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-rw-r--r--meta/recipes-core/glibc/glibc/0036-i386-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch124
1 files changed, 124 insertions, 0 deletions
diff --git a/meta/recipes-core/glibc/glibc/0036-i386-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch b/meta/recipes-core/glibc/glibc/0036-i386-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch
new file mode 100644
index 0000000000..ad0a1147aa
--- /dev/null
+++ b/meta/recipes-core/glibc/glibc/0036-i386-Avoid-lazy-relocation-of-tlsdesc-BZ-27137.patch
@@ -0,0 +1,124 @@
1From ddcacd91cc10ff92d6201eda87047d029c14158d Mon Sep 17 00:00:00 2001
2From: Szabolcs Nagy <szabolcs.nagy@arm.com>
3Date: Thu, 11 Feb 2021 11:40:11 +0000
4Subject: [PATCH] i386: Avoid lazy relocation of tlsdesc [BZ #27137]
5
6Lazy tlsdesc relocation is racy because the static tls optimization and
7tlsdesc management operations are done without holding the dlopen lock.
8
9This similar to the commit b7cf203b5c17dd6d9878537d41e0c7cc3d270a67
10for aarch64, but it fixes a different race: bug 27137.
11
12On i386 the code is a bit more complicated than on x86_64 because both
13rel and rela relocs are supported.
14---
15 sysdeps/i386/dl-machine.h | 76 ++++++++++++++++++---------------------
16 1 file changed, 34 insertions(+), 42 deletions(-)
17---
18Upstream-Status: Backport [https://sourceware.org/git/?p=glibc.git;a=patch;h=ddcacd91cc10ff92d6201eda87047d029c14158d]
19Signed-off-by: Akash Hadke <akash.hadke@kpit.com>
20Signed-off-by: Akash Hadke <hadkeakash4@gmail.com>
21---
22diff --git a/sysdeps/i386/dl-machine.h b/sysdeps/i386/dl-machine.h
23index 23e9cc3bfb..590b41d8d7 100644
24--- a/sysdeps/i386/dl-machine.h
25+++ b/sysdeps/i386/dl-machine.h
26@@ -688,50 +688,32 @@ elf_machine_lazy_rel (struct link_map *map,
27 }
28 else if (__glibc_likely (r_type == R_386_TLS_DESC))
29 {
30- struct tlsdesc volatile * __attribute__((__unused__)) td =
31- (struct tlsdesc volatile *)reloc_addr;
32-
33- /* Handle relocations that reference the local *ABS* in a simple
34- way, so as to preserve a potential addend. */
35- if (ELF32_R_SYM (reloc->r_info) == 0)
36- td->entry = _dl_tlsdesc_resolve_abs_plus_addend;
37- /* Given a known-zero addend, we can store a pointer to the
38- reloc in the arg position. */
39- else if (td->arg == 0)
40- {
41- td->arg = (void*)reloc;
42- td->entry = _dl_tlsdesc_resolve_rel;
43- }
44- else
45- {
46- /* We could handle non-*ABS* relocations with non-zero addends
47- by allocating dynamically an arg to hold a pointer to the
48- reloc, but that sounds pointless. */
49- const Elf32_Rel *const r = reloc;
50- /* The code below was borrowed from elf_dynamic_do_rel(). */
51- const ElfW(Sym) *const symtab =
52- (const void *) D_PTR (map, l_info[DT_SYMTAB]);
53+ const Elf32_Rel *const r = reloc;
54+ /* The code below was borrowed from elf_dynamic_do_rel(). */
55+ const ElfW(Sym) *const symtab =
56+ (const void *) D_PTR (map, l_info[DT_SYMTAB]);
57
58+ /* Always initialize TLS descriptors completely at load time, in
59+ case static TLS is allocated for it that requires locking. */
60 # ifdef RTLD_BOOTSTRAP
61- /* The dynamic linker always uses versioning. */
62- assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL);
63+ /* The dynamic linker always uses versioning. */
64+ assert (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL);
65 # else
66- if (map->l_info[VERSYMIDX (DT_VERSYM)])
67+ if (map->l_info[VERSYMIDX (DT_VERSYM)])
68 # endif
69- {
70- const ElfW(Half) *const version =
71- (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
72- ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
73- elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
74- &map->l_versions[ndx],
75- (void *) (l_addr + r->r_offset), skip_ifunc);
76- }
77+ {
78+ const ElfW(Half) *const version =
79+ (const void *) D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
80+ ElfW(Half) ndx = version[ELFW(R_SYM) (r->r_info)] & 0x7fff;
81+ elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)],
82+ &map->l_versions[ndx],
83+ (void *) (l_addr + r->r_offset), skip_ifunc);
84+ }
85 # ifndef RTLD_BOOTSTRAP
86- else
87- elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
88- (void *) (l_addr + r->r_offset), skip_ifunc);
89+ else
90+ elf_machine_rel (map, r, &symtab[ELFW(R_SYM) (r->r_info)], NULL,
91+ (void *) (l_addr + r->r_offset), skip_ifunc);
92 # endif
93- }
94 }
95 else if (__glibc_unlikely (r_type == R_386_IRELATIVE))
96 {
97@@ -758,11 +740,21 @@ elf_machine_lazy_rela (struct link_map *map,
98 ;
99 else if (__glibc_likely (r_type == R_386_TLS_DESC))
100 {
101- struct tlsdesc volatile * __attribute__((__unused__)) td =
102- (struct tlsdesc volatile *)reloc_addr;
103+ const Elf_Symndx symndx = ELFW (R_SYM) (reloc->r_info);
104+ const ElfW (Sym) *symtab = (const void *)D_PTR (map, l_info[DT_SYMTAB]);
105+ const ElfW (Sym) *sym = &symtab[symndx];
106+ const struct r_found_version *version = NULL;
107+
108+ if (map->l_info[VERSYMIDX (DT_VERSYM)] != NULL)
109+ {
110+ const ElfW (Half) *vernum =
111+ (const void *)D_PTR (map, l_info[VERSYMIDX (DT_VERSYM)]);
112+ version = &map->l_versions[vernum[symndx] & 0x7fff];
113+ }
114
115- td->arg = (void*)reloc;
116- td->entry = _dl_tlsdesc_resolve_rela;
117+ /* Always initialize TLS descriptors completely at load time, in
118+ case static TLS is allocated for it that requires locking. */
119+ elf_machine_rela (map, reloc, sym, version, reloc_addr, skip_ifunc);
120 }
121 else if (__glibc_unlikely (r_type == R_386_IRELATIVE))
122 {
123--
1242.27.0
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