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| author | Helge Deller <deller@gmx.de> | 2014-05-05 18:07:12 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2014-05-15 21:12:15 +0200 |
| commit | fef47e2a2e1e75fe50a10f634a80f16808348cc6 (patch) | |
| tree | f052abbf816238548d278d20cd8164daa7cd4dcc /arch/parisc/mm | |
| parent | 455c6fdbd219161bd09b1165f11699d6d73de11c (diff) | |
| download | linux-fef47e2a2e1e75fe50a10f634a80f16808348cc6.tar.bz2 | |
parisc: ratelimit userspace segfault printing
Ratelimit printing of userspace segfaults and make it runtime
configurable via the /proc/sys/debug/exception-trace variable. This
should resolve syslog from growing way too fast and thus prevents
possible system service attacks.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 3.13+
Diffstat (limited to 'arch/parisc/mm')
| -rw-r--r-- | arch/parisc/mm/fault.c | 44 |
1 files changed, 30 insertions, 14 deletions
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c index 9d08c71a967e..d72197f0ddb8 100644 --- a/arch/parisc/mm/fault.c +++ b/arch/parisc/mm/fault.c @@ -19,10 +19,6 @@ #include <asm/uaccess.h> #include <asm/traps.h> -#define PRINT_USER_FAULTS /* (turn this on if you want user faults to be */ - /* dumped to the console via printk) */ - - /* Various important other fields */ #define bit22set(x) (x & 0x00000200) #define bits23_25set(x) (x & 0x000001c0) @@ -34,6 +30,8 @@ DEFINE_PER_CPU(struct exception_data, exception_data); +int show_unhandled_signals = 1; + /* * parisc_acctyp(unsigned int inst) -- * Given a PA-RISC memory access instruction, determine if the @@ -173,6 +171,32 @@ int fixup_exception(struct pt_regs *regs) return 0; } +/* + * Print out info about fatal segfaults, if the show_unhandled_signals + * sysctl is set: + */ +static inline void +show_signal_msg(struct pt_regs *regs, unsigned long code, + unsigned long address, struct task_struct *tsk, + struct vm_area_struct *vma) +{ + if (!unhandled_signal(tsk, SIGSEGV)) + return; + + if (!printk_ratelimit()) + return; + + pr_warn("\n"); + pr_warn("do_page_fault() command='%s' type=%lu address=0x%08lx", + tsk->comm, code, address); + print_vma_addr(KERN_CONT " in ", regs->iaoq[0]); + if (vma) + pr_warn(" vm_start = 0x%08lx, vm_end = 0x%08lx\n", + vma->vm_start, vma->vm_end); + + show_regs(regs); +} + void do_page_fault(struct pt_regs *regs, unsigned long code, unsigned long address) { @@ -270,16 +294,8 @@ bad_area: if (user_mode(regs)) { struct siginfo si; -#ifdef PRINT_USER_FAULTS - printk(KERN_DEBUG "\n"); - printk(KERN_DEBUG "do_page_fault() pid=%d command='%s' type=%lu address=0x%08lx\n", - task_pid_nr(tsk), tsk->comm, code, address); - if (vma) { - printk(KERN_DEBUG "vm_start = 0x%08lx, vm_end = 0x%08lx\n", - vma->vm_start, vma->vm_end); - } - show_regs(regs); -#endif + show_signal_msg(regs, code, address, tsk, vma); + switch (code) { case 15: /* Data TLB miss fault/Data page fault */ /* send SIGSEGV when outside of vma */ |