Commit 31aa2b6f authored by Tor Didriksen's avatar Tor Didriksen

Bug#11761576 54082: HANDLE_SEGFAULT MAKES USE OF UNSAFE FUNCTIONS

handle_segfault is the signal handler code of mysqld.  however, it makes
calls to potentially unsafe functions localtime_r, fprintf, fflush.
parent cfef24eb
/*
Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
/* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
......@@ -12,8 +11,7 @@
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
#ifndef _my_stacktrace_h_
#define _my_stacktrace_h_
......@@ -63,6 +61,69 @@ void my_set_exception_pointers(EXCEPTION_POINTERS *ep);
void my_write_core(int sig);
#endif
/**
Async-signal-safe utility functions used by signal handler routines.
Declared here in order to unit-test them.
These are not general-purpose, but tailored to the signal handling routines.
*/
/**
Converts a longlong value to string.
@param base 10 for decimal, 16 for hex values (0..9a..f)
@param val The value to convert
@param buf Assumed to point to the *end* of the buffer.
@returns Pointer to the first character of the converted string.
Negative values:
for base-10 the return string will be prepended with '-'
for base-16 the return string will contain 16 characters
Implemented with simplicity, and async-signal-safety in mind.
*/
char *my_safe_itoa(int base, longlong val, char *buf);
/**
Converts a ulonglong value to string.
@param base 10 for decimal, 16 for hex values (0..9a..f)
@param val The value to convert
@param buf Assumed to point to the *end* of the buffer.
@returns Pointer to the first character of the converted string.
Implemented with simplicity, and async-signal-safety in mind.
*/
char *my_safe_utoa(int base, ulonglong val, char *buf);
/**
A (very) limited version of snprintf.
@param to Destination buffer.
@param n Size of destination buffer.
@param fmt printf() style format string.
@returns Number of bytes written, including terminating '\0'
Supports 'd' 'i' 'u' 'x' 'p' 's' conversion.
Supports 'l' and 'll' modifiers for integral types.
Does not support any width/precision.
Implemented with simplicity, and async-signal-safety in mind.
*/
size_t my_safe_snprintf(char* to, size_t n, const char* fmt, ...)
ATTRIBUTE_FORMAT(printf, 3, 4);
/**
A (very) limited version of snprintf, which writes the result to STDERR.
@sa my_safe_snprintf
Implemented with simplicity, and async-signal-safety in mind.
@note Has an internal buffer capacity of 512 bytes,
which should suffice for our signal handling routines.
*/
size_t my_safe_printf_stderr(const char* fmt, ...)
ATTRIBUTE_FORMAT(printf, 1, 2);
/**
Writes up to count bytes from buffer to STDERR.
Implemented with simplicity, and async-signal-safety in mind.
@param buf Buffer containing data to be written.
@param count Number of bytes to write.
@returns Number of bytes written.
*/
size_t my_write_stderr(const void *buf, size_t count);
C_MODE_END
#endif /* _my_stacktrace_h_ */
......@@ -109,6 +109,7 @@ SET(LIBMYSQLD_SOURCES emb_qcache.cc libmysqld.c lib_sql.cc
../sql/password.c ../sql/discover.cc ../sql/derror.cc
../sql/field.cc ../sql/field_conv.cc
../sql/filesort.cc ../sql/gstream.cc ../sql/ha_partition.cc
../sql/signal_handler.cc
../sql/handler.cc ../sql/hash_filo.cc ../sql/hostname.cc
../sql/init.cc ../sql/item_buff.cc ../sql/item_cmpfunc.cc
../sql/item.cc ../sql/item_create.cc ../sql/item_func.cc
......
