diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5b13a932561fc0bbf2fda570aa8b1dfa1d57b3a..fdcd54d39c1efcd789e7860b81d1033f2104f4b9 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1800,11 +1800,11 @@ config RANDOMIZE_BASE
If unsure, say N.
config RANDOMIZE_MODULE_REGION_FULL
- bool "Randomize the module region over a 4 GB range"
+ bool "Randomize the module region over a 2 GB range"
depends on RANDOMIZE_BASE
default y
help
- Randomizes the location of the module region inside a 4 GB window
+ Randomizes the location of the module region inside a 2 GB window
covering the core kernel. This way, it is less likely for modules
to leak information about the location of core kernel data structures
but it does imply that function calls between modules and the core
@@ -1812,7 +1812,10 @@ config RANDOMIZE_MODULE_REGION_FULL
When this option is not set, the module region will be randomized over
a limited range that contains the [_stext, _etext] interval of the
- core kernel, so branch relocations are always in range.
+ core kernel, so branch relocations are almost always in range unless
+ ARM64_MODULE_PLTS is enabled and the region is exhausted. In this
+ particular case of region exhaustion, modules might be able to fall
+ back to a larger 2GB area.
config CC_HAVE_STACKPROTECTOR_SYSREG
def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 7bc37d0a1b68b9d86fbdcc48e7b203021d6bd92a..7b668db432612941375bd315215e1195a1445513 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -21,19 +21,11 @@ LDFLAGS_vmlinux += -shared -Bsymbolic -z notext \
endif
ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
- ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
-$(warning ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum)
- else
+ ifeq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
LDFLAGS_vmlinux += --fix-cortex-a53-843419
endif
endif
-ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS), y)
- ifneq ($(CONFIG_ARM64_LSE_ATOMICS), y)
-$(warning LSE atomics not supported by binutils)
- endif
-endif
-
cc_has_k_constraint := $(call try-run,echo \
'int main(void) { \
asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \
@@ -176,6 +168,17 @@ vdso_install:
archprepare:
$(Q)$(MAKE) $(build)=arch/arm64/tools kapi
+ifeq ($(CONFIG_ARM64_ERRATUM_843419),y)
+ ifneq ($(CONFIG_ARM64_LD_HAS_FIX_ERRATUM_843419),y)
+ @echo "warning: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum" >&2
+ endif
+endif
+ifeq ($(CONFIG_ARM64_USE_LSE_ATOMICS),y)
+ ifneq ($(CONFIG_ARM64_LSE_ATOMICS),y)
+ @echo "warning: LSE atomics not supported by binutils" >&2
+ endif
+endif
+
# We use MRPROPER_FILES and CLEAN_FILES now
archclean:
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index e58bca832dfff2e89536e8daceeb23cae73d2160..41b332c054ab824cb041591e4e3eb639a1b82154 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -320,7 +320,17 @@ static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
static inline unsigned long regs_return_value(struct pt_regs *regs)
{
- return regs->regs[0];
+ unsigned long val = regs->regs[0];
+
+ /*
+ * Audit currently uses regs_return_value() instead of
+ * syscall_get_return_value(). Apply the same sign-extension here until
+ * audit is updated to use syscall_get_return_value().
+ */
+ if (compat_user_mode(regs))
+ val = sign_extend64(val, 31);
+
+ return val;
}
static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc)
diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h
index 1801399204d79fe011ec07e8653a3b7ca1bacdb3..8aebc00c17184836fd887c313a34ac2a29520a60 100644
--- a/arch/arm64/include/asm/stacktrace.h
+++ b/arch/arm64/include/asm/stacktrace.h
@@ -35,7 +35,7 @@ struct stack_info {
* accounting information necessary for robust unwinding.
*
* @fp: The fp value in the frame record (or the real fp)
- * @pc: The fp value in the frame record (or the real lr)
+ * @pc: The lr value in the frame record (or the real lr)
*
* @stacks_done: Stacks which have been entirely unwound, for which it is no
* longer valid to unwind to.
