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author | Jiri Kosina <jkosina@suse.cz> | 2010-12-22 18:57:02 +0100 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-12-22 18:57:02 +0100 |
commit | 4b7bd364700d9ac8372eff48832062b936d0793b (patch) | |
tree | 0dbf78c95456a0b02d07fcd473281f04a87e266d /arch/s390/kernel/kprobes.c | |
parent | anon_inodes: fix wrong function name in comment (diff) | |
parent | Linux 2.6.37-rc7 (diff) | |
download | linux-4b7bd364700d9ac8372eff48832062b936d0793b.tar.xz linux-4b7bd364700d9ac8372eff48832062b936d0793b.zip |
Merge branch 'master' into for-next
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
Diffstat (limited to 'arch/s390/kernel/kprobes.c')
-rw-r--r-- | arch/s390/kernel/kprobes.c | 70 |
1 files changed, 53 insertions, 17 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index d60fc4398516..2564793ec2b6 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -30,6 +30,7 @@ #include <asm/sections.h> #include <linux/module.h> #include <linux/slab.h> +#include <linux/hardirq.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); @@ -212,7 +213,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) /* Set the PER control regs, turns on single step for this address */ __ctl_load(kprobe_per_regs, 9, 11); regs->psw.mask |= PSW_MASK_PER; - regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK); + regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT); } static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) @@ -239,7 +240,7 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, __get_cpu_var(current_kprobe) = p; /* Save the interrupt and per flags */ kcb->kprobe_saved_imask = regs->psw.mask & - (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK); + (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT); /* Save the control regs that govern PER */ __ctl_store(kcb->kprobe_saved_ctl, 9, 11); } @@ -316,8 +317,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) return 1; ss_probe: - if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO)) - local_irq_disable(); prepare_singlestep(p, regs); kcb->kprobe_status = KPROBE_HIT_SS; return 1; @@ -350,6 +349,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, struct hlist_node *node, *tmp; unsigned long flags, orig_ret_address = 0; unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; + kprobe_opcode_t *correct_ret_addr = NULL; INIT_HLIST_HEAD(&empty_rp); kretprobe_hash_lock(current, &head, &flags); @@ -372,10 +372,32 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, /* another task is sharing our hash bucket */ continue; - if (ri->rp && ri->rp->handler) - ri->rp->handler(ri, regs); + orig_ret_address = (unsigned long)ri->ret_addr; + + if (orig_ret_address != trampoline_address) + /* + * This is the real return address. Any other + * instances associated with this task are for + * other calls deeper on the call stack + */ + break; + } + + kretprobe_assert(ri, orig_ret_address, trampoline_address); + + correct_ret_addr = ri->ret_addr; + hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { + if (ri->task != current) + /* another task is sharing our hash bucket */ + continue; orig_ret_address = (unsigned long)ri->ret_addr; + + if (ri->rp && ri->rp->handler) { + ri->ret_addr = correct_ret_addr; + ri->rp->handler(ri, regs); + } + recycle_rp_inst(ri, &empty_rp); if (orig_ret_address != trampoline_address) { @@ -387,7 +409,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, break; } } - kretprobe_assert(ri, orig_ret_address, trampoline_address); + regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE; reset_current_kprobe(); @@ -465,8 +487,6 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) goto out; } reset_current_kprobe(); - if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO)) - local_irq_enable(); out: preempt_enable_no_resched(); @@ -482,7 +502,7 @@ out: return 1; } -int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) +static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -508,8 +528,6 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) restore_previous_kprobe(kcb); else { reset_current_kprobe(); - if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO)) - local_irq_enable(); } preempt_enable_no_resched(); break; @@ -553,6 +571,18 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) return 0; } +int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) +{ + int ret; + + if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT)) + local_irq_disable(); + ret = kprobe_trap_handler(regs, trapnr); + if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT)) + local_irq_restore(regs->psw.mask & ~PSW_MASK_PER); + return ret; +} + /* * Wrapper routine to for handling exceptions. */ @@ -560,8 +590,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { struct die_args *args = (struct die_args *)data; + struct pt_regs *regs = args->regs; int ret = NOTIFY_DONE; + if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT)) + local_irq_disable(); + switch (val) { case DIE_BPT: if (kprobe_handler(args->regs)) @@ -572,16 +606,17 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, ret = NOTIFY_STOP; break; case DIE_TRAP: - /* kprobe_running() needs smp_processor_id() */ - preempt_disable(); - if (kprobe_running() && - kprobe_fault_handler(args->regs, args->trapnr)) + if (!preemptible() && kprobe_running() && + kprobe_trap_handler(args->regs, args->trapnr)) ret = NOTIFY_STOP; - preempt_enable(); break; default: break; } + + if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT)) + local_irq_restore(regs->psw.mask & ~PSW_MASK_PER); + return ret; } @@ -595,6 +630,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs) /* setup return addr to the jprobe handler routine */ regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE; + regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT); /* r14 is the function return address */ kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14]; |