/*
Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
/* Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
......@@ -12,8 +11,8 @@
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/* Workaround for Bug#32082: VOID redefinition on Win results in compile errors*/
#define DONT_DEFINE_VOID 1
......@@ -57,10 +56,11 @@ void my_init_stacktrace()
static void print_buffer(char *buffer, size_t count)
{
const char s[]= " ";
for (; count && *buffer; --count)
{
int c= (int) *buffer++;
fputc(isprint(c) ? c : ' ', stderr);
my_write_stderr(isprint(*buffer) ? buffer : s, 1);
++buffer;
}
}
......@@ -124,10 +124,10 @@ static int safe_print_str(const char *addr, int max_len)
/* Output a new line if something was printed. */
if (total != (size_t) max_len)
fputc('\n', stderr);
my_safe_printf_stderr("%s", "\n");
if (nbytes == -1)
fprintf(stderr, "Can't read from address %p: %m.\n", addr);
my_safe_printf_stderr("Can't read from address %p\n", addr);
close(fd);
......@@ -149,13 +149,13 @@ void my_safe_print_str(const char* val, int max_len)
if (!PTR_SANE(val))
{
fprintf(stderr, "is an invalid pointer\n");
my_safe_printf_stderr("%s", "is an invalid pointer\n");
return;
}
for (; max_len && PTR_SANE(val) && *val; --max_len)
fputc(*val++, stderr);
fputc('\n', stderr);
my_write_stderr((val++), 1);
my_safe_printf_stderr("%s", "\n");
}
#if defined(HAVE_PRINTSTACK)
......@@ -167,14 +167,15 @@ void my_print_stacktrace(uchar* stack_bottom __attribute__((unused)),
ulong thread_stack __attribute__((unused)))
{
if (printstack(fileno(stderr)) == -1)
fprintf(stderr, "Error when traversing the stack, stack appears corrupt.\n");
my_safe_printf_stderr("%s",
"Error when traversing the stack, stack appears corrupt.\n");
else
fprintf(stderr,
"Please read "
"http://dev.mysql.com/doc/refman/5.1/en/resolve-stack-dump.html\n"
"and follow instructions on how to resolve the stack trace.\n"
"Resolved stack trace is much more helpful in diagnosing the\n"
"problem, so please do resolve it\n");
my_safe_printf_stderr("%s"
"Please read "
"http://dev.mysql.com/doc/refman/5.1/en/resolve-stack-dump.html\n"
"and follow instructions on how to resolve the stack trace.\n"
"Resolved stack trace is much more helpful in diagnosing the\n"
"problem, so please do resolve it\n");
}
#elif HAVE_BACKTRACE && (HAVE_BACKTRACE_SYMBOLS || HAVE_BACKTRACE_SYMBOLS_FD)
......@@ -212,9 +213,9 @@ static void my_demangle_symbols(char **addrs, int n)
}
if (demangled)
fprintf(stderr, "%s(%s+%s\n", addrs[i], demangled, end);
my_safe_printf_stderr("%s(%s+%s\n", addrs[i], demangled, end);
else
fprintf(stderr, "%s\n", addrs[i]);
my_safe_printf_stderr("%s\n", addrs[i]);
}
}
......@@ -225,8 +226,8 @@ void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack)
void *addrs[128];
char **strings= NULL;
int n = backtrace(addrs, array_elements(addrs));
fprintf(stderr, "stack_bottom = %p thread_stack 0x%lx\n",
stack_bottom, thread_stack);
my_safe_printf_stderr("stack_bottom = %p thread_stack 0x%lx\n",
stack_bottom, thread_stack);
#if BACKTRACE_DEMANGLE
if ((strings= backtrace_symbols(addrs, n)))
{
......@@ -319,8 +320,9 @@ void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack)
#endif
if (!fp)
{
fprintf(stderr, "frame pointer is NULL, did you compile with\n\
-fomit-frame-pointer? Aborting backtrace!\n");
my_safe_printf_stderr("%s",
"frame pointer is NULL, did you compile with\n"
"-fomit-frame-pointer? Aborting backtrace!\n");
return;
}
......@@ -328,24 +330,28 @@ void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack)
{
ulong tmp= min(0x10000,thread_stack);
/* Assume that the stack starts at the previous even 65K */
stack_bottom= (uchar*) (((ulong) &fp + tmp) &
~(ulong) 0xFFFF);
fprintf(stderr, "Cannot determine thread, fp=%p, backtrace may not be correct.\n", fp);
stack_bottom= (uchar*) (((ulong) &fp + tmp) & ~(ulong) 0xFFFF);
my_safe_printf_stderr("Cannot determine thread, fp=%p, "
"backtrace may not be correct.\n", fp);
}
if (fp > (uchar**) stack_bottom ||
fp < (uchar**) stack_bottom - thread_stack)
{
fprintf(stderr, "Bogus stack limit or frame pointer,\
fp=%p, stack_bottom=%p, thread_stack=%ld, aborting backtrace.\n",
fp, stack_bottom, thread_stack);
my_safe_printf_stderr("Bogus stack limit or frame pointer, "
"fp=%p, stack_bottom=%p, thread_stack=%ld, "
"aborting backtrace.\n",
fp, stack_bottom, thread_stack);
return;
}
fprintf(stderr, "Stack range sanity check OK, backtrace follows:\n");
my_safe_printf_stderr("%s",
"Stack range sanity check OK, backtrace follows:\n");
#if defined(__alpha__) && defined(__GNUC__)
fprintf(stderr, "Warning: Alpha stacks are difficult -\
will be taking some wild guesses, stack trace may be incorrect or \
terminate abruptly\n");
my_safe_printf_stderr("%s",
"Warning: Alpha stacks are difficult -"
"will be taking some wild guesses, stack trace may be incorrect or "
"terminate abruptly\n");
/* On Alpha, we need to get pc */
__asm __volatile__ ("bsr %0, do_next; do_next: "
:"=r"(pc)
......@@ -359,8 +365,9 @@ void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack)
{
#if defined(__i386__) || defined(__x86_64__)
uchar** new_fp = (uchar**)*fp;
fprintf(stderr, "%p\n", frame_count == sigreturn_frame_count ?
*(fp + SIGRETURN_FRAME_OFFSET) : *(fp + 1));
my_safe_printf_stderr("%p\n",
frame_count == sigreturn_frame_count ?
