From 8033772363b287ca529461e575ceb4a69d7af942 Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Wed, 9 Nov 2016 21:20:00 +0100 Subject: gnu: gcc@5, gcc@6: Work around use of 'movabs' for /gnu/store strings. Partly addresses . Reported by Mark H Weaver . * gnu/packages/patches/gcc-strmov-store-file-names.patch: New file. * gnu/local.mk (dist_patch_DATA): Add it. * gnu/packages/gcc.scm (gcc-5)[sources](patches): Add it. (gcc-6)[sources](patches): Add it. --- gnu/local.mk | 1 + gnu/packages/gcc.scm | 6 +- .../patches/gcc-strmov-store-file-names.patch | 66 ++++++++++++++++++++++ 3 files changed, 71 insertions(+), 2 deletions(-) create mode 100644 gnu/packages/patches/gcc-strmov-store-file-names.patch diff --git a/gnu/local.mk b/gnu/local.mk index 6e152eb005..b3a4cd5a88 100644 --- a/gnu/local.mk +++ b/gnu/local.mk @@ -543,6 +543,7 @@ dist_patch_DATA = \ %D%/packages/patches/gcc-arm-link-spec-fix.patch \ %D%/packages/patches/gcc-cross-environment-variables.patch \ %D%/packages/patches/gcc-libvtv-runpath.patch \ + %D%/packages/patches/gcc-strmov-store-file-names.patch \ %D%/packages/patches/gcc-5.0-libvtv-runpath.patch \ %D%/packages/patches/gcc-6-arm-none-eabi-multilib.patch \ %D%/packages/patches/gcc-6-cross-environment-variables.patch \ diff --git a/gnu/packages/gcc.scm b/gnu/packages/gcc.scm index c961c84fca..1fad9da663 100644 --- a/gnu/packages/gcc.scm +++ b/gnu/packages/gcc.scm @@ -354,7 +354,8 @@ Go. It also includes runtime support libraries for these languages.") (sha256 (base32 "1ny4smkp5bzs3cp8ss7pl6lk8yss0d9m4av1mvdp72r1x695akxq")) - (patches (search-patches "gcc-5.0-libvtv-runpath.patch")))))) + (patches (search-patches "gcc-strmov-store-file-names.patch" + "gcc-5.0-libvtv-runpath.patch")))))) (define-public gcc-6 (package @@ -367,7 +368,8 @@ Go. It also includes runtime support libraries for these languages.") (sha256 (base32 "1idpf43988v1a6i8lw9ak1r7igcfg1bm5kn011iydlr2qygmhi4r")) - (patches (search-patches "gcc-5.0-libvtv-runpath.patch")))))) + (patches (search-patches "gcc-strmov-store-file-names.patch" + "gcc-5.0-libvtv-runpath.patch")))))) ;; Note: When changing the default gcc version, update ;; the gcc-toolchain-* definitions accordingly. diff --git a/gnu/packages/patches/gcc-strmov-store-file-names.patch b/gnu/packages/patches/gcc-strmov-store-file-names.patch new file mode 100644 index 0000000000..7951b87616 --- /dev/null +++ b/gnu/packages/patches/gcc-strmov-store-file-names.patch @@ -0,0 +1,66 @@ +Make sure that statements such as: + + strcpy (dst, "/gnu/store/…"); + +do not result in chunked /gnu/store strings that are undetectable by +Guix's GC and its grafting code. See . + +--- gcc-5.3.0/gcc/builtins.c 2016-10-18 10:50:46.080616285 +0200 ++++ gcc-5.3.0/gcc/builtins.c 2016-11-09 15:26:43.693042737 +0100 +@@ -3192,6 +3192,42 @@ determine_block_size (tree len, rtx len_ + GET_MODE_MASK (GET_MODE (len_rtx))); + } + ++/* Return true if STR contains the string "/gnu/store". */ ++ ++static bool ++store_reference_p (tree str) ++{ ++ if (TREE_CODE (str) == ADDR_EXPR) ++ str = TREE_OPERAND (str, 0); ++ ++ if (TREE_CODE (str) != STRING_CST) ++ return false; ++ ++ int len; ++ const char *store; ++ ++ store = getenv ("NIX_STORE") ? getenv ("NIX_STORE") : "/gnu/store"; ++ len = strlen (store); ++ ++ /* Size of the hash part of store file names, including leading slash and ++ trailing hyphen. */ ++ const int hash_len = 34; ++ ++ if (TREE_STRING_LENGTH (str) < len + hash_len) ++ return false; ++ ++ /* We cannot use 'strstr' because 'TREE_STRING_POINTER' returns a string ++ that is not necessarily NUL-terminated. */ ++ ++ for (int i = 0; i < TREE_STRING_LENGTH (str) - (len + hash_len); i++) ++ { ++ if (strncmp (TREE_STRING_POINTER (str) + i, store, len) == 0) ++ return true; ++ } ++ ++ return false; ++} ++ + /* Helper function to do the actual work for expand_builtin_memcpy. */ + + static rtx +@@ -3207,6 +3243,13 @@ expand_builtin_memcpy_args (tree dest, t + unsigned HOST_WIDE_INT max_size; + unsigned HOST_WIDE_INT probable_max_size; + ++ /* Do not emit block moves, which translate to the 'movabs' instruction on ++ x86_64, when SRC refers to store items. That way, store references ++ remain visible to the Guix GC and grafting code. See ++ . */ ++ if (store_reference_p (src)) ++ return NULL_RTX; ++ + /* If DEST is not a pointer type, call the normal function. */ + if (dest_align == 0) + return NULL_RTX; -- cgit v1.2.3