summaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-04-13 08:57:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-04-13 08:57:00 -0700
commit5ded88718aef7e92a9806f6ff4b89c7f2a4f1570 (patch)
treea6fcf73123205891b848221eb63b10e051500d65 /arch
parent6d0a598489ca687e1ebac37eef546526eca41347 (diff)
parent045afc24124d80c6998d9c770844c67912083506 (diff)
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
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/futex.h16
-rw-r--r--arch/arm64/include/asm/module.h5
-rw-r--r--arch/arm64/kernel/ftrace.c3
-rw-r--r--arch/arm64/kernel/traps.c15
4 files changed, 23 insertions, 16 deletions
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index cccb83ad7fa8..e1d95f08f8e1 100644
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -30,8 +30,8 @@ do { \
" prfm pstl1strm, %2\n" \
"1: ldxr %w1, %2\n" \
insn "\n" \
-"2: stlxr %w3, %w0, %2\n" \
-" cbnz %w3, 1b\n" \
+"2: stlxr %w0, %w3, %2\n" \
+" cbnz %w0, 1b\n" \
" dmb ish\n" \
"3:\n" \
" .pushsection .fixup,\"ax\"\n" \
@@ -50,30 +50,30 @@ do { \
static inline int
arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr)
{
- int oldval = 0, ret, tmp;
+ int oldval, ret, tmp;
u32 __user *uaddr = __uaccess_mask_ptr(_uaddr);
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
- __futex_atomic_op("mov %w0, %w4",
+ __futex_atomic_op("mov %w3, %w4",
ret, oldval, uaddr, tmp, oparg);
break;
case FUTEX_OP_ADD:
- __futex_atomic_op("add %w0, %w1, %w4",
+ __futex_atomic_op("add %w3, %w1, %w4",
ret, oldval, uaddr, tmp, oparg);
break;
case FUTEX_OP_OR:
- __futex_atomic_op("orr %w0, %w1, %w4",
+ __futex_atomic_op("orr %w3, %w1, %w4",
ret, oldval, uaddr, tmp, oparg);
break;
case FUTEX_OP_ANDN:
- __futex_atomic_op("and %w0, %w1, %w4",
+ __futex_atomic_op("and %w3, %w1, %w4",
ret, oldval, uaddr, tmp, ~oparg);
break;
case FUTEX_OP_XOR:
- __futex_atomic_op("eor %w0, %w1, %w4",
+ __futex_atomic_op("eor %w3, %w1, %w4",
ret, oldval, uaddr, tmp, oparg);
break;
default:
diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h
index 905e1bb0e7bd..cd9f4e9d04d3 100644
--- a/arch/arm64/include/asm/module.h
+++ b/arch/arm64/include/asm/module.h
@@ -73,4 +73,9 @@ static inline bool is_forbidden_offset_for_adrp(void *place)
struct plt_entry get_plt_entry(u64 dst, void *pc);
bool plt_entries_equal(const struct plt_entry *a, const struct plt_entry *b);
+static inline bool plt_entry_is_initialized(const struct plt_entry *e)
+{
+ return e->adrp || e->add || e->br;
+}
+
#endif /* __ASM_MODULE_H */
diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c
index 8e4431a8821f..07b298120182 100644
--- a/arch/arm64/kernel/ftrace.c
+++ b/arch/arm64/kernel/ftrace.c
@@ -107,8 +107,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
trampoline = get_plt_entry(addr, mod->arch.ftrace_trampoline);
if (!plt_entries_equal(mod->arch.ftrace_trampoline,
&trampoline)) {
- if (!plt_entries_equal(mod->arch.ftrace_trampoline,
- &(struct plt_entry){})) {
+ if (plt_entry_is_initialized(mod->arch.ftrace_trampoline)) {
pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");
return -EINVAL;
}
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 8ad119c3f665..29755989f616 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -102,10 +102,16 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
struct stackframe frame;
- int skip;
+ int skip = 0;
pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
+ if (regs) {
+ if (user_mode(regs))
+ return;
+ skip = 1;
+ }
+
if (!tsk)
tsk = current;
@@ -126,7 +132,6 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
frame.graph = 0;
#endif
- skip = !!regs;
printk("Call trace:\n");
do {
/* skip until specified stack frame */
@@ -176,15 +181,13 @@ static int __die(const char *str, int err, struct pt_regs *regs)
return ret;
print_modules();
- __show_regs(regs);
pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk),
end_of_stack(tsk));
+ show_regs(regs);
- if (!user_mode(regs)) {
- dump_backtrace(regs, tsk);
+ if (!user_mode(regs))
dump_instr(KERN_EMERG, regs);
- }
return ret;
}