*(fp + SIGRETURN_FRAME_OFFSET) : *(fp + 1));
#endif /* defined(__386__) || defined(__x86_64__) */
#if defined(__alpha__) && defined(__GNUC__)
......@@ -374,38 +381,40 @@ void my_print_stacktrace(uchar* stack_bottom, ulong thread_stack)
{
pc = find_prev_pc(pc, fp);
if (pc)
fprintf(stderr, "%p\n", pc);
my_safe_printf_stderr("%p\n", pc);
else
{
fprintf(stderr, "Not smart enough to deal with the rest\
of this stack\n");
my_safe_printf_stderr("%s",
"Not smart enough to deal with the rest of this stack\n");
goto end;
}
}
else
{
fprintf(stderr, "Not smart enough to deal with the rest of this stack\n");
my_safe_printf_stderr("%s",
"Not smart enough to deal with the rest of this stack\n");
goto end;
}
#endif /* defined(__alpha__) && defined(__GNUC__) */
if (new_fp <= fp )
{
fprintf(stderr, "New value of fp=%p failed sanity check,\
terminating stack trace!\n", new_fp);
my_safe_printf_stderr("New value of fp=%p failed sanity check, "
"terminating stack trace!\n", new_fp);
goto end;
}
fp = new_fp;
++frame_count;
}
fprintf(stderr, "Stack trace seems successful - bottom reached\n");
my_safe_printf_stderr("%s",
"Stack trace seems successful - bottom reached\n");
end:
fprintf(stderr,
"Please read http://dev.mysql.com/doc/refman/5.1/en/resolve-stack-dump.html\n"
"and follow instructions on how to resolve the stack trace.\n"
"Resolved stack trace is much more helpful in diagnosing the\n"
"problem, so please do resolve it\n");
my_safe_printf_stderr("%s",
"Please read "
"http://dev.mysql.com/doc/refman/5.1/en/resolve-stack-dump.html\n"
"and follow instructions on how to resolve the stack trace.\n"
"Resolved stack trace is much more helpful in diagnosing the\n"
"problem, so please do resolve it\n");
}
#endif /* TARGET_OS_LINUX */
#endif /* HAVE_STACKTRACE */
......@@ -670,7 +679,7 @@ void my_print_stacktrace(uchar* unused1, ulong unused2)
&(package.sym));
have_source= pSymGetLineFromAddr64(hProcess, addr, &line_offset, &line);
fprintf(stderr, "%p ", addr);
my_safe_printf_stderr("%p ", addr);
if(have_module)
{
char *base_image_name= strrchr(module.ImageName, '\\');
......@@ -678,12 +687,13 @@ void my_print_stacktrace(uchar* unused1, ulong unused2)
base_image_name++;
else
base_image_name= module.ImageName;
fprintf(stderr, "%s!", base_image_name);
my_safe_printf_stderr("%s!", base_image_name);
}
if(have_symbol)
fprintf(stderr, "%s()", package.sym.Name);
my_safe_printf_stderr("%s()", package.sym.Name);
else if(have_module)
fprintf(stderr, "???");
my_safe_printf_stderr("%s", "???");
if(have_source)
{
......@@ -692,11 +702,11 @@ void my_print_stacktrace(uchar* unused1, ulong unused2)
base_file_name++;
else
base_file_name= line.FileName;
fprintf(stderr,"[%s:%u]", base_file_name, line.LineNumber);
my_safe_printf_stderr("[%s:%u]",
base_file_name, line.LineNumber);
}
fprintf(stderr, "\n");
my_safe_printf_stderr("%s", "\n");
}
fflush(stderr);
}
......@@ -733,22 +743,22 @@ void my_write_core(int unused)
if(pMiniDumpWriteDump(GetCurrentProcess(), GetCurrentProcessId(),
hFile, MiniDumpNormal, &info, 0, 0))
{
fprintf(stderr, "Minidump written to %s\n",
_fullpath(path, dump_fname, sizeof(path)) ? path : dump_fname);
my_safe_printf_stderr("Minidump written to %s\n",
_fullpath(path, dump_fname, sizeof(path)) ?
