diff options
Diffstat (limited to 'mysys/stacktrace.c')
| -rw-r--r-- | mysys/stacktrace.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/mysys/stacktrace.c b/mysys/stacktrace.c index 4cc767f924d..395659238b3 100644 --- a/mysys/stacktrace.c +++ b/mysys/stacktrace.c @@ -129,13 +129,32 @@ static int safe_print_str(const char *addr, int max_len) #endif -void my_safe_print_str(const char* val, int max_len) +/* + Attempt to print a char * pointer as a string. + + SYNOPSIS + Prints either until the end of string ('\0'), or max_len characters have + been printed. + + RETURN VALUE + 0 Pointer was within the heap address space. + The string was printed fully, or until the end of the heap address space. + 1 Pointer is outside the heap address space. Printed as invalid. + + NOTE + On some systems, we can have valid pointers outside the heap address space. + This is through the use of mmap inside malloc calls. When this function + returns 1, it does not mean 100% that the pointer is corrupted. +*/ + +int my_safe_print_str(const char* val, int max_len) { char *heap_end; #ifdef __linux__ + // Try and make use of /proc filesystem to safely print memory contents. if (!safe_print_str(val, max_len)) - return; + return 0; #endif heap_end= (char*) sbrk(0); @@ -143,12 +162,14 @@ void my_safe_print_str(const char* val, int max_len) if (!PTR_SANE(val)) { my_safe_printf_stderr("%s", "is an invalid pointer"); - return; + return 1; } for (; max_len && PTR_SANE(val) && *val; --max_len) my_write_stderr((val++), 1); my_safe_printf_stderr("%s", "\n"); + + return 0; } #if defined(HAVE_PRINTSTACK) @@ -727,7 +748,7 @@ void my_write_core(int unused) } -void my_safe_print_str(const char *val, int len) +int my_safe_print_str(const char *val, int len) { __try { @@ -737,6 +758,7 @@ void my_safe_print_str(const char *val, int len) { my_safe_printf_stderr("%s", "is an invalid string pointer"); } + return 0; } #endif /*__WIN__*/ |