x86, dumpstack: let signr=0 signal no do_exit

Change oops_end such that signr=0 signals that do_exit
is not to be called.

Currently, each use of __die is soon followed by a call
to oops_end and 'regs' is set to NULL if oops_end is expected
not to call do_exit. Change all such pairs to set signr=0
instead. On x86_64 oops_end is used 'bare' in die_nmi; use
signr=0 instead of regs=NULL there, too.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index 5493d31be4e5a3d73633065b63bc31fd1f2e40e1..7c22f99f0efb6fe7bfe628602d7d55f2c13e15f0 100644 (file)
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -318,7 +318,7 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
        __raw_spin_unlock(&die_lock);
        raw_local_irq_restore(flags);
 
-       if (!regs)
+       if (!signr)
                return;
 
        if (in_interrupt())
@@ -371,17 +371,18 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 void die(const char *str, struct pt_regs *regs, long err)
 {
        unsigned long flags = oops_begin();
+       int sig = SIGSEGV;
 
        if (die_nest_count < 3) {
                report_bug(regs->ip, regs);
 
                if (__die(str, regs, err))
-                       regs = NULL;
+                       sig = 0;
        } else {
                printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
        }
 
-       oops_end(flags, regs, SIGSEGV);
+       oops_end(flags, regs, sig);
 }
 
 static DEFINE_SPINLOCK(nmi_print_lock);

diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 96a5db7da8a747e5192f410c60fe9494e8d8e8d1..ffefea611ba38221b18d154e2c19f25dab729af2 100644 (file)
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -465,7 +465,7 @@ void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
                /* Nest count reaches zero, release the lock. */
                __raw_spin_unlock(&die_lock);
        raw_local_irq_restore(flags);
-       if (!regs) {
+       if (!signr) {
                oops_exit();
                return;
        }
@@ -509,13 +509,14 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 void die(const char *str, struct pt_regs *regs, long err)
 {
        unsigned long flags = oops_begin();
+       int sig = SIGSEGV;
 
        if (!user_mode(regs))
                report_bug(regs->ip, regs);
 
        if (__die(str, regs, err))
-               regs = NULL;
-       oops_end(flags, regs, SIGSEGV);
+               sig = 0;
+       oops_end(flags, regs, sig);
 }
 
 notrace __kprobes void
@@ -539,7 +540,7 @@ die_nmi(char *str, struct pt_regs *regs, int do_panic)
                crash_kexec(regs);
        if (do_panic || panic_on_oops)
                panic("Non maskable interrupt");
-       oops_end(flags, NULL, SIGBUS);
+       oops_end(flags, regs, 0);
        nmi_exit();
        local_irq_enable();
        do_exit(SIGBUS);

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 31e8730fa2463214f36c2f6b3df9d0f75f6be346..20ef272c412cc9ca113b0caaab17121626c1486f 100644 (file)
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -413,6 +413,7 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
                                 unsigned long error_code)
 {
        unsigned long flags = oops_begin();
+       int sig = SIGKILL;
        struct task_struct *tsk;
 
        printk(KERN_ALERT "%s: Corrupted page table at address %lx\n",
@@ -423,8 +424,8 @@ static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs,
        tsk->thread.trap_no = 14;
        tsk->thread.error_code = error_code;
        if (__die("Bad pagetable", regs, error_code))
-               regs = NULL;
-       oops_end(flags, regs, SIGKILL);
+               sig = 0;
+       oops_end(flags, regs, sig);
 }
 #endif
 
@@ -590,6 +591,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
        int fault;
 #ifdef CONFIG_X86_64
        unsigned long flags;
+       int sig;
 #endif
 
        tsk = current;
@@ -849,11 +851,12 @@ no_context:
        bust_spinlocks(0);
        do_exit(SIGKILL);
 #else
+       sig = SIGKILL;
        if (__die("Oops", regs, error_code))
-               regs = NULL;
+               sig = 0;
        /* Executive summary in case the body of the oops scrolled away */
        printk(KERN_EMERG "CR2: %016lx\n", address);
-       oops_end(flags, regs, SIGKILL);
+       oops_end(flags, regs, sig);
 #endif
 
 /*