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f088258966
- relbranch_fixup(), for non-branches, would end up setting
regs->tnpc incorrectly, in fact it would set it equal to
regs->tpc which would cause that instruction to execute twice
Also, if this is not a PC-relative branch, we should just
leave regs->tnpc as-is. This covers cases like 'jmpl' which
branch to absolute values.
- To be absolutely %100 safe, we need to flush the instruction
cache for all assignments to kprobe->ainsn.insn[], including
cases like add_aggr_kprobe()
- prev_kprobe's status field needs to be 'unsigned long' to match
the type of the value it is saving
- jprobes were totally broken:
= jprobe_return() can run in the stack frame of the jprobe handler,
or in an even deeper stack frame, thus we'll be in the wrong
register window than the one from the original probe state.
So unwind using 'restore' instructions, if necessary, right
before we do the jprobe_return() breakpoint trap.
= There is no reason to save/restore the register window saved
at %sp at jprobe trigger time. Those registers cannot be
modified by the jprobe handler. Also, this code was saving
and restoring "sizeof (struct sparc_stackf)" bytes. Depending
upon the caller, this could clobber unrelated stack frame
pieces if there is only a basic 128-byte register window
stored on the stack, without the argument save area.
So just saving and restoring struct pt_regs is sufficient.
= Kill the "jprobe_saved_esp", totally unused.
Also, delete "jprobe_saved_regs_location", with the stack frame
unwind now done explicitly by jprobe_return(), this check is
superfluous.
Signed-off-by: David S. Miller <davem@davemloft.net>
47 lines
1.2 KiB
C
47 lines
1.2 KiB
C
#ifndef _SPARC64_KPROBES_H
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#define _SPARC64_KPROBES_H
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#include <linux/types.h>
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#include <linux/percpu.h>
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typedef u32 kprobe_opcode_t;
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#define BREAKPOINT_INSTRUCTION 0x91d02070 /* ta 0x70 */
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#define BREAKPOINT_INSTRUCTION_2 0x91d02071 /* ta 0x71 */
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#define MAX_INSN_SIZE 2
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#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)pentry
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#define arch_remove_kprobe(p) do {} while (0)
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#define ARCH_INACTIVE_KPROBE_COUNT 0
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#define flush_insn_slot(p) \
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do { flushi(&(p)->ainsn.insn[0]); \
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flushi(&(p)->ainsn.insn[1]); \
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} while (0)
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/* Architecture specific copy of original instruction*/
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struct arch_specific_insn {
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/* copy of the original instruction */
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kprobe_opcode_t insn[MAX_INSN_SIZE];
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};
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struct prev_kprobe {
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struct kprobe *kp;
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unsigned long status;
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unsigned long orig_tnpc;
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unsigned long orig_tstate_pil;
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};
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/* per-cpu kprobe control block */
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struct kprobe_ctlblk {
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unsigned long kprobe_status;
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unsigned long kprobe_orig_tnpc;
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unsigned long kprobe_orig_tstate_pil;
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struct pt_regs jprobe_saved_regs;
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struct prev_kprobe prev_kprobe;
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};
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extern int kprobe_exceptions_notify(struct notifier_block *self,
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unsigned long val, void *data);
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#endif /* _SPARC64_KPROBES_H */
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