On Thu, 15 Oct 2