path : dump_fname);
}
else
{
fprintf(stderr,"MiniDumpWriteDump() failed, last error %u\n",
GetLastError());
my_safe_printf_stderr("MiniDumpWriteDump() failed, last error %u\n",
(uint) GetLastError());
}
CloseHandle(hFile);
}
else
{
fprintf(stderr, "CreateFile(%s) failed, last error %u\n", dump_fname,
GetLastError());
my_safe_printf_stderr("CreateFile(%s) failed, last error %u\n",
dump_fname, (uint) GetLastError());
}
fflush(stderr);
}
......@@ -756,11 +766,212 @@ void my_safe_print_str(const char *val, int len)
{
__try
{
fprintf(stderr,"=%.*s\n", len, val);
my_write_stderr(val, len);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
fprintf(stderr,"is an invalid string pointer\n");
my_safe_printf_stderr("%s", "is an invalid string pointer\n");
}
}
#endif /*__WIN__*/
#ifdef __WIN__
size_t my_write_stderr(const void *buf, size_t count)
{
DWORD bytes_written;
SetFilePointer(GetStdHandle(STD_ERROR_HANDLE), 0, NULL, FILE_END);
WriteFile(GetStdHandle(STD_ERROR_HANDLE), buf, count, &bytes_written, NULL);
return bytes_written;
}
#else
size_t my_write_stderr(const void *buf, size_t count)
{
return (size_t) write(STDERR_FILENO, buf, count);
}
#endif
static const char digits[]= "0123456789abcdef";
char *my_safe_utoa(int base, ulonglong val, char *buf)
{
*buf--= 0;
do {
*buf--= digits[val % base];
} while ((val /= base) != 0);
return buf + 1;
}
char *my_safe_itoa(int base, longlong val, char *buf)
{
char *orig_buf= buf;
const my_bool is_neg= (val < 0);
*buf--= 0;
if (is_neg)
val= -val;
if (is_neg && base == 16)
{
int ix;
val-= 1;
for (ix= 0; ix < 16; ++ix)
buf[-ix]= '0';
}
do {
*buf--= digits[val % base];
} while ((val /= base) != 0);
if (is_neg && base == 10)
*buf--= '-';
if (is_neg && base == 16)
{
int ix;
buf= orig_buf - 1;
for (ix= 0; ix < 16; ++ix, --buf)
{
switch (*buf)
{
case '0': *buf= 'f'; break;
case '1': *buf= 'e'; break;
case '2': *buf= 'd'; break;
case '3': *buf= 'c'; break;
case '4': *buf= 'b'; break;
case '5': *buf= 'a'; break;
case '6': *buf= '9'; break;
case '7': *buf= '8'; break;
case '8': *buf= '7'; break;
case '9': *buf= '6'; break;
case 'a': *buf= '5'; break;
case 'b': *buf= '4'; break;
case 'c': *buf= '3'; break;
case 'd': *buf= '2'; break;
case 'e': *buf= '1'; break;
case 'f': *buf= '0'; break;
}
}
}
return buf+1;
}
static const char *check_longlong(const char *fmt, my_bool *have_longlong)
{
*have_longlong= FALSE;
if (*fmt == 'l')
{
fmt++;
if (*fmt != 'l')
*have_longlong= (sizeof(long) == sizeof(longlong));
else
{
fmt++;
*have_longlong= TRUE;
}
}
return fmt;
}
static size_t my_safe_vsnprintf(char *to, size_t size,
const char* format, va_list ap)
{
char *start= to;
char *end= start + size - 1;
for (; *format; ++format)
{
my_bool have_longlong = FALSE;
if (*format != '%')
{
if (to == end) /* end of buffer */
break;
*to++= *format; /* copy ordinary char */
continue;
}
++format; /* skip '%' */
format= check_longlong(format, &have_longlong);
switch (*format)
{
case 'd':
case 'i':
case 'u':
case 'x':
case 'p':
{
longlong ival= 0;
ulonglong uval = 0;
if (*format == 'p')
have_longlong= (sizeof(void *) == sizeof(longlong));
if (have_longlong)
{
if (*format == 'u')
uval= va_arg(ap, ulonglong);
else
ival= va_arg(ap, longlong);
}
else
{
if (*format == 'u')
uval= va_arg(ap, unsigned int);
else
ival= va_arg(ap, int);
}
{
char buff[22];
const int base= (*format == 'x' || *format == 'p') ? 16 : 10;
char *val_as_str= (*format == 'u') ?
my_safe_utoa(base, uval, &buff[sizeof(buff)-1]) :
my_safe_itoa(base, ival, &buff[sizeof(buff)-1]);
/* Strip off "ffffffff" if we have 'x' format without 'll' */
if (*format == 'x' && !have_longlong && ival < 0)
val_as_str+= 8;
while (*val_as_str && to < end)
*to++= *val_as_str++;
continue;
}
}
case 's':
{
const char *val= va_arg(ap, char*);
if (!val)
val= "(null)";
while (*val && to < end)
*to++= *val++;
continue;
}
}
}
*to= 0;
return to - start;
}
size_t my_safe_snprintf(char* to, size_t n, const char* fmt, ...)
{
size_t result;
va_list args;
va_start(args,fmt);
result= my_safe_vsnprintf(to, n, fmt, args);
va_end(args);
return result;
}
size_t my_safe_printf_stderr(const char* fmt, ...)
{
char to[512];
size_t result;
va_list args;
va_start(args,fmt);
result= my_safe_vsnprintf(to, sizeof(to), fmt, args);
va_end(args);
my_write_stderr(to, result);
return result;
}
......@@ -65,6 +65,7 @@ SET (SQL_SOURCE
sql_list.cc sql_load.cc sql_manager.cc sql_map.cc sql_parse.cc
sql_partition.cc sql_plugin.cc sql_prepare.cc sql_rename.cc
debug_sync.cc debug_sync.h
signal_handler.cc
sql_repl.cc sql_select.cc sql_show.cc sql_state.c sql_string.cc
sql_table.cc sql_test.cc sql_trigger.cc sql_udf.cc sql_union.cc
sql_update.cc sql_view.cc strfunc.cc table.cc thr_malloc.cc
......@@ -113,7 +114,7 @@ IF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)
ADD_CUSTOM_COMMAND(TARGET mysqld PRE_LINK
COMMAND cscript ARGS //nologo ${PROJECT_SOURCE_DIR}/win/create_def_file.js
${PLATFORM} ${LIB_LOCATIONS} > mysqld.def
WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/sql)
WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
ENDIF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)
ADD_DEPENDENCIES(sql GenError)
......
