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authorOleg Nesterov <oleg@redhat.com>2012-06-15 17:43:31 +0200
committerIngo Molnar <mingo@kernel.org>2012-06-16 09:10:43 +0200
commitc1914a0936f79ed0236f670122e06e36e4d332ee (patch)
tree965d8c31ffb45b57d83cf999cbc257ec724a5d47 /kernel/events
parent5323ce71e4b4e1f188ebbc0cc7776885ea6c75fb (diff)
uprobes: Install_breakpoint() should fail if is_swbp_insn() == T
install_breakpoint() returns -EEXIST if is_swbp_insn(orig_insn) == T, the caller treats this code as success. This is doubly wrong. The successful return should set UPROBE_COPY_INSN, but the real problem is that it shouldn't succeed. If the probed insn is int3 the application should get SIGTRAP, this won't happen with uprobe. Probably we can fix this, we can add the UPROBE_SHARED_BP flag and teach handle_swbp/set_orig_insn to handle this case correctly. But this needs some complications and we have other insns which can't be probed, lets make a simple fix for now. I think this needs a cleanup. UPROBE_COPY_INSN should die, copy_insn() should be called by alloc_uprobe(). arch_uprobe_analyze_insn() depends on ->mm (ia32_compat) but it is called only once. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20120615154331.GA9578@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/uprobes.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 3ccdb29ee8d..ec78152e32e 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -693,7 +693,7 @@ install_breakpoint(struct uprobe *uprobe, struct mm_struct *mm,
return ret;
if (is_swbp_insn((uprobe_opcode_t *)uprobe->arch.insn))
- return -EEXIST;
+ return -ENOTSUPP;
ret = arch_uprobe_analyze_insn(&uprobe->arch, mm, addr);
if (ret)