diff options
Diffstat (limited to 'recipes-kernel/linux/linux-intel/objtool-fix-segfault-with-clang.patch')
-rw-r--r-- | recipes-kernel/linux/linux-intel/objtool-fix-segfault-with-clang.patch | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/recipes-kernel/linux/linux-intel/objtool-fix-segfault-with-clang.patch b/recipes-kernel/linux/linux-intel/objtool-fix-segfault-with-clang.patch new file mode 100644 index 00000000..f4b1374f --- /dev/null +++ b/recipes-kernel/linux/linux-intel/objtool-fix-segfault-with-clang.patch | |||
@@ -0,0 +1,150 @@ | |||
1 | From 44f6a7c0755d8dd453c70557e11687bb080a6f21 Mon Sep 17 00:00:00 2001 | ||
2 | From: Josh Poimboeuf <jpoimboe@redhat.com> | ||
3 | Date: Mon, 14 Dec 2020 16:04:20 -0600 | ||
4 | Subject: [PATCH] objtool: Fix seg fault with Clang non-section symbols | ||
5 | |||
6 | The Clang assembler likes to strip section symbols, which means objtool | ||
7 | can't reference some text code by its section. This confuses objtool | ||
8 | greatly, causing it to seg fault. | ||
9 | |||
10 | The fix is similar to what was done before, for ORC reloc generation: | ||
11 | |||
12 | e81e07244325 ("objtool: Support Clang non-section symbols in ORC generation") | ||
13 | |||
14 | Factor out that code into a common helper and use it for static call | ||
15 | reloc generation as well. | ||
16 | |||
17 | Reported-by: Arnd Bergmann <arnd@kernel.org> | ||
18 | Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> | ||
19 | Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> | ||
20 | Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> | ||
21 | Reviewed-by: Miroslav Benes <mbenes@suse.cz> | ||
22 | Link: https://github.com/ClangBuiltLinux/linux/issues/1207 | ||
23 | Link: https://lkml.kernel.org/r/ba6b6c0f0dd5acbba66e403955a967d9fdd1726a.1607983452.git.jpoimboe@redhat.com | ||
24 | |||
25 | Upstream-Status: Backport | ||
26 | Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> | ||
27 | --- | ||
28 | tools/objtool/check.c | 11 +++++++++-- | ||
29 | tools/objtool/elf.c | 26 ++++++++++++++++++++++++++ | ||
30 | tools/objtool/elf.h | 2 ++ | ||
31 | tools/objtool/orc_gen.c | 29 +++++------------------------ | ||
32 | 4 files changed, 42 insertions(+), 26 deletions(-) | ||
33 | |||
34 | diff --git a/tools/objtool/check.c b/tools/objtool/check.c | ||
35 | index c6ab44543c92a..5f8d3eed78a18 100644 | ||
36 | --- a/tools/objtool/check.c | ||
37 | +++ b/tools/objtool/check.c | ||
38 | @@ -467,13 +467,20 @@ static int create_static_call_sections(struct objtool_file *file) | ||
39 | |||
40 | /* populate reloc for 'addr' */ | ||
41 | reloc = malloc(sizeof(*reloc)); | ||
42 | + | ||
43 | if (!reloc) { | ||
44 | perror("malloc"); | ||
45 | return -1; | ||
46 | } | ||
47 | memset(reloc, 0, sizeof(*reloc)); | ||
48 | - reloc->sym = insn->sec->sym; | ||
49 | - reloc->addend = insn->offset; | ||
50 | + | ||
51 | + insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc); | ||
52 | + if (!reloc->sym) { | ||
53 | + WARN_FUNC("static call tramp: missing containing symbol", | ||
54 | + insn->sec, insn->offset); | ||
55 | + return -1; | ||
56 | + } | ||
57 | + | ||
58 | reloc->type = R_X86_64_PC32; | ||
59 | reloc->offset = idx * sizeof(struct static_call_site); | ||
60 | reloc->sec = reloc_sec; | ||
61 | diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c | ||
62 | index 4e1d7460574b4..be89c741ba9a0 100644 | ||
63 | --- a/tools/objtool/elf.c | ||
64 | +++ b/tools/objtool/elf.c | ||
