1 files changed, 39 insertions, 13 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 6bee29097a56..80b9e070c207 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -42,10 +42,14 @@
 #include <asm/tlbdebug.h>
 #include <asm/traps.h>
 #include <asm/uaccess.h>
+#include <asm/watch.h>
 #include <asm/mmu_context.h>
 #include <asm/types.h>
 #include <asm/stacktrace.h>
 
+extern void check_wait(void);
+extern asmlinkage void r4k_wait(void);
+extern asmlinkage void rollback_handle_int(void);
 extern asmlinkage void handle_int(void);
 extern asmlinkage void handle_tlbm(void);
 extern asmlinkage void handle_tlbl(void);
@@ -822,8 +826,10 @@ static void mt_ase_fp_affinity(void)
                 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
                         cpumask_t tmask;
 
-                        cpus_and(tmask, current->thread.user_cpus_allowed,
-                                 mt_fpu_cpumask);
+                        current->thread.user_cpus_allowed
+                                = current->cpus_allowed;
+                        cpus_and(tmask, current->cpus_allowed,
+                                mt_fpu_cpumask);
                         set_cpus_allowed(current, tmask);
                         set_thread_flag(TIF_FPUBOUND);
                 }
@@ -907,13 +913,26 @@ asmlinkage void do_mdmx(struct pt_regs *regs)
 
 asmlinkage void do_watch(struct pt_regs *regs)
 {
+        u32 cause;
+
         /*
-         * We use the watch exception where available to detect stack
-         * overflows.
+         * Clear WP (bit 22) bit of cause register so we don't loop
+         * forever.
          */
-        dump_tlb_all();
-        show_regs(regs);
-        panic("Caught WATCH exception - probably caused by stack overflow.");
+        cause = read_c0_cause();
+        cause &= ~(1 << 22);
+        write_c0_cause(cause);
+
+        /*
+         * If the current thread has the watch registers loaded, save
+         * their values and send SIGTRAP.  Otherwise another thread
+         * left the registers set, clear them and continue.
+         */
+        if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
+                mips_read_watch_registers();
+                force_sig(SIGTRAP, current);
+        } else
+                mips_clear_watch_registers();
 }
 
 asmlinkage void do_mcheck(struct pt_regs *regs)
@@ -1251,6 +1270,9 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
 
                 extern char except_vec_vi, except_vec_vi_lui;
                 extern char except_vec_vi_ori, except_vec_vi_end;
+                extern char rollback_except_vec_vi;
+                char *vec_start = (cpu_wait == r4k_wait) ?
+                        &rollback_except_vec_vi : &except_vec_vi;
 #ifdef CONFIG_MIPS_MT_SMTC
                 /*
                  * We need to provide the SMTC vectored interrupt handler
@@ -1258,11 +1280,11 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
                  * Status.IM bit to be masked before going there.
                  */
                 extern char except_vec_vi_mori;
-                const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
+                const int mori_offset = &except_vec_vi_mori - vec_start;
 #endif /* CONFIG_MIPS_MT_SMTC */
-                const int handler_len = &except_vec_vi_end - &except_vec_vi;
-                const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
-                const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
+                const int handler_len = &except_vec_vi_end - vec_start;
+                const int lui_offset = &except_vec_vi_lui - vec_start;
+                const int ori_offset = &except_vec_vi_ori - vec_start;
 
                 if (handler_len > VECTORSPACING) {
                         /*
@@ -1272,7 +1294,7 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
                         panic("VECTORSPACING too small");
                 }
 
-                memcpy(b, &except_vec_vi, handler_len);
+                memcpy(b, vec_start, handler_len);
 #ifdef CONFIG_MIPS_MT_SMTC
                 BUG_ON(n > 7);  /* Vector index %d exceeds SMTC maximum. */
 
@@ -1554,6 +1576,10 @@ void __init trap_init(void)
         extern char except_vec3_generic, except_vec3_r4000;
         extern char except_vec4;
         unsigned long i;
+        int rollback;
+
+        check_wait();
+        rollback = (cpu_wait == r4k_wait);
 
 #if defined(CONFIG_KGDB)
         if (kgdb_early_setup)
@@ -1618,7 +1644,7 @@ void __init trap_init(void)
         if (board_be_init)
                 board_be_init();
 
-        set_except_vector(0, handle_int);
+        set_except_vector(0, rollback ? rollback_handle_int : handle_int);
         set_except_vector(1, handle_tlbm);
         set_except_vector(2, handle_tlbl);
         set_except_vector(3, handle_tlbs);