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| author | Peter Zhu <peter@peterzhu.ca> | 2023-04-04 09:27:45 -0400 |
|---|---|---|
| committer | Peter Zhu <peter@peterzhu.ca> | 2023-04-04 11:12:07 -0400 |
| commit | a84c99468f26a9f79fec57926d561ed906505eac (patch) | |
| tree | 86c94feef11c4682f4330ed67dc3bc2be15a09d5 /timev.h | |
| parent | 06da0d1456f52a69ad19a0a8cc35e3359d2d144c (diff) | |
| download | ruby-a84c99468f26a9f79fec57926d561ed906505eac.tar.gz | |
Fix crash in Time on 32-bit systems
[Bug #19575]
struct vtm is packed causing it to have a size that is not aligned on
32-bit systems. When allocating it on the stack, it will have unaligned
addresses which means that the fields won't be marked by the GC when
scanning the stack (since the GC only marks aligned addresses). This can
cause crashes when the fields are heap allocated objects like Bignums.
This commit moves the flags in struct time_object into struct vtm for
space efficiency and removes the need for packing.
This is an example of a crash:
ruby(rb_print_backtrace+0xd) [0x56848945] ../src/vm_dump.c:785
ruby(rb_vm_bugreport) ../src/vm_dump.c:1101
ruby(rb_assert_failure+0x7a) [0x56671857] ../src/error.c:878
ruby(vm_search_cc+0x0) [0x56666e47] ../src/vm_method.c:1366
ruby(rb_vm_search_method_slowpath) ../src/vm_insnhelper.c:2090
ruby(callable_method_entry+0x5) [0x568232d3] ../src/vm_method.c:1406
ruby(rb_callable_method_entry) ../src/vm_method.c:1413
ruby(gccct_method_search_slowpath) ../src/vm_eval.c:427
ruby(gccct_method_search+0x20f) [0x568237ef] ../src/vm_eval.c:476
ruby(opt_equality_by_mid_slowpath+0x2c) [0x5682388c] ../src/vm_insnhelper.c:2338
ruby(rb_equal+0x37) [0x566fe577] ../src/object.c:133
ruby(rb_big_eq+0x34) [0x56876ee4] ../src/bignum.c:5554
ruby(rb_int_equal+0x14) [0x566f3ed4] ../src/numeric.c:4640
ruby(rb_int_equal) ../src/numeric.c:4634
ruby(vm_call0_cfunc_with_frame+0x6d) [0x568303c2] ../src/vm_eval.c:148
ruby(vm_call0_cfunc) ../src/vm_eval.c:162
ruby(vm_call0_body) ../src/vm_eval.c:208
ruby(rb_funcallv_scope+0xd1) [0x56833971] ../src/vm_eval.c:85
ruby(RB_TEST+0x0) [0x567e8488] ../src/time.c:78
ruby(eq) ../src/time.c:78
ruby(small_vtm_sub) ../src/time.c:1523
ruby(timelocalw+0x23b) [0x567f3e9b] ../src/time.c:1593
ruby(time_s_alloc+0x0) [0x567f536b] ../src/time.c:3698
ruby(time_new_timew) ../src/time.c:2694
ruby(time_s_mktime) ../src/time.c:3698
Diffstat (limited to 'timev.h')
| -rw-r--r-- | timev.h | 7 |
1 files changed, 5 insertions, 2 deletions
@@ -2,7 +2,6 @@ #define RUBY_TIMEV_H #include "ruby/ruby.h" -RBIMPL_ATTR_PACKED_STRUCT_UNALIGNED_BEGIN() struct vtm { VALUE year; /* 2000 for example. Integer. */ VALUE subsecx; /* 0 <= subsecx < TIME_SCALE. possibly Rational. */ @@ -16,7 +15,11 @@ struct vtm { unsigned int sec:6; /* 0..60 */ unsigned int wday:3; /* 0:Sunday, 1:Monday, ..., 6:Saturday 7:init */ unsigned int isdst:2; /* 0:StandardTime 1:DayLightSavingTime 3:init */ -} RBIMPL_ATTR_PACKED_STRUCT_UNALIGNED_END(); + + /* Flags for struct time_object */ + unsigned int tzmode:3; /* 0:localtime 1:utc 2:fixoff 3:uninitialized */ + unsigned int tm_got:1; +}; #define TIME_SCALE 1000000000 |