65 | @@ -262,6 +262,32 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns | ||
66 | return find_reloc_by_dest_range(elf, sec, offset, 1); | ||
67 | } | ||
68 | |||
69 | +void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset, | ||
70 | + struct reloc *reloc) | ||
71 | +{ | ||
72 | + if (sec->sym) { | ||
73 | + reloc->sym = sec->sym; | ||
74 | + reloc->addend = offset; | ||
75 | + return; | ||
76 | + } | ||
77 | + | ||
78 | + /* | ||
79 | + * The Clang assembler strips section symbols, so we have to reference | ||
80 | + * the function symbol instead: | ||
81 | + */ | ||
82 | + reloc->sym = find_symbol_containing(sec, offset); | ||
83 | + if (!reloc->sym) { | ||
84 | + /* | ||
85 | + * Hack alert. This happens when we need to reference the NOP | ||
86 | + * pad insn immediately after the function. | ||
87 | + */ | ||
88 | + reloc->sym = find_symbol_containing(sec, offset - 1); | ||
89 | + } | ||
90 | + | ||
91 | + if (reloc->sym) | ||
92 | + reloc->addend = offset - reloc->sym->offset; | ||
93 | +} | ||
94 | + | ||
95 | static int read_sections(struct elf *elf) | ||
96 | { | ||
97 | Elf_Scn *s = NULL; | ||
98 | diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h | ||
99 | index 807f8c6700974..e6890cc70a25b 100644 | ||
100 | --- a/tools/objtool/elf.h | ||
101 | +++ b/tools/objtool/elf.h | ||
102 | @@ -140,6 +140,8 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns | ||
103 | struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec, | ||
104 | unsigned long offset, unsigned int len); | ||
105 | struct symbol *find_func_containing(struct section *sec, unsigned long offset); | ||
106 | +void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset, | ||
107 | + struct reloc *reloc); | ||
108 | int elf_rebuild_reloc_section(struct elf *elf, struct section *sec); | ||
109 | |||
110 | #define for_each_sec(file, sec) \ | ||
111 | diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c | ||
112 | index 235663b96adc7..9ce68b385a1b8 100644 | ||
113 | --- a/tools/objtool/orc_gen.c | ||
114 | +++ b/tools/objtool/orc_gen.c | ||
115 | @@ -105,30 +105,11 @@ static int create_orc_entry(struct elf *elf, struct section *u_sec, struct secti | ||
116 | } | ||
117 | memset(reloc, 0, sizeof(*reloc)); | ||
118 | |||
119 | - if (insn_sec->sym) { | ||
120 | - reloc->sym = insn_sec->sym; | ||
121 | - reloc->addend = insn_off; | ||
122 | - } else { | ||
123 | - /* | ||
124 | - * The Clang assembler doesn't produce section symbols, so we | ||
125 | - * have to reference the function symbol instead: | ||
126 | - */ | ||
127 | - reloc->sym = find_symbol_containing(insn_sec, insn_off); | ||
128 | - if (!reloc->sym) { | ||
129 | - /* | ||
130 | - * Hack alert. This happens when we need to reference | ||
131 | - * the NOP pad insn immediately after the function. | ||
132 | - */ | ||
133 | - reloc->sym = find_symbol_containing(insn_sec, | ||
134 | - insn_off - 1); | ||
135 | - } | ||
136 | - if (!reloc->sym) { | ||
137 | - WARN("missing symbol for insn at offset 0x%lx\n", | ||
138 | - insn_off); | ||
139 | - return -1; | ||
140 | - } | ||
141 | - | ||
142 | - reloc->addend = insn_off - reloc->sym->offset; | ||
143 | + insn_to_reloc_sym_addend(insn_sec, insn_off, reloc); | ||
144 | + if (!reloc->sym) { | ||
145 | + WARN("missing symbol for insn at offset 0x%lx", | ||
146 | + insn_off); | ||
147 | + return -1; | ||
148 | } | ||
149 | |||
150 | reloc->type = R_X86_64_PC32; | ||