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author | android-build-team Robot <android-build-team-robot@google.com> | 2017-08-15 07:53:22 +0000 |
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committer | android-build-team Robot <android-build-team-robot@google.com> | 2017-08-15 07:53:22 +0000 |
commit | c46479e146062205f7bf1f1d73d9dde277251cf2 (patch) | |
tree | 126ac23af01755de160adac30e27157781e5bb9a /arch/arm64/kernel/process.c | |
parent | 2684a6c505531426bb7d4c8a68aab91abe6af05c (diff) | |
parent | fbc4ea9a080b1523a6e77562645d9d79c6368a25 (diff) | |
download | v4.4-nougat-iot-release.tar.gz |
release-request-65fa9893-af48-4e1d-bbfd-0ad00ce88026-for-git_nyc-iot-release-4273224 snap-temp-L21600000093073568android-n-iot-release-smart-display-r2android-n-iot-release-smart-displayandroid-n-iot-release-polk-at1android-n-iot-release-lg-thinq-wk7android-n-iot-release-ihome-igv1nougat-iot-release
Change-Id: I9624021a4a6df994f06c0dcbee05ce5a15a11cfa
Diffstat (limited to 'arch/arm64/kernel/process.c')
-rw-r--r-- | arch/arm64/kernel/process.c | 42 |
1 files changed, 36 insertions, 6 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index e6afea67f6c1..e34bcf3f2c35 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -45,6 +45,9 @@ #include <linux/personality.h> #include <linux/notifier.h> #include <trace/events/power.h> +#ifdef CONFIG_THREAD_INFO_IN_TASK +#include <linux/percpu.h> +#endif #include <asm/alternative.h> #include <asm/compat.h> @@ -390,6 +393,22 @@ void uao_thread_switch(struct task_struct *next) } } +#ifdef CONFIG_THREAD_INFO_IN_TASK +/* + * We store our current task in sp_el0, which is clobbered by userspace. Keep a + * shadow copy so that we can restore this upon entry from userspace. + * + * This is *only* for exception entry from EL0, and is not valid until we + * __switch_to() a user task. + */ +DEFINE_PER_CPU(struct task_struct *, __entry_task); + +static void entry_task_switch(struct task_struct *next) +{ + __this_cpu_write(__entry_task, next); +} +#endif + /* * Thread switching. */ @@ -402,6 +421,9 @@ struct task_struct *__switch_to(struct task_struct *prev, tls_thread_switch(next); hw_breakpoint_thread_switch(next); contextidr_thread_switch(next); +#ifdef CONFIG_THREAD_INFO_IN_TASK + entry_task_switch(next); +#endif uao_thread_switch(next); /* @@ -419,27 +441,35 @@ struct task_struct *__switch_to(struct task_struct *prev, unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; - unsigned long stack_page; + unsigned long stack_page, ret = 0; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; + stack_page = (unsigned long)try_get_task_stack(p); + if (!stack_page) + return 0; + frame.fp = thread_saved_fp(p); frame.sp = thread_saved_sp(p); frame.pc = thread_saved_pc(p); #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame.graph = p->curr_ret_stack; #endif - stack_page = (unsigned long)task_stack_page(p); do { if (frame.sp < stack_page || frame.sp >= stack_page + THREAD_SIZE || unwind_frame(p, &frame)) - return 0; - if (!in_sched_functions(frame.pc)) - return frame.pc; + goto out; + if (!in_sched_functions(frame.pc)) { + ret = frame.pc; + goto out; + } } while (count ++ < 16); - return 0; + +out: + put_task_stack(p); + return ret; } unsigned long arch_align_stack(unsigned long sp) |