......@@ -103,6 +103,7 @@ mysqld_SOURCES = sql_lex.cc sql_handler.cc sql_partition.cc \
records.cc filesort.cc handler.cc \
ha_partition.cc \
debug_sync.cc \
signal_handler.cc \
sql_db.cc sql_table.cc sql_rename.cc sql_crypt.cc \
sql_load.cc mf_iocache.cc field_conv.cc sql_show.cc \
sql_udf.cc sql_analyse.cc sql_analyse.h sql_cache.cc \
......
......@@ -122,13 +122,6 @@ extern "C" { // Because of SCO 3.2V4.2
#include <sys/mman.h>
#endif
#ifdef __WIN__
#include <crtdbg.h>
#define SIGNAL_FMT "exception 0x%x"
#else
#define SIGNAL_FMT "signal %d"
#endif
#ifdef __NETWARE__
#define zVOLSTATE_ACTIVE 6
#define zVOLSTATE_DEACTIVE 2
......@@ -269,7 +262,7 @@ inline void setup_fpu()
extern "C" int gethostname(char *name, int namelen);
#endif
extern "C" sig_handler handle_segfault(int sig);
extern "C" sig_handler handle_fatal_signal(int sig);
#if defined(__linux__)
#define ENABLE_TEMP_POOL 1
......@@ -415,6 +408,10 @@ TYPELIB log_output_typelib= {array_elements(log_output_names)-1,"",
/* static variables */
#ifdef HAVE_NPTL
volatile sig_atomic_t ld_assume_kernel_is_set= 0;
#endif
/* the default log output is log tables */
static bool lower_case_table_names_used= 0;
static bool max_long_data_size_used= false;
......@@ -424,7 +421,7 @@ static my_bool opt_debugging= 0, opt_external_locking= 0, opt_console= 0;
static my_bool opt_short_log_format= 0;
static uint kill_cached_threads, wake_thread;
static ulong killed_threads, thread_created;
static ulong max_used_connections;
ulong max_used_connections;
static ulong my_bind_addr; /**< the address we bind to */
static volatile ulong cached_thread_count= 0;
static const char *sql_mode_str= "OFF";
......@@ -553,7 +550,7 @@ TYPELIB binlog_format_typelib=
ulong opt_binlog_format_id= (ulong) BINLOG_FORMAT_UNSPEC;
const char *opt_binlog_format= binlog_format_names[opt_binlog_format_id];
#ifdef HAVE_INITGROUPS
static bool calling_initgroups= FALSE; /**< Used in SIGSEGV handler. */
volatile sig_atomic_t calling_initgroups= 0; /**< Used in SIGSEGV handler. */
#endif
uint mysqld_port, test_flags, select_errors, dropping_tables, ha_open_options;
uint mysqld_port_timeout;
......@@ -727,7 +724,7 @@ char *opt_logname, *opt_slow_logname;
/* Static variables */
static bool kill_in_progress, segfaulted;
static volatile sig_atomic_t kill_in_progress;
#ifdef HAVE_STACK_TRACE_ON_SEGV
static my_bool opt_do_pstack;
#endif /* HAVE_STACK_TRACE_ON_SEGV */
......@@ -1616,9 +1613,9 @@ static void set_user(const char *user, struct passwd *user_info_arg)
calling_initgroups as a flag to the SIGSEGV handler that is then used to
output a specific message to help the user resolve this problem.
