From: simon Date: Thu, 6 Mar 2003 13:24:02 +0000 (+0000) Subject: Reorganisation of misc.c: Minefield has moved out to winmisc.c, and X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/putty/commitdiff_plain/d0912d1f5b4c65b0be0c3fba2a264a1cfbf96d08 Reorganisation of misc.c: Minefield has moved out to winmisc.c, and so has the Windows dputs() - which has also acquired a Unix counterpart in uxmisc.c. -DDEBUG should now work on Unix. git-svn-id: svn://svn.tartarus.org/sgt/putty@2914 cda61777-01e9-0310-a592-d414129be87e --- diff --git a/misc.c b/misc.c index e4c6d4ac..8edb41a8 100644 --- a/misc.c +++ b/misc.c @@ -266,225 +266,10 @@ void bufchain_fetch(bufchain *ch, void *data, int len) */ #ifdef MINEFIELD -/* - * Minefield - a Windows equivalent for Electric Fence - */ - -#define PAGESIZE 4096 - -/* - * Design: - * - * We start by reserving as much virtual address space as Windows - * will sensibly (or not sensibly) let us have. We flag it all as - * invalid memory. - * - * Any allocation attempt is satisfied by committing one or more - * pages, with an uncommitted page on either side. The returned - * memory region is jammed up against the _end_ of the pages. - * - * Freeing anything causes instantaneous decommitment of the pages - * involved, so stale pointers are caught as soon as possible. - */ - -static int minefield_initialised = 0; -static void *minefield_region = NULL; -static long minefield_size = 0; -static long minefield_npages = 0; -static long minefield_curpos = 0; -static unsigned short *minefield_admin = NULL; -static void *minefield_pages = NULL; - -static void minefield_admin_hide(int hide) -{ - int access = hide ? PAGE_NOACCESS : PAGE_READWRITE; - VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL); -} - -static void minefield_init(void) -{ - int size; - int admin_size; - int i; - - for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) { - minefield_region = VirtualAlloc(NULL, size, - MEM_RESERVE, PAGE_NOACCESS); - if (minefield_region) - break; - } - minefield_size = size; - - /* - * Firstly, allocate a section of that to be the admin block. - * We'll need a two-byte field for each page. - */ - minefield_admin = minefield_region; - minefield_npages = minefield_size / PAGESIZE; - admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1); - minefield_npages = (minefield_size - admin_size) / PAGESIZE; - minefield_pages = (char *) minefield_region + admin_size; - - /* - * Commit the admin region. - */ - VirtualAlloc(minefield_admin, minefield_npages * 2, - MEM_COMMIT, PAGE_READWRITE); - - /* - * Mark all pages as unused (0xFFFF). - */ - for (i = 0; i < minefield_npages; i++) - minefield_admin[i] = 0xFFFF; - - /* - * Hide the admin region. - */ - minefield_admin_hide(1); - - minefield_initialised = 1; -} - -static void minefield_bomb(void) -{ - div(1, *(int *) minefield_pages); -} - -static void *minefield_alloc(int size) -{ - int npages; - int pos, lim, region_end, region_start; - int start; - int i; - - npages = (size + PAGESIZE - 1) / PAGESIZE; - - minefield_admin_hide(0); - - /* - * Search from current position until we find a contiguous - * bunch of npages+2 unused pages. - */ - pos = minefield_curpos; - lim = minefield_npages; - while (1) { - /* Skip over used pages. */ - while (pos < lim && minefield_admin[pos] != 0xFFFF) - pos++; - /* Count unused pages. */ - start = pos; - while (pos < lim && pos - start < npages + 2 && - minefield_admin[pos] == 0xFFFF) - pos++; - if (pos - start == npages + 2) - break; - /* If we've reached the limit, reset the limit or stop. */ - if (pos >= lim) { - if (lim == minefield_npages) { - /* go round and start again at zero */ - lim = minefield_curpos; - pos = 0; - } else { - minefield_admin_hide(1); - return NULL; - } - } - } - - minefield_curpos = pos - 1; - - /* - * We have npages+2 unused pages starting at start. We leave - * the first and last of these alone and use the rest. - */ - region_end = (start + npages + 1) * PAGESIZE; - region_start = region_end - size; - /* FIXME: could align here if we wanted */ - - /* - * Update the admin region. - */ - for (i = start + 2; i < start + npages + 1; i++) - minefield_admin[i] = 0xFFFE; /* used but no region starts here */ - minefield_admin[start + 1] = region_start % PAGESIZE; - - minefield_admin_hide(1); - - VirtualAlloc((char *) minefield_pages + region_start, size, - MEM_COMMIT, PAGE_READWRITE); - return (char *) minefield_pages + region_start; -} - -static void minefield_free(void *ptr) -{ - int region_start, i, j; - - minefield_admin_hide(0); - - region_start = (char *) ptr - (char *) minefield_pages; - i = region_start / PAGESIZE; - if (i < 0 || i >= minefield_npages || - minefield_admin[i] != region_start % PAGESIZE) - minefield_bomb(); - for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) { - minefield_admin[j] = 0xFFFF; - } - - VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT); - - minefield_admin_hide(1); -} - -static int minefield_get_size(void *ptr) -{ - int region_start, i, j; - - minefield_admin_hide(0); - - region_start = (char *) ptr - (char *) minefield_pages; - i = region_start / PAGESIZE; - if (i < 0 || i >= minefield_npages || - minefield_admin[i] != region_start % PAGESIZE) - minefield_bomb(); - for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++); - - minefield_admin_hide(1); - - return j * PAGESIZE - region_start; -} - -static void *minefield_c_malloc(size_t size) -{ - if (!minefield_initialised) - minefield_init(); - return minefield_alloc(size); -} - -static void minefield_c_free(void *p) -{ - if (!minefield_initialised) - minefield_init(); - minefield_free(p); -} - -/* - * realloc _always_ moves the chunk, for rapid detection of code - * that assumes it won't. - */ -static void *minefield_c_realloc(void *p, size_t size) -{ - size_t oldsize; - void *q; - if (!minefield_initialised) - minefield_init(); - q = minefield_alloc(size); - oldsize = minefield_get_size(p); - memcpy(q, p, (oldsize < size ? oldsize : size)); - minefield_free(p); - return q; -} - -#endif /* MINEFIELD */ +void *minefield_c_malloc(size_t size); +void minefield_c_free(void *p); +void *minefield_c_realloc(void *p, size_t size); +#endif #ifdef MALLOC_LOG static FILE *fp = NULL; @@ -591,33 +376,9 @@ void safefree(void *ptr) */ #ifdef DEBUG -static FILE *debug_fp = NULL; -static HANDLE debug_hdl = INVALID_HANDLE_VALUE; -static int debug_got_console = 0; - -static void dputs(char *buf) -{ - DWORD dw; - - if (!debug_got_console) { - if (AllocConsole()) { - debug_got_console = 1; - debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE); - } - } - if (!debug_fp) { - debug_fp = fopen("debug.log", "w"); - } - - if (debug_hdl != INVALID_HANDLE_VALUE) { - WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL); - } - fputs(buf, debug_fp); - fflush(debug_fp); -} - +extern void dputs(char *); /* defined in per-platform *misc.c */ -void dprintf(char *fmt, ...) +void debug_printf(char *fmt, ...) { char *buf; va_list ap; @@ -637,7 +398,7 @@ void debug_memdump(void *buf, int len, int L) char foo[17]; if (L) { int delta; - dprintf("\t%d (0x%x) bytes:\n", len, len); + debug_printf("\t%d (0x%x) bytes:\n", len, len); delta = 15 & (int) p; p -= delta; len += delta; @@ -645,14 +406,14 @@ void debug_memdump(void *buf, int len, int L) for (; 0 < len; p += 16, len -= 16) { dputs(" "); if (L) - dprintf("%p: ", p); + debug_printf("%p: ", p); strcpy(foo, "................"); /* sixteen dots */ for (i = 0; i < 16 && i < len; ++i) { if (&p[i] < (unsigned char *) buf) { dputs(" "); /* 3 spaces */ foo[i] = ' '; } else { - dprintf("%c%02.2x", + debug_printf("%c%02.2x", &p[i] != (unsigned char *) buf && i % 4 ? '.' : ' ', p[i] ); @@ -661,7 +422,7 @@ void debug_memdump(void *buf, int len, int L) } } foo[i] = '\0'; - dprintf("%*s%s\n", (16 - i) * 3 + 2, "", foo); + debug_printf("%*s%s\n", (16 - i) * 3 + 2, "", foo); } } diff --git a/misc.h b/misc.h index aa723629..7d0ee4d5 100644 --- a/misc.h +++ b/misc.h @@ -50,9 +50,9 @@ void bufchain_fetch(bufchain *ch, void *data, int len); */ #ifdef DEBUG -void dprintf(char *fmt, ...); +void debug_printf(char *fmt, ...); void debug_memdump(void *buf, int len, int L); -#define debug(x) (dprintf x) +#define debug(x) (debug_printf x) #define dmemdump(buf,len) debug_memdump (buf, len, 0); #define dmemdumpl(buf,len) debug_memdump (buf, len, 1); #else diff --git a/unix/uxmisc.c b/unix/uxmisc.c index 8239158e..6889bcaf 100644 --- a/unix/uxmisc.c +++ b/unix/uxmisc.c @@ -3,6 +3,7 @@ */ #include +#include #include #include "putty.h" @@ -40,3 +41,19 @@ int filename_is_null(Filename fn) { return !*fn.path; } + +#ifdef DEBUG +static FILE *debug_fp = NULL; + +void dputs(char *buf) +{ + if (!debug_fp) { + debug_fp = fopen("debug.log", "w"); + } + + write(1, buf, strlen(buf)); + + fputs(buf, debug_fp); + fflush(debug_fp); +} +#endif diff --git a/winmisc.c b/winmisc.c index 22663419..2590befe 100644 --- a/winmisc.c +++ b/winmisc.c @@ -35,3 +35,251 @@ int filename_is_null(Filename fn) { return !*fn.path; } + +#ifdef DEBUG +static FILE *debug_fp = NULL; +static HANDLE debug_hdl = INVALID_HANDLE_VALUE; +static int debug_got_console = 0; + +void dputs(char *buf) +{ + DWORD dw; + + if (!debug_got_console) { + if (AllocConsole()) { + debug_got_console = 1; + debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE); + } + } + if (!debug_fp) { + debug_fp = fopen("debug.log", "w"); + } + + if (debug_hdl != INVALID_HANDLE_VALUE) { + WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL); + } + fputs(buf, debug_fp); + fflush(debug_fp); +} +#endif + +#ifdef MINEFIELD +/* + * Minefield - a Windows equivalent for Electric Fence + */ + +#define PAGESIZE 4096 + +/* + * Design: + * + * We start by reserving as much virtual address space as Windows + * will sensibly (or not sensibly) let us have. We flag it all as + * invalid memory. + * + * Any allocation attempt is satisfied by committing one or more + * pages, with an uncommitted page on either side. The returned + * memory region is jammed up against the _end_ of the pages. + * + * Freeing anything causes instantaneous decommitment of the pages + * involved, so stale pointers are caught as soon as possible. + */ + +static int minefield_initialised = 0; +static void *minefield_region = NULL; +static long minefield_size = 0; +static long minefield_npages = 0; +static long minefield_curpos = 0; +static unsigned short *minefield_admin = NULL; +static void *minefield_pages = NULL; + +static void minefield_admin_hide(int hide) +{ + int access = hide ? PAGE_NOACCESS : PAGE_READWRITE; + VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL); +} + +static void minefield_init(void) +{ + int size; + int admin_size; + int i; + + for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) { + minefield_region = VirtualAlloc(NULL, size, + MEM_RESERVE, PAGE_NOACCESS); + if (minefield_region) + break; + } + minefield_size = size; + + /* + * Firstly, allocate a section of that to be the admin block. + * We'll need a two-byte field for each page. + */ + minefield_admin = minefield_region; + minefield_npages = minefield_size / PAGESIZE; + admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1); + minefield_npages = (minefield_size - admin_size) / PAGESIZE; + minefield_pages = (char *) minefield_region + admin_size; + + /* + * Commit the admin region. + */ + VirtualAlloc(minefield_admin, minefield_npages * 2, + MEM_COMMIT, PAGE_READWRITE); + + /* + * Mark all pages as unused (0xFFFF). + */ + for (i = 0; i < minefield_npages; i++) + minefield_admin[i] = 0xFFFF; + + /* + * Hide the admin region. + */ + minefield_admin_hide(1); + + minefield_initialised = 1; +} + +static void minefield_bomb(void) +{ + div(1, *(int *) minefield_pages); +} + +static void *minefield_alloc(int size) +{ + int npages; + int pos, lim, region_end, region_start; + int start; + int i; + + npages = (size + PAGESIZE - 1) / PAGESIZE; + + minefield_admin_hide(0); + + /* + * Search from current position until we find a contiguous + * bunch of npages+2 unused pages. + */ + pos = minefield_curpos; + lim = minefield_npages; + while (1) { + /* Skip over used pages. */ + while (pos < lim && minefield_admin[pos] != 0xFFFF) + pos++; + /* Count unused pages. */ + start = pos; + while (pos < lim && pos - start < npages + 2 && + minefield_admin[pos] == 0xFFFF) + pos++; + if (pos - start == npages + 2) + break; + /* If we've reached the limit, reset the limit or stop. */ + if (pos >= lim) { + if (lim == minefield_npages) { + /* go round and start again at zero */ + lim = minefield_curpos; + pos = 0; + } else { + minefield_admin_hide(1); + return NULL; + } + } + } + + minefield_curpos = pos - 1; + + /* + * We have npages+2 unused pages starting at start. We leave + * the first and last of these alone and use the rest. + */ + region_end = (start + npages + 1) * PAGESIZE; + region_start = region_end - size; + /* FIXME: could align here if we wanted */ + + /* + * Update the admin region. + */ + for (i = start + 2; i < start + npages + 1; i++) + minefield_admin[i] = 0xFFFE; /* used but no region starts here */ + minefield_admin[start + 1] = region_start % PAGESIZE; + + minefield_admin_hide(1); + + VirtualAlloc((char *) minefield_pages + region_start, size, + MEM_COMMIT, PAGE_READWRITE); + return (char *) minefield_pages + region_start; +} + +static void minefield_free(void *ptr) +{ + int region_start, i, j; + + minefield_admin_hide(0); + + region_start = (char *) ptr - (char *) minefield_pages; + i = region_start / PAGESIZE; + if (i < 0 || i >= minefield_npages || + minefield_admin[i] != region_start % PAGESIZE) + minefield_bomb(); + for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) { + minefield_admin[j] = 0xFFFF; + } + + VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT); + + minefield_admin_hide(1); +} + +static int minefield_get_size(void *ptr) +{ + int region_start, i, j; + + minefield_admin_hide(0); + + region_start = (char *) ptr - (char *) minefield_pages; + i = region_start / PAGESIZE; + if (i < 0 || i >= minefield_npages || + minefield_admin[i] != region_start % PAGESIZE) + minefield_bomb(); + for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++); + + minefield_admin_hide(1); + + return j * PAGESIZE - region_start; +} + +void *minefield_c_malloc(size_t size) +{ + if (!minefield_initialised) + minefield_init(); + return minefield_alloc(size); +} + +void minefield_c_free(void *p) +{ + if (!minefield_initialised) + minefield_init(); + minefield_free(p); +} + +/* + * realloc _always_ moves the chunk, for rapid detection of code + * that assumes it won't. + */ +void *minefield_c_realloc(void *p, size_t size) +{ + size_t oldsize; + void *q; + if (!minefield_initialised) + minefield_init(); + q = minefield_alloc(size); + oldsize = minefield_get_size(p); + memcpy(q, p, (oldsize < size ? oldsize : size)); + minefield_free(p); + return q; +} + +#endif /* MINEFIELD */