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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-03-01 12:02:44 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-03-06 11:41:54 +0100 |
| commit | c6986f16a7022ccfb73d91bc7676c8e1d15e5342 (patch) | |
| tree | 315d164b674c90d94ceaaf55b7753a91e37a667d | |
| parent | e586edcb410543768ef009eaa22a2d9dd4a53846 (diff) | |
| download | focaccia-qemu-c6986f16a7022ccfb73d91bc7676c8e1d15e5342.tar.gz focaccia-qemu-c6986f16a7022ccfb73d91bc7676c8e1d15e5342.zip | |
KVM: x86: do not fail if software breakpoint has already been removed
If kvm_arch_remove_sw_breakpoint finds that a software breakpoint does not have an INT3 instruction, it fails. This can happen if one sets a software breakpoint in a kernel module and then reloads it. gdb then thinks the breakpoint cannot be deleted and there is no way to add it back. Suggested-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | target/i386/kvm/kvm.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 0b5755e42b..c8d61daf68 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -4352,8 +4352,13 @@ int kvm_arch_remove_sw_breakpoint(CPUState *cs, struct kvm_sw_breakpoint *bp) { uint8_t int3; - if (cpu_memory_rw_debug(cs, bp->pc, &int3, 1, 0) || int3 != 0xcc || - cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 1, 1)) { + if (cpu_memory_rw_debug(cs, bp->pc, &int3, 1, 0)) { + return -EINVAL; + } + if (int3 != 0xcc) { + return 0; + } + if (cpu_memory_rw_debug(cs, bp->pc, (uint8_t *)&bp->saved_insn, 1, 1)) { return -EINVAL; } return 0; |