*/
calling_initgroups= TRUE;
calling_initgroups= 1;
initgroups((char*) user, user_info_arg->pw_gid);
calling_initgroups= FALSE;
calling_initgroups= 0;
#endif
if (setgid(user_info_arg->pw_gid) == -1)
{
......@@ -2170,7 +2167,7 @@ LONG WINAPI my_unhandler_exception_filter(EXCEPTION_POINTERS *ex_pointers)
__try
{
my_set_exception_pointers(ex_pointers);
handle_segfault(ex_pointers->ExceptionRecord->ExceptionCode);
handle_fatal_signal(ex_pointers->ExceptionRecord->ExceptionCode);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
......@@ -2481,161 +2478,6 @@ extern "C" char *my_demangle(const char *mangled_name, int *status)
#endif
extern "C" sig_handler handle_segfault(int sig)
{
time_t curr_time;
struct tm tm;
/*
Strictly speaking, one needs a mutex here
but since we have got SIGSEGV already, things are a mess
so not having the mutex is not as bad as possibly using a buggy
mutex - so we keep things simple
*/
if (segfaulted)
{
fprintf(stderr, "Fatal " SIGNAL_FMT " while backtracing\n", sig);
exit(1);
}
segfaulted = 1;
curr_time= my_time(0);
localtime_r(&curr_time, &tm);
fprintf(stderr,"\
%02d%02d%02d %2d:%02d:%02d - mysqld got " SIGNAL_FMT " ;\n\
This could be because you hit a bug. It is also possible that this binary\n\
or one of the libraries it was linked against is corrupt, improperly built,\n\
or misconfigured. This error can also be caused by malfunctioning hardware.\n",
tm.tm_year % 100, tm.tm_mon+1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec,
sig);
fprintf(stderr, "\
We will try our best to scrape up some info that will hopefully help diagnose\n\
the problem, but since we have already crashed, something is definitely wrong\n\
and this may fail.\n\n");
fprintf(stderr, "key_buffer_size=%lu\n",
(ulong) dflt_key_cache->key_cache_mem_size);
fprintf(stderr, "read_buffer_size=%ld\n", (long) global_system_variables.read_buff_size);
fprintf(stderr, "max_used_connections=%lu\n", max_used_connections);
fprintf(stderr, "max_threads=%u\n", thread_scheduler.max_threads);
fprintf(stderr, "threads_connected=%u\n", thread_count);
fprintf(stderr, "It is possible that mysqld could use up to \n\
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = %lu K\n\
bytes of memory\n", ((ulong) dflt_key_cache->key_cache_mem_size +
(global_system_variables.read_buff_size +
global_system_variables.sortbuff_size) *
thread_scheduler.max_threads +
max_connections * sizeof(THD)) / 1024);
fprintf(stderr, "Hope that's ok; if not, decrease some variables in the equation.\n\n");
#if defined(HAVE_LINUXTHREADS)
if (sizeof(char*) == 4 && thread_count > UNSAFE_DEFAULT_LINUX_THREADS)
{
fprintf(stderr, "\
You seem to be running 32-bit Linux and have %d concurrent connections.\n\
If you have not changed STACK_SIZE in LinuxThreads and built the binary \n\
yourself, LinuxThreads is quite likely to steal a part of the global heap for\n\
the thread stack. Please read http://dev.mysql.com/doc/mysql/en/linux.html\n\n",
thread_count);
}
#endif /* HAVE_LINUXTHREADS */
#ifdef HAVE_STACKTRACE
THD *thd=current_thd;
if (!(test_flags & TEST_NO_STACKTRACE))
{
fprintf(stderr, "Thread pointer: 0x%lx\n", (long) thd);
fprintf(stderr, "Attempting backtrace. You can use the following "
"information to find out\nwhere mysqld died. If "
"you see no messages after this, something went\n"
"terribly wrong...\n");
my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
my_thread_stack_size);
}
if (thd)
{
const char *kreason= "UNKNOWN";
switch (thd->killed) {
case THD::NOT_KILLED:
kreason= "NOT_KILLED";
break;
case THD::KILL_BAD_DATA:
kreason= "KILL_BAD_DATA";
break;
case THD::KILL_CONNECTION:
kreason= "KILL_CONNECTION";
break;
case THD::KILL_QUERY:
kreason= "KILL_QUERY";
break;
case THD::KILLED_NO_VALUE:
kreason= "KILLED_NO_VALUE";
break;
}
fprintf(stderr, "\nTrying to get some variables.\n"
"Some pointers may be invalid and cause the dump to abort.\n");
fprintf(stderr, "Query (%p): ", thd->query());
my_safe_print_str(thd->query(), min(1024, thd->query_length()));
fprintf(stderr, "Connection ID (thread ID): %lu\n", (ulong) thd->thread_id);
fprintf(stderr, "Status: %s\n", kreason);
fputc('\n', stderr);
}
fprintf(stderr, "\
The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains\n\
information that should help you find out what is causing the crash.\n");
fflush(stderr);
#endif /* HAVE_STACKTRACE */
#ifdef HAVE_INITGROUPS
if (calling_initgroups)
fprintf(stderr, "\n\
This crash occured while the server was calling initgroups(). This is\n\
often due to the use of a mysqld that is statically linked against glibc\n\
and configured to use LDAP in /etc/nsswitch.conf. You will need to either\n\
upgrade to a version of glibc that does not have this problem (2.3.4 or\n\
later when used with nscd), disable LDAP in your nsswitch.conf, or use a\n\
mysqld that is not statically linked.\n");
