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| author | Ludovic Courtès <ludo@gnu.org> | 2016-11-09 21:20:00 +0100 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2016-11-09 21:24:44 +0100 |
| commit | 8033772363b287ca529461e575ceb4a69d7af942 (patch) | |
| tree | 696c581a27ea02b53c2599f616fecaa0b8865626 /gnu/packages/patches/gcc-strmov-store-file-names.patch | |
| parent | c169d91e5a0be92b6bd48a8fd98c43078d2a12ef (diff) | |
| download | guix-8033772363b287ca529461e575ceb4a69d7af942.tar guix-8033772363b287ca529461e575ceb4a69d7af942.tar.gz | |
gnu: gcc@5, gcc@6: Work around use of 'movabs' for /gnu/store strings.
Partly addresses <http://bugs.gnu.org/24703>.
Reported by Mark H Weaver <mhw@netris.org>.
* 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.
Diffstat (limited to 'gnu/packages/patches/gcc-strmov-store-file-names.patch')
| -rw-r--r-- | gnu/packages/patches/gcc-strmov-store-file-names.patch | 66 |
1 files changed, 66 insertions, 0 deletions
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 <http://bugs.gnu.org/24703>. + +--- 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 ++ <http://bugs.gnu.org/24703>. */ ++ 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; |