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sparc: Support show_unhandled_signals.
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Just faults right now, will add other traps later.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Mar 1, 2010
1 parent c7ec2b5 commit 4b17764
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Showing 3 changed files with 92 additions and 50 deletions.
106 changes: 60 additions & 46 deletions arch/sparc/mm/fault_32.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,8 @@

extern int prom_node_root;

int show_unhandled_signals = 1;

/* At boot time we determine these two values necessary for setting
* up the segment maps and page table entries (pte's).
*/
Expand Down Expand Up @@ -149,6 +151,45 @@ asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
return 0;
}

static inline void
show_signal_msg(struct pt_regs *regs, int sig, int code,
unsigned long address, struct task_struct *tsk)
{
if (!unhandled_signal(tsk, sig))
return;

if (!printk_ratelimit())
return;

printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), address,
(void *)regs->pc, (void *)regs->u_regs[UREG_I7],
(void *)regs->u_regs[UREG_FP], code);

print_vma_addr(KERN_CONT " in ", regs->pc);

printk(KERN_CONT "\n");
}

static void __do_fault_siginfo(int code, int sig, struct pt_regs *regs,
unsigned long addr)
{
siginfo_t info;

info.si_signo = sig;
info.si_code = code;
info.si_errno = 0;
info.si_addr = (void __user *) addr;
info.si_trapno = 0;

if (unlikely(show_unhandled_signals))
show_signal_msg(regs, sig, info.si_code,
addr, current);

force_sig_info (sig, &info, current);
}

extern unsigned long safe_compute_effective_address(struct pt_regs *,
unsigned int);

Expand All @@ -168,6 +209,14 @@ static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
return safe_compute_effective_address(regs, insn);
}

static noinline void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
int text_fault)
{
unsigned long addr = compute_si_addr(regs, text_fault);

__do_fault_siginfo(code, sig, regs, addr);
}

asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
unsigned long address)
{
Expand All @@ -176,9 +225,8 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
struct mm_struct *mm = tsk->mm;
unsigned int fixup;
unsigned long g2;
siginfo_t info;
int from_user = !(regs->psr & PSR_PS);
int fault;
int fault, code;

if(text_fault)
address = regs->pc;
Expand All @@ -195,7 +243,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
if (!ARCH_SUN4C && address >= TASK_SIZE)
goto vmalloc_fault;

info.si_code = SEGV_MAPERR;
code = SEGV_MAPERR;

/*
* If we're in an interrupt or have no user
Expand Down Expand Up @@ -229,7 +277,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
* we can handle it..
*/
good_area:
info.si_code = SEGV_ACCERR;
code = SEGV_ACCERR;
if(write) {
if(!(vma->vm_flags & VM_WRITE))
goto bad_area;
Expand Down Expand Up @@ -273,18 +321,8 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,

bad_area_nosemaphore:
/* User mode accesses just cause a SIGSEGV */
if(from_user) {
#if 0
printk("Fault whee %s [%d]: segfaults at %08lx pc=%08lx\n",
tsk->comm, tsk->pid, address, regs->pc);
#endif
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code set above to make clear whether
this was a SEGV_MAPERR or SEGV_ACCERR fault. */
info.si_addr = (void __user *)compute_si_addr(regs, text_fault);
info.si_trapno = 0;
force_sig_info (SIGSEGV, &info, tsk);
if (from_user) {
do_fault_siginfo(code, SIGSEGV, regs, text_fault);
return;
}

Expand Down Expand Up @@ -335,12 +373,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,

do_sigbus:
up_read(&mm->mmap_sem);
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void __user *) compute_si_addr(regs, text_fault);
info.si_trapno = 0;
force_sig_info (SIGBUS, &info, tsk);
do_fault_siginfo(BUS_ADRERR, SIGBUS, regs, text_fault);
if (!from_user)
goto no_context;

Expand Down Expand Up @@ -466,14 +499,10 @@ static void force_user_fault(unsigned long address, int write)
struct vm_area_struct *vma;
struct task_struct *tsk = current;
struct mm_struct *mm = tsk->mm;
siginfo_t info;
int code;

info.si_code = SEGV_MAPERR;
code = SEGV_MAPERR;

