From 68d64569ff9568752eee68ee2fceaf68725834e9 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 1 Mar 2016 22:19:36 +0000 Subject: MIPS: Fix watchpoint restoration commit a7e89326b415b5d81c4b1016fd4a40db861eb58d upstream. Commit f51246efee2b ("MIPS: Get rid of finish_arch_switch().") moved the __restore_watch() call from finish_arch_switch() (i.e. after resume() returns) to before the resume() call in switch_to(). This results in watchpoints only being restored when a task is descheduled, preventing the watchpoints from being effective most of the time, except due to chance before the watchpoints are lazily removed. Fix the call sequence from switch_to() through to mips_install_watch_registers() to pass the task_struct pointer of the next task, instead of using current. This allows the watchpoints for the next (non-current) task to be restored without reintroducing finish_arch_switch(). Fixes: f51246efee2b ("MIPS: Get rid of finish_arch_switch().") Signed-off-by: James Hogan Cc: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12726/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/pm.c | 2 +- arch/mips/kernel/watch.c | 5 ++--- 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/mips/kernel') diff --git a/arch/mips/kernel/pm.c b/arch/mips/kernel/pm.c index fefdf39d3df3..dc814892133c 100644 --- a/arch/mips/kernel/pm.c +++ b/arch/mips/kernel/pm.c @@ -56,7 +56,7 @@ static void mips_cpu_restore(void) write_c0_userlocal(current_thread_info()->tp_value); /* Restore watch registers */ - __restore_watch(); + __restore_watch(current); } /** diff --git a/arch/mips/kernel/watch.c b/arch/mips/kernel/watch.c index 2a03abb5bd2c..9b78e375118e 100644 --- a/arch/mips/kernel/watch.c +++ b/arch/mips/kernel/watch.c @@ -15,10 +15,9 @@ * Install the watch registers for the current thread. A maximum of * four registers are installed although the machine may have more. */ -void mips_install_watch_registers(void) +void mips_install_watch_registers(struct task_struct *t) { - struct mips3264_watch_reg_state *watches = - ¤t->thread.watch.mips3264; + struct mips3264_watch_reg_state *watches = &t->thread.watch.mips3264; switch (current_cpu_data.watch_reg_use_cnt) { default: BUG(); -- cgit v1.2.3