#endif
#ifdef HAVE_NPTL
if (thd_lib_detected == THD_LIB_LT && !getenv("LD_ASSUME_KERNEL"))
fprintf(stderr,"\n\
You are running a statically-linked LinuxThreads binary on an NPTL system.\n\
This can result in crashes on some distributions due to LT/NPTL conflicts.\n\
You should either build a dynamically-linked binary, or force LinuxThreads\n\
to be used with the LD_ASSUME_KERNEL environment variable. Please consult\n\
the documentation for your distribution on how to do that.\n");
#endif
if (locked_in_memory)
{
fprintf(stderr, "\n\
The \"--memlock\" argument, which was enabled, uses system calls that are\n\
unreliable and unstable on some operating systems and operating-system\n\
versions (notably, some versions of Linux). This crash could be due to use\n\
of those buggy OS calls. You should consider whether you really need the\n\
\"--memlock\" parameter and/or consult the OS distributer about \"mlockall\"\n\
bugs.\n");
}
#ifdef HAVE_WRITE_CORE
if (test_flags & TEST_CORE_ON_SIGNAL)
{
fprintf(stderr, "Writing a core file\n");
fflush(stderr);
my_write_core(sig);
}
#endif
#ifndef __WIN__
/* On Windows, do not terminate, but pass control to exception filter */
exit(1);
#endif
}
#if !defined(__WIN__) && !defined(__NETWARE__)
#ifndef SA_RESETHAND
#define SA_RESETHAND 0
......@@ -2664,9 +2506,9 @@ static void init_signals(void)
my_init_stacktrace();
#endif
#if defined(__amiga__)
sa.sa_handler=(void(*)())handle_segfault;
sa.sa_handler=(void(*)())handle_fatal_signal;
#else
sa.sa_handler=handle_segfault;
sa.sa_handler=handle_fatal_signal;
#endif
sigaction(SIGSEGV, &sa, NULL);
sigaction(SIGABRT, &sa, NULL);
......@@ -4363,6 +4205,10 @@ int win_main(int argc, char **argv)
int main(int argc, char **argv)
#endif
{
#ifdef HAVE_NPTL
ld_assume_kernel_is_set= (getenv("LD_ASSUME_KERNEL") != 0);
#endif
MY_INIT(argv[0]); // init my_sys library & pthreads
/* nothing should come before this line ^^^ */
......@@ -7876,7 +7722,7 @@ static int mysql_init_variables(void)
opt_secure_file_priv= 0;
opt_bootstrap= opt_myisam_log= 0;
mqh_used= 0;
segfaulted= kill_in_progress= 0;
kill_in_progress= 0;
cleanup_done= 0;
defaults_argc= 0;
defaults_argv= 0;
......
/* Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1307 USA */
#include "my_global.h"
#include <signal.h>
#include "mysql_priv.h"
#include "my_stacktrace.h"
#ifdef __WIN__
#include <crtdbg.h>
#define SIGNAL_FMT "exception 0x%x"
#else
#define SIGNAL_FMT "signal %d"
#endif
/*
We are handling signals in this file.
Any global variables we read should be 'volatile sig_atomic_t'
to guarantee that we read some consistent value.
*/
static volatile sig_atomic_t segfaulted= 0;
extern ulong max_used_connections;
extern volatile sig_atomic_t calling_initgroups;
#ifdef HAVE_NPTL
extern volatile sig_atomic_t ld_assume_kernel_is_set;
#endif
/**
* Handler for fatal signals
*
* Fatal events (seg.fault, bus error etc.) will trigger
* this signal handler. The handler will try to dump relevant
* debugging information to stderr and dump a core image.
*
* Signal handlers can only use a set of 'safe' system calls
* and library functions. A list of safe calls in POSIX systems
* are available at:
* http://pubs.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_04.html
* For MS Windows, guidelines are available at:
* http://msdn.microsoft.com/en-us/library/xdkz3x12(v=vs.71).aspx
*
* @param sig Signal number
*/
extern "C" sig_handler handle_fatal_signal(int sig)
{
if (segfaulted)
{
my_safe_printf_stderr("Fatal " SIGNAL_FMT " while backtracing\n", sig);
_exit(1); /* Quit without running destructors */
}
segfaulted = 1;
#ifdef __WIN__
SYSTEMTIME utc_time;
GetSystemTime(&utc_time);
const long hrs= utc_time.wHour;
const long mins= utc_time.wMinute;
const long secs= utc_time.wSecond;
#else
/* Using time() instead of my_time() to avoid looping */
const time_t curr_time= time(NULL);
/* Calculate time of day */
const long tmins = curr_time / 60;
const long thrs = tmins / 60;
const long hrs = thrs % 24;
const long mins = tmins % 60;
const long secs = curr_time % 60;
#endif
char hrs_buf[3]= "00";
char mins_buf[3]= "00";
char secs_buf[3]= "00";
my_safe_itoa(10, hrs, &hrs_buf[2]);
my_safe_itoa(10, mins, &mins_buf[2]);
my_safe_itoa(10, secs, &secs_buf[2]);
my_safe_printf_stderr("%s:%s:%s UTC - mysqld got " SIGNAL_FMT " ;\n",
hrs_buf, mins_buf, secs_buf, sig);
my_safe_printf_stderr("%s",
"This could be because you hit a bug. It is also possible that this binary\n"
"or one of the libraries it was linked against is corrupt, improperly built,\n"
"or misconfigured. This error can also be caused by malfunctioning hardware.\n");
my_safe_printf_stderr("%s",
"We will try our best to scrape up some info that will hopefully help\n"
"diagnose the problem, but since we have already crashed, \n"