#if 0
printk("wf<pid=%d,wr=%d,addr=%08lx>\n",
tsk->pid, write, address);
#endif
down_read(&mm->mmap_sem);
vma = find_vma(mm, address);
if(!vma)
Expand All @@ -485,7 +514,7 @@ static void force_user_fault(unsigned long address, int write)
if(expand_stack(vma, address))
goto bad_area;
good_area:
info.si_code = SEGV_ACCERR;
code = SEGV_ACCERR;
if(write) {
if(!(vma->vm_flags & VM_WRITE))
goto bad_area;
Expand All @@ -502,27 +531,12 @@ static void force_user_fault(unsigned long address, int write)
return;
bad_area:
up_read(&mm->mmap_sem);
#if 0
printk("Window whee %s [%d]: segfaults at %08lx\n",
tsk->comm, tsk->pid, address);
#endif
info.si_signo = SIGSEGV;
info.si_errno = 0;
/* info.si_code set above to make clear whether
this was a SEGV_MAPERR or SEGV_ACCERR fault. */
info.si_addr = (void __user *) address;
info.si_trapno = 0;
force_sig_info (SIGSEGV, &info, tsk);
__do_fault_siginfo(code, SIGSEGV, tsk->thread.kregs, address);
return;

do_sigbus:
up_read(&mm->mmap_sem);
info.si_signo = SIGBUS;
info.si_errno = 0;
info.si_code = BUS_ADRERR;
info.si_addr = (void __user *) address;
info.si_trapno = 0;
force_sig_info (SIGBUS, &info, tsk);
__do_fault_siginfo(BUS_ADRERR, SIGBUS, tsk->thread.kregs, address);
}

void window_overflow_fault(void)
Expand Down
34 changes: 31 additions & 3 deletions arch/sparc/mm/fault_64.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,8 @@
#include <asm/sections.h>
#include <asm/mmu_context.h>

int show_unhandled_signals = 1;

static inline __kprobes int notify_page_fault(struct pt_regs *regs)
{
int ret = 0;
Expand Down Expand Up @@ -128,22 +130,48 @@ static unsigned int get_user_insn(unsigned long tpc)
return insn;
}

static inline void
show_signal_msg(struct pt_regs *regs, int sig, int code,
unsigned long address, struct task_struct *tsk)
{
if (!unhandled_signal(tsk, sig))
return;

if (!printk_ratelimit())
return;

printk("%s%s[%d]: segfault at %lx ip %p (rpc %p) sp %p error %x",
task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
tsk->comm, task_pid_nr(tsk), address,
(void *)regs->tpc, (void *)regs->u_regs[UREG_I7],
(void *)regs->u_regs[UREG_FP], code);

print_vma_addr(KERN_CONT " in ", regs->tpc);

printk(KERN_CONT "\n");
}

extern unsigned long compute_effective_address(struct pt_regs *, unsigned int, unsigned int);

static void do_fault_siginfo(int code, int sig, struct pt_regs *regs,
unsigned int insn, int fault_code)
{
unsigned long addr;
siginfo_t info;

info.si_code = code;
info.si_signo = sig;
info.si_errno = 0;
if (fault_code & FAULT_CODE_ITLB)
info.si_addr = (void __user *) regs->tpc;
addr = regs->tpc;
else
info.si_addr = (void __user *)
compute_effective_address(regs, insn, 0);
addr = compute_effective_address(regs, insn, 0);
info.si_addr = (void __user *) addr;
info.si_trapno = 0;

if (unlikely(show_unhandled_signals))
show_signal_msg(regs, sig, code, addr, current);

force_sig_info(sig, &info, current);
}

Expand Down
2 changes: 1 addition & 1 deletion kernel/sysctl.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1441,7 +1441,7 @@ static struct ctl_table fs_table[] = {
};

static struct ctl_table debug_table[] = {
#if defined(CONFIG_X86) || defined(CONFIG_PPC)
#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
{
.procname = "exception-trace",
.data = &show_unhandled_signals,
Expand Down

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