From bf1473d0c1b099b8d919835cc430b99606134aab Mon Sep 17 00:00:00 2001 From: Paul Gortmaker Date: Thu, 26 Jun 2014 15:08:47 -0400 Subject: recipes-devtools: fix segfault in lib32-gcc with "." multilib_dir When enabling a lib32-gcc in a 64 bit build, without doing any other configuration, the mutilib dir is unspecified, which is represented internally in gcc as "." and as such uncovers an invalid free on a non-malloc'd pointer. As suggested by the gcc folks, simply make sure the "." case is also stored in a malloc'd pointer, so that the intended runtime behaviour of the code remains unchanged. Patch has been accepted by upstream maintainers of gcc. Signed-off-by: Paul Gortmaker Signed-off-by: Richard Purdie --- meta/recipes-devtools/gcc/gcc-4.9.inc | 1 + ...fault-from-calling-free-on-non-malloc-d-a.patch | 66 ++++++++++++++++++++++ 2 files changed, 67 insertions(+) create mode 100644 meta/recipes-devtools/gcc/gcc-4.9/0053-gcc-fix-segfault-from-calling-free-on-non-malloc-d-a.patch diff --git a/meta/recipes-devtools/gcc/gcc-4.9.inc b/meta/recipes-devtools/gcc/gcc-4.9.inc index 185dbba822..cbf1355fcb 100644 --- a/meta/recipes-devtools/gcc/gcc-4.9.inc +++ b/meta/recipes-devtools/gcc/gcc-4.9.inc @@ -66,6 +66,7 @@ SRC_URI = "${GNU_MIRROR}/gcc/gcc-${PV}/gcc-${PV}.tar.bz2 \ file://0050-Revert-Use-dbx_reg_number-for-spanning-registers.patch \ file://0051-eabispe.patch \ file://0052-Fix-GCC-targeting-E500-SPE-errors-with-the-_Decimal64-type.patch \ + file://0053-gcc-fix-segfault-from-calling-free-on-non-malloc-d-a.patch \ " SRC_URI[md5sum] = "9709b49ae0e904cbb0a6a1b62853b556" SRC_URI[sha256sum] = "b9b047a97bade9c1c89970bc8e211ff57b7b8998a1730a80a653d329f8ed1257" diff --git a/meta/recipes-devtools/gcc/gcc-4.9/0053-gcc-fix-segfault-from-calling-free-on-non-malloc-d-a.patch b/meta/recipes-devtools/gcc/gcc-4.9/0053-gcc-fix-segfault-from-calling-free-on-non-malloc-d-a.patch new file mode 100644 index 0000000000..23b445c9eb --- /dev/null +++ b/meta/recipes-devtools/gcc/gcc-4.9/0053-gcc-fix-segfault-from-calling-free-on-non-malloc-d-a.patch @@ -0,0 +1,66 @@ +From a22a222c8f9299f6c07a0274388ade7d4ab8c28d Mon Sep 17 00:00:00 2001 +From: Paul Gortmaker +Date: Fri, 20 Jun 2014 16:41:08 -0400 +Subject: [PATCH] gcc: fix segfault from calling free on non-malloc'd area + +We see the following on a 32bit gcc installed on 64 bit host: + + Reading symbols from ./i586-pokymllib32-linux-gcc...done. + (gdb) run + Starting program: x86-pokymllib32-linux/lib32-gcc/4.9.0-r0/image/usr/bin/i586-pokymllib32-linux-gcc + + Program received signal SIGSEGV, Segmentation fault. + 0xf7e957e0 in free () from /lib/i386-linux-gnu/libc.so.6 + (gdb) bt + #0 0xf7e957e0 in free () from /lib/i386-linux-gnu/libc.so.6 + #1 0x0804b73c in set_multilib_dir () at gcc-4.9.0/gcc/gcc.c:7827 + #2 main (argc=1, argv=0xffffd504) at gcc-4.9.0/gcc/gcc.c:6688 + (gdb) + +The problem arises because we conditionally assign the pointer we +eventually free, and the conditional may assign the pointer to the +non-malloc'd internal string "." which fails when we free it here: + + if (multilib_dir == NULL && multilib_os_dir != NULL + && strcmp (multilib_os_dir, ".") == 0) + { + free (CONST_CAST (char *, multilib_os_dir)); + ... + +As suggested by Jakub, ensure the "." case is also malloc'd via +xstrdup() and hence the pointer for the "." case can be freed. + +Cc: Jakub Jelinek +Cc: Jeff Law +Cc: Matthias Klose +CC: Tobias Burnus +Upstream-Status: Accepted [ https://gcc.gnu.org/ml/gcc-patches/2014-06/msg02069.html ] +Signed-off-by: Paul Gortmaker + +diff --git a/gcc/gcc.c b/gcc/gcc.c +index 9ac18e60d801..168acf7eb0c9 100644 +--- a/gcc/gcc.c ++++ b/gcc/gcc.c +@@ -7790,10 +7790,15 @@ set_multilib_dir (void) + q2++; + if (*q2 == ':') + ml_end = q2; +- new_multilib_os_dir = XNEWVEC (char, ml_end - q); +- memcpy (new_multilib_os_dir, q + 1, ml_end - q - 1); +- new_multilib_os_dir[ml_end - q - 1] = '\0'; +- multilib_os_dir = *new_multilib_os_dir ? new_multilib_os_dir : "."; ++ if (ml_end - q == 1) ++ multilib_os_dir = xstrdup ("."); ++ else ++ { ++ new_multilib_os_dir = XNEWVEC (char, ml_end - q); ++ memcpy (new_multilib_os_dir, q + 1, ml_end - q - 1); ++ new_multilib_os_dir[ml_end - q - 1] = '\0'; ++ multilib_os_dir = new_multilib_os_dir; ++ } + + if (q2 < end && *q2 == ':') + { +-- +1.9.2 + -- cgit 1.2.3-korg