Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"The main thing is a fix to our FUTEX_WAKE_OP implementation which was
unbelievably broken, but did actually work for the one scenario that
GLIBC used to use.
Summary:
- Fix stack unwinding so we ignore user stacks
- Fix ftrace module PLT trampoline initialisation checks
- Fix terminally broken implementation of FUTEX_WAKE_OP atomics"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: futex: Fix FUTEX_WAKE_OP atomic ops with non-zero result value
arm64: backtrace: Don't bother trying to unwind the userspace stack
arm64/ftrace: fix inadvertent BUG() in trampoline check
+23
-16
+8
-8
arch/arm64/include/asm/futex.h
+8
-8
arch/arm64/include/asm/futex.h
···
30
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" prfm pstl1strm, %2\n" \
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"1: ldxr %w1, %2\n" \
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insn "\n" \
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-
"2: stlxr %w3, %w0, %2\n" \
34
-
" cbnz %w3, 1b\n" \
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+
"2: stlxr %w0, %w3, %2\n" \
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+
" cbnz %w0, 1b\n" \
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" dmb ish\n" \
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"3:\n" \
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" .pushsection .fixup,\"ax\"\n" \
···
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static inline int
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arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr)
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{
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-
int oldval = 0, ret, tmp;
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+
int oldval, ret, tmp;
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u32 __user *uaddr = __uaccess_mask_ptr(_uaddr);
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pagefault_disable();
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switch (op) {
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case FUTEX_OP_SET:
60
-
__futex_atomic_op("mov %w0, %w4",
60
+
__futex_atomic_op("mov %w3, %w4",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_ADD:
64
-
__futex_atomic_op("add %w0, %w1, %w4",
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+
__futex_atomic_op("add %w3, %w1, %w4",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_OR:
68
-
__futex_atomic_op("orr %w0, %w1, %w4",
68
+
__futex_atomic_op("orr %w3, %w1, %w4",
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ret, oldval, uaddr, tmp, oparg);
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break;
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case FUTEX_OP_ANDN:
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-
__futex_atomic_op("and %w0, %w1, %w4",
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+
__futex_atomic_op("and %w3, %w1, %w4",
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ret, oldval, uaddr, tmp, ~oparg);
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break;
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case FUTEX_OP_XOR:
76
-
__futex_atomic_op("eor %w0, %w1, %w4",
76
+
__futex_atomic_op("eor %w3, %w1, %w4",
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ret, oldval, uaddr, tmp, oparg);
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break;
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default:
+5
arch/arm64/include/asm/module.h
+5
arch/arm64/include/asm/module.h
···
73
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struct plt_entry get_plt_entry(u64 dst, void *pc);
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bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b);
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+
static inline bool plt_entry_is_initialized(const struct plt_entry *e)
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+
{
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+
return e->adrp || e->add || e->br;
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+
}
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+
76
81
#endif /* __ASM_MODULE_H */
+1
-2
arch/arm64/kernel/ftrace.c
+1
-2
arch/arm64/kernel/ftrace.c
···
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trampoline = get_plt_entry(addr, mod->arch.ftrace_trampoline);
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if (!plt_entries_equal(mod->arch.ftrace_trampoline,
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&trampoline)) {
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-
if (!plt_entries_equal(mod->arch.ftrace_trampoline,
111
-
&(struct plt_entry){})) {
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+
if (plt_entry_is_initialized(mod->arch.ftrace_trampoline)) {
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pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");
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return -EINVAL;
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113
}
+9
-6
arch/arm64/kernel/traps.c
+9
-6
arch/arm64/kernel/traps.c
···
102
102
void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
103
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{
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104
struct stackframe frame;
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-
int skip;
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+
int skip = 0;
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pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
108
+
109
+
if (regs) {
110
+
if (user_mode(regs))
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+
return;
112
+
skip = 1;
113
+
}
108
114
109
115
if (!tsk)
110
116
tsk = current;
···
132
126
frame.graph = 0;
133
127
#endif
134
128
135
-
skip = !!regs;
136
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printk("Call trace:\n");
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do {
138
131
/* skip until specified stack frame */
···
181
176
return ret;
182
177
183
178
print_modules();
184
-
__show_regs(regs);
185
179
pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
186
180
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
187
181
end_of_stack(tsk));
182
+
show_regs(regs);
188
183
189
-
if (!user_mode(regs)) {
190
-
dump_backtrace(regs, tsk);
184
+
if (!user_mode(regs))
191
185
dump_instr(KERN_EMERG, regs);
192
-
}
193
186
194
187
return ret;
195
188
}