diff --git a/elf/dl-printf.c b/elf/dl-printf.c index 00c114002c..1b55c87cfd 100644 --- a/elf/dl-printf.c +++ b/elf/dl-printf.c @@ -27,6 +27,7 @@ #include #include #include +#include /* Bare-bones printf implementation. This function only knows about the formats and flags needed and can handle only up to 64 stripes in @@ -36,6 +37,9 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg) { # define NIOVMAX 64 struct iovec iov[NIOVMAX]; + /* Maximum size for 'd', 'u', and 'x' including padding. */ + enum { IFMTSIZE = INT_STRLEN_BOUND(void *) }; + char ifmtbuf[NIOVMAX][IFMTSIZE]; int niov = 0; pid_t pid = 0; char pidbuf[12]; @@ -100,6 +104,8 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg) if (*fmt == '*') { width = va_arg (arg, int); + /* The maximum padding accepted is up to pointer size. */ + assert (width < IFMTSIZE); ++fmt; } @@ -160,14 +166,7 @@ _dl_debug_vdprintf (int fd, int tag_p, const char *fmt, va_list arg) #endif } - /* We use alloca() to allocate the buffer with the most - pessimistic guess for the size. Using alloca() allows - having more than one integer formatting in a call. */ - int size = 1 + 3 * sizeof (unsigned long int); - if (width + 1 > size) - size = width + 1; - char *buf = (char *) alloca (size); - char *endp = &buf[size]; + char *endp = &ifmtbuf[niov][IFMTSIZE]; char *cp = _itoa (num, endp, *fmt == 'x' ? 16 : 10, 0); /* Pad to the width the user specified. */