"something is definitely wrong and this may fail.\n\n");
my_safe_printf_stderr("key_buffer_size=%lu\n",
(ulong) dflt_key_cache->key_cache_mem_size);
my_safe_printf_stderr("read_buffer_size=%ld\n",
(long) global_system_variables.read_buff_size);
my_safe_printf_stderr("max_used_connections=%lu\n",
(ulong) max_used_connections);
my_safe_printf_stderr("max_threads=%u\n",
(uint) thread_scheduler.max_threads);
my_safe_printf_stderr("thread_count=%u\n", (uint) thread_count);
my_safe_printf_stderr("connection_count=%u\n", (uint) connection_count);
my_safe_printf_stderr("It is possible that mysqld could use up to \n"
"key_buffer_size + "
"(read_buffer_size + sort_buffer_size)*max_threads = "
"%lu K bytes of memory\n",
((ulong) dflt_key_cache->key_cache_mem_size +
(global_system_variables.read_buff_size +
global_system_variables.sortbuff_size) *
thread_scheduler.max_threads +
max_connections * sizeof(THD)) / 1024);
my_safe_printf_stderr("%s",
"Hope that's ok; if not, decrease some variables in the equation.\n\n");
#if defined(HAVE_LINUXTHREADS)
if (sizeof(char*) == 4 && thread_count > UNSAFE_DEFAULT_LINUX_THREADS)
{
my_safe_printf_stderr(
"You seem to be running 32-bit Linux and have "
"%d concurrent connections.\n"
"If you have not changed STACK_SIZE in LinuxThreads "
"and built the binary \n"
"yourself, LinuxThreads is quite likely to steal "
"a part of the global heap for\n"
"the thread stack. Please read "
"http://dev.mysql.com/doc/mysql/en/linux-installation.html\n\n"
thread_count);
}
#endif /* HAVE_LINUXTHREADS */
#ifdef HAVE_STACKTRACE
THD *thd=current_thd;
if (!(test_flags & TEST_NO_STACKTRACE))
{
my_safe_printf_stderr("Thread pointer: 0x%p\n", thd);
my_safe_printf_stderr("%s",
"Attempting backtrace. You can use the following "
"information to find out\n"
"where mysqld died. If you see no messages after this, something went\n"
"terribly wrong...\n");
my_print_stacktrace(thd ? (uchar*) thd->thread_stack : NULL,
my_thread_stack_size);
}
if (thd)
{
const char *kreason= "UNKNOWN";
switch (thd->killed) {
case THD::NOT_KILLED:
kreason= "NOT_KILLED";
break;
case THD::KILL_BAD_DATA:
kreason= "KILL_BAD_DATA";
break;
case THD::KILL_CONNECTION:
kreason= "KILL_CONNECTION";
break;
case THD::KILL_QUERY:
kreason= "KILL_QUERY";
break;
case THD::KILLED_NO_VALUE:
kreason= "KILLED_NO_VALUE";
break;
}
my_safe_printf_stderr("%s", "\n"
"Trying to get some variables.\n"
"Some pointers may be invalid and cause the dump to abort.\n");
my_safe_printf_stderr("Query (%p): ", thd->query());
my_safe_print_str(thd->query(), min(1024U, thd->query_length()));
my_safe_printf_stderr("Connection ID (thread ID): %lu\n",
(ulong) thd->thread_id);
my_safe_printf_stderr("Status: %s\n\n", kreason);
}
my_safe_printf_stderr("%s",
"The manual page at "
"http://dev.mysql.com/doc/mysql/en/crashing.html contains\n"
"information that should help you find out what is causing the crash.\n");
#endif /* HAVE_STACKTRACE */
#ifdef HAVE_INITGROUPS
if (calling_initgroups)
{
my_safe_printf_stderr("%s", "\n"
"This crash occured while the server was calling initgroups(). This is\n"
"often due to the use of a mysqld that is statically linked against \n"
"glibc and configured to use LDAP in /etc/nsswitch.conf.\n"
"You will need to either upgrade to a version of glibc that does not\n"
"have this problem (2.3.4 or later when used with nscd),\n"
"disable LDAP in your nsswitch.conf, or use a "
"mysqld that is not statically linked.\n");
}
#endif
#ifdef HAVE_NPTL
if (thd_lib_detected == THD_LIB_LT && !ld_assume_kernel_is_set)
{
my_safe_printf_stderr("%s",
"You are running a statically-linked LinuxThreads binary on an NPTL\n"
"system. This can result in crashes on some distributions due to "
"LT/NPTL conflicts.\n"
"You should either build a dynamically-linked binary, "
"or force LinuxThreads\n"
"to be used with the LD_ASSUME_KERNEL environment variable.\n"
"Please consult the documentation for your distribution "
"on how to do that.\n");
}
#endif
if (locked_in_memory)
{
my_safe_printf_stderr("%s", "\n"
"The \"--memlock\" argument, which was enabled, "
"uses system calls that are\n"
"unreliable and unstable on some operating systems and "
"operating-system versions (notably, some versions of Linux).\n"
"This crash could be due to use of those buggy OS calls.\n"
"You should consider whether you really need the "
"\"--memlock\" parameter and/or consult the OS distributer about "
"\"mlockall\" bugs.\n");
}
#ifdef HAVE_WRITE_CORE
if (test_flags & TEST_CORE_ON_SIGNAL)
{
my_safe_printf_stderr("%s", "Writing a core file\n");
my_write_core(sig);
}
#endif
#ifndef __WIN__
/*
Quit, without running destructors (etc.)
On Windows, do not terminate, but pass control to exception filter.
*/
_exit(1); // Using _exit(), since exit() is not async signal safe
#endif
}
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