diff --git a/arch/arm64/include/asm/syscall.h b/arch/arm64/include/asm/syscall.h
index cfc0672013f672aaf77a18b1c2f3a7a5e692266e..03e20895453a7cc8c2f870e0c6312ae05559b714 100644
--- a/arch/arm64/include/asm/syscall.h
+++ b/arch/arm64/include/asm/syscall.h
@@ -29,22 +29,23 @@ static inline void syscall_rollback(struct task_struct *task,
regs->regs[0] = regs->orig_x0;
}
-
-static inline long syscall_get_error(struct task_struct *task,
- struct pt_regs *regs)
+static inline long syscall_get_return_value(struct task_struct *task,
+ struct pt_regs *regs)
{
- unsigned long error = regs->regs[0];
+ unsigned long val = regs->regs[0];
if (is_compat_thread(task_thread_info(task)))
- error = sign_extend64(error, 31);
+ val = sign_extend64(val, 31);
- return IS_ERR_VALUE(error) ? error : 0;
+ return val;
}
-static inline long syscall_get_return_value(struct task_struct *task,
- struct pt_regs *regs)
+static inline long syscall_get_error(struct task_struct *task,
+ struct pt_regs *regs)
{
- return regs->regs[0];
+ unsigned long error = syscall_get_return_value(task, regs);
+
+ return IS_ERR_VALUE(error) ? error : 0;
}
static inline void syscall_set_return_value(struct task_struct *task,
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index cfa2cfde3019d678e32241acd21416891dd74c0e..418b2bba1521b48078106861851ebbcbda8ea02a 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -162,7 +162,9 @@ u64 __init kaslr_early_init(void)
* a PAGE_SIZE multiple in the range [_etext - MODULES_VSIZE,
* _stext) . This guarantees that the resulting region still
* covers [_stext, _etext], and that all relative branches can
- * be resolved without veneers.
+ * be resolved without veneers unless this region is exhausted
+ * and we fall back to a larger 2GB window in module_alloc()
+ * when ARM64_MODULE_PLTS is enabled.
*/
module_range = MODULES_VSIZE - (u64)(_etext - _stext);
module_alloc_base = (u64)_etext + offset - MODULES_VSIZE;
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 499b6b2f9757f9ad198c655de743227f611c2562..b381a1ee9ea7f6e18941045043c64fe3fb276a2b 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1862,7 +1862,7 @@ void syscall_trace_exit(struct pt_regs *regs)
audit_syscall_exit(regs);
if (flags & _TIF_SYSCALL_TRACEPOINT)
- trace_sys_exit(regs, regs_return_value(regs));
+ trace_sys_exit(regs, syscall_get_return_value(current, regs));
if (flags & (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP))
tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index f8192f4ae0b8a0a9cbd21a7d0037940a263fa0b6..23036334f4dc4b7159279e40305447485d8deb69 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -29,6 +29,7 @@
#include <asm/unistd.h>
#include <asm/fpsimd.h>
#include <asm/ptrace.h>
+#include <asm/syscall.h>
#include <asm/signal32.h>
#include <asm/traps.h>
#include <asm/vdso.h>
@@ -890,7 +891,7 @@ static void do_signal(struct pt_regs *regs)
retval == -ERESTART_RESTARTBLOCK ||
(retval == -ERESTARTSYS &&
!(ksig.ka.sa.sa_flags & SA_RESTART)))) {
- regs->regs[0] = -EINTR;
+ syscall_set_return_value(current, regs, -EINTR, 0);
regs->pc = continue_addr;
}
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index b83c8d911930a8641155c84ae8dfaa400c5f04cc..8982a2b78acfcbe2b4459367d92d976ff31632f9 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -218,7 +218,7 @@ void show_stack(struct task_struct *tsk, unsigned long *sp, const char *loglvl)
#ifdef CONFIG_STACKTRACE
-noinline void arch_stack_walk(stack_trace_consume_fn consume_entry,
+noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
void *cookie, struct task_struct *task,
struct pt_regs *regs)
{
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 263d6c1a525f3d6d06c944917454d4178fc3515c..50a0f1a38e849ff16fa47ea460d8114803147443 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -54,10 +54,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno,
ret = do_ni_syscall(regs, scno);
}
- if (is_compat_task())
- ret = lower_32_bits(ret);
-
- regs->regs[0] = ret;
+ syscall_set_return_value(current, regs, 0, ret);
/*
* Ultimately, this value will get limited by KSTACK_OFFSET_MAX(),
@@ -115,7 +112,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
* syscall. do_notify_resume() will send a signal to userspace
* before the syscall is restarted.
*/
- regs->regs[0] = -ERESTARTNOINTR;
+ syscall_set_return_value(current, regs, -ERESTARTNOINTR, 0);
return;
}
@@ -136,7 +133,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
* anyway.
*/
if (scno == NO_SYSCALL)
- regs->regs[0] = -ENOSYS;
+ syscall_set_return_value(current, regs, -ENOSYS, 0);
scno = syscall_trace_enter(regs);
if (scno == NO_SYSCALL)
goto trace_exit;