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| author | Sergei Trofimovich <siarheit@google.com> | 2023-09-28 20:20:31 +0100 |
|---|---|---|
| committer | Sergei Trofimovich <siarheit@google.com> | 2023-09-29 09:50:00 +0100 |
| commit | 7525707c5f3edb46958c4fdfbe30de5ddfa8923a (patch) | |
| tree | abb3184e5087e5466e3cf89a9ac203d387497de7 /gcc | |
| parent | bcc97edf8c9e40232fa30e7f0070057b6516fd77 (diff) | |
| download | gcc-7525707c5f3edb46958c4fdfbe30de5ddfa8923a.zip gcc-7525707c5f3edb46958c4fdfbe30de5ddfa8923a.tar.gz gcc-7525707c5f3edb46958c4fdfbe30de5ddfa8923a.tar.bz2 | |
ggc: do not wipe out unrelated data via gt_ggc_rtab [PR111505]
There are 3 GC root tables:
gt_ggc_rtab
gt_ggc_deletable_rtab
gt_pch_scalar_rtab
`deletable` and `scalar` tables are both simple: each element always
contains a pointer to the beginning of the object and it's size is the
full object.
`rtab` is different: it's `base` is a pointer in the middle of the
struct and `stride` points to the next GC pointer in the array.
Before the change there were 2 problems:
1. We memset()ed not just pointers but data around them.
2. We wen out of bounds of the last object described by gt_ggc_rtab
and triggered bootstrap failures in profile and asan bootstraps.
After the change we handle only pointers themselves like the rest of
ggc-common.cc code.
gcc/
PR middle-end/111505
* ggc-common.cc (ggc_zero_out_root_pointers, ggc_common_finalize):
Add new helper. Use helper instead of memset() to wipe out pointers.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ggc-common.cc | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/gcc/ggc-common.cc b/gcc/ggc-common.cc index 95803fa..39e2581 100644 --- a/gcc/ggc-common.cc +++ b/gcc/ggc-common.cc @@ -75,6 +75,18 @@ ggc_mark_root_tab (const_ggc_root_tab_t rt) (*rt->cb) (*(void **) ((char *)rt->base + rt->stride * i)); } +/* Zero out all the roots in the table RT. */ + +static void +ggc_zero_rtab_roots (const_ggc_root_tab_t rt) +{ + size_t i; + + for ( ; rt->base != NULL; rt++) + for (i = 0; i < rt->nelt; i++) + (*(void **) ((char *)rt->base + rt->stride * i)) = (void*)0; +} + /* Iterate through all registered roots and mark each element. */ void @@ -1307,8 +1319,7 @@ ggc_common_finalize () memset (rti->base, 0, rti->stride * rti->nelt); for (rt = gt_ggc_rtab; *rt; rt++) - for (rti = *rt; rti->base != NULL; rti++) - memset (rti->base, 0, rti->stride * rti->nelt); + ggc_zero_rtab_roots (*rt); for (rt = gt_pch_scalar_rtab; *rt; rt++) for (rti = *rt; rti->base != NULL; rti++) |