++++++++++++++++++++++++++++++++++++ net/http/fsdata.c | 7 +++-- 6 files changed, 112 insertions(+), 14 deletions(-) diff --git a/aseg-paging/pagingstub.c b/aseg-paging/pagingstub.c index 161dc1f..7d430b9 100644 --- a/aseg-paging/pagingstub.c +++ b/aseg-paging/pagingstub.c @@ -40,6 +40,8 @@ static unsigned long *pd; extern int _bss, _bssend, _end; +static unsigned long curmapped = 0xFFFFFFFF; + unsigned long v2p(void *virt) { unsigned long _virt = (unsigned long)virt; @@ -51,6 +53,11 @@ unsigned long v2p(void *virt) return _virt; if (_virt >= 0x200000 && _virt < 0x300000) return _virt - 0x200000 + /* XXX */ 0x1FF82000; + if (_virt >= 0x1F0000 && _virt < 0x1F2000) + return _virt - 0x1F0000 + 0x1FF80000; + if ((_virt & ~0xFFF) == 0x4000) + return _virt - 0x4000 + curmapped; + outputf("WARNING: v2p(%08x)", _virt); return 0xFFFFFFFF; } @@ -62,14 +69,21 @@ void *p2v(unsigned long phys) if (phys >= 0xA0000 && phys < 0xC0000) return (void*)phys; - if (phys >= 0x1FF80000 && phys < 0x20000000) + if (phys >= 0x1FF82000 && phys < 0x20000000) return (void*)(phys - 0x1FF82000 + 0x200000); - outputf("WARNING: p2v(%08x)", phys); - return (void *)0xFFFFFFFF; + if (phys >= 0x1FF80000 && phys < 0x1FF82000) + return (void*)(phys - 0x1FF80000 + 0x1F0000); + + if ((phys & ~0xFFF) != curmapped) /* If it's not mapped, map it in. */ + { + curmapped = phys & ~0xFFF; + addmap(0x4000, curmapped); + asm volatile("invlpg 0x4000"); + } + return (void*)(0x4000 + (phys & 0xFFF)); } - -inline int pt_addmap(unsigned long *pd, unsigned long vaddr, unsigned long paddr) +int addmap(unsigned long vaddr, unsigned long paddr) { unsigned long pde = ((unsigned long *)p2v((unsigned long)pd))[PDE_FOR(vaddr)]; unsigned long *pt; @@ -83,13 +97,28 @@ inline int pt_addmap(unsigned long *pd, unsigned long vaddr, unsigned long paddr return 0; } -static void * pt_setup(int tseg_start, int tseg_size) { +void *demap(unsigned long client_pd, unsigned long vaddr) +{ + unsigned long pde = ((unsigned long *)p2v(client_pd))[PDE_FOR(vaddr)]; + unsigned long pte; + + if (!(pde & PTE_PRESENT)) + return (void*)0x0; + pte = ((unsigned long *)p2v(ADDR_12_MASK(pde)))[PTE_FOR(vaddr)]; + if (!(pte & PTE_PRESENT)) + return (void*)0x0; + return p2v((pte & ~0xFFF) + (vaddr & 0xFFF)); +} + +static void pt_setup(int tseg_start, int tseg_size) { int i; /* The page directory and page table live at TSEG and TSEG + 0x1000, * respectively. */ unsigned long *pagedirectory = (unsigned long *) tseg_start; unsigned long *pagetable = (unsigned long *) (tseg_start + 0x1000); + + pd = pagedirectory; /* Clear out the page directory except for one entry pointing to the * page table, and clear the page table entirely. */ @@ -102,18 +131,20 @@ static void * pt_setup(int tseg_start, int tseg_size) { /* Map 0x0A0000:0x0BFFFF to itself. */ for (i = 0; i < 32; i++) - pt_addmap(pagedirectory, 0xA0000 + i * 0x1000, 0xA0000 + i * 0x1000); + addmap(0xA0000 + i * 0x1000, 0xA0000 + i * 0x1000); - /* Map 0x200000:0x300000 to TSEG */ + /* Map 0x200000:0x300000 to TSEG data */ for (i = 0; i < 256; i++) - pt_addmap(pagedirectory, 0x200000 + i * 0x1000, tseg_start + 0x2000 + i * 0x1000); + addmap(0x200000 + i * 0x1000, tseg_start + (i + 2) * 0x1000); /* Map 0x300000:0x400000 to 0x200000, so we can copy our code out of * RAM the first time around */ for (i = 0; i < 256; i++) - pt_addmap(pagedirectory, 0x300000 + i * 0x1000, 0x200000 + i * 0x1000); + addmap(0x300000 + i * 0x1000, 0x200000 + i * 0x1000); - return pagedirectory; + /* Map 0x1F0000:0x1F2000 to TSEG paging info */ + for (i = 0; i < 2; i++) + addmap(0x1F0000 + i * 0x1000, tseg_start + i * 0x1000); } void c_entry(void) @@ -122,7 +153,7 @@ void c_entry(void) outb(0x80, 0x01); if (!initialized) - pd = pt_setup(0x1FF80000, 0x80000); + pt_setup(0x1FF80000, 0x80000); outb(0x80, 0x02); /* Enable paging. */ diff --git a/include/minilib.h b/include/minilib.h index 7d66efb..d743d5b 100644 --- a/include/minilib.h +++ b/include/minilib.h @@ -10,6 +10,7 @@ extern int memcmp(const char *a2, const char *a1, int bytes); extern int strcmp(const char *a2, const char *a1); extern int strncmp(const char *a2, const char *a1, int n); extern int strlen(const char *c); +extern void strcat(char *dest, char *src); extern void strcpy(char *a2, const char *a1); extern void puts(const char *c); extern void tohex(char *s, unsigned long l); diff --git a/include/paging.h b/include/paging.h index fb74a0d..90c44e9 100644 --- a/include/paging.h +++ b/include/paging.h @@ -3,5 +3,7 @@ extern unsigned long v2p(void *virt); extern void *p2v(unsigned long phys); +extern int addmap(unsigned long vaddr, unsigned long paddr); +extern void *demap(unsigned long _pd, unsigned long vaddr); #endif diff --git a/lib/minilib.c b/lib/minilib.c index e90f7af..664a0b4 100644 --- a/lib/minilib.c +++ b/lib/minilib.c @@ -75,6 +75,15 @@ void strcpy(char *a2, const char *a1) } while (*(a1++)); } +void strcat(char *dest, char *src) +{ + while (*dest) + dest++; + while (*src) + *(dest++) = *(src++); + *(dest++) = *(src++); +} + void puts(const char *c) { putbytes(c, strlen(c)); diff --git a/net/http/fs.c b/net/http/fs.c index 54c5bd9..cb7a226 100644 --- a/net/http/fs.c +++ b/net/http/fs.c @@ -34,6 +34,9 @@ #include "fsdata.h" #include "fsdata.c" #include +#include +#include +#include /*-----------------------------------------------------------------------------------*/ @@ -67,6 +70,50 @@ void handle_regs(struct fs_file *file) file->len = strlen(buf)-1; } +void handle_backtrace(struct fs_file *file) +{ + static unsigned char buf[2048]; + static unsigned char buf2[64]; + int i = 10; + unsigned long *pebp, *peip; + unsigned long ebp; + unsigned long cr3; + + strcpy(buf, "Backtrace
");
+  ebp = *(unsigned long *)0xAFFE4;
+  cr3 = *(unsigned long *)0xAFFF8;
+  
+  sprintf(buf2, "0x%08x, from\n", *(unsigned long*)0xAFFF0);
+  strcat(buf, buf2);
+  
+  /* I never thought I'd do this again. */
+  while ((peip = demap(cr3, ebp+4)) != 0x0 && i--)
+  {
+    sprintf(buf2, "0x%08x, from\n", *peip);
+    strcat(buf, buf2);
+    pebp = demap(cr3, ebp);
+    if (!pebp)
+    {
+      strcat(buf, "<unreadable %ebp>\n");
+      break;
+    }
+    if (ebp >= *pebp && *pebp)
+    {
+      strcat(buf, "<recursive %ebp>\n");
+      break;
+    }
+    ebp = *pebp;
+  }
+  if (i == -1)
+    strcat(buf, "...\n");
+  else
+    strcat(buf, "<root>");
+  strcat(buf, "
"); + + file->data = buf; + file->len = strlen(buf)-1; +} + void handle_reboot(struct fs_file *file) { outb(0xCF9, 0x4); @@ -87,6 +134,11 @@ fs_open(const char *name, struct fs_file *file) handle_regs(file); return 1; } + if (!strcmp(name, "/backtrace.html")) + { + handle_backtrace(file); + return 1; + } if (!strcmp(name, "/reboot")) { handle_reboot(file); diff --git a/net/http/fsdata.c b/net/http/fsdata.c index 57180f3..70337a8 100644 --- a/net/http/fsdata.c +++ b/net/http/fsdata.c @@ -5,8 +5,11 @@ static const unsigned char data_404_html[] = static const unsigned char data_index_html[] = "NetWatch" - "

NetWatch

" - ""; + "

NetWatch

" + "
" + "" + "
" + ""; const struct fsdata_file file_404_html[] = {{NULL, "/404.html", data_404_html, sizeof(data_404_html)}}; const struct fsdata_file file_index_html[] = {{file_404_html, "/index.html", data_index_html, sizeof(data_index_html)}}; -- 2.39.2