Messages in this thread | | | Date | Sat, 25 Sep 2021 13:39:44 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v4] x86/insn, tools/x86: Fix some potential undefined behavior. |
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On Fri, 24 Sep 2021 16:02:33 -0300 Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> Em Thu, Sep 23, 2021 at 09:18:43AM -0700, Ian Rogers escreveu: > > From: Numfor Mbiziwo-Tiapo <nums@google.com> > > > > Don't perform unaligned loads in __get_next and __peek_nbyte_next as > > these are forms of undefined behavior. > > > > These problems were identified using the undefined behavior sanitizer > > (ubsan) with the tools version of the code and perf test. Part of this > > patch was previously posted here: > > https://lore.kernel.org/lkml/20190724184512.162887-4-nums@google.com/ > > Masami, if you're ok, just process it including the tools/ bit.
Hi Arnaldo,
This version updates the tools/ too, so I think this is OK. (do I need re-Ack?)
Thank you,
> > - Arnaldo > > > v4. Fixes a typo. > > > > v3. Is a rebase picking up a fix for big endian architectures. > > > > v2. removes the validate_next check and merges the 2 changes into one as > > requested by Masami Hiramatsu <mhiramat@kernel.org> > > > > Signed-off-by: Ian Rogers <irogers@google.com> > > Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com> > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > > --- > > arch/x86/lib/insn.c | 4 ++-- > > tools/arch/x86/lib/insn.c | 4 ++-- > > 2 files changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c > > index 058f19b20465..c565def611e2 100644 > > --- a/arch/x86/lib/insn.c > > +++ b/arch/x86/lib/insn.c > > @@ -37,10 +37,10 @@ > > ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) > > > > #define __get_next(t, insn) \ > > - ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) > > + ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) > > > > #define __peek_nbyte_next(t, insn, n) \ > > - ({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); }) > > + ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); }) > > > > #define get_next(t, insn) \ > > ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); }) > > diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c > > index c41f95815480..797699462cd8 100644 > > --- a/tools/arch/x86/lib/insn.c > > +++ b/tools/arch/x86/lib/insn.c > > @@ -37,10 +37,10 @@ > > ((insn)->next_byte + sizeof(t) + n <= (insn)->end_kaddr) > > > > #define __get_next(t, insn) \ > > - ({ t r = *(t*)insn->next_byte; insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) > > + ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += sizeof(t); leXX_to_cpu(t, r); }) > > > > #define __peek_nbyte_next(t, insn, n) \ > > - ({ t r = *(t*)((insn)->next_byte + n); leXX_to_cpu(t, r); }) > > + ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); leXX_to_cpu(t, r); }) > > > > #define get_next(t, insn) \ > > ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; __get_next(t, insn); }) > > -- > > 2.33.0.464.g1972c5931b-goog > > -- > > - Arnaldo
-- Masami Hiramatsu <mhiramat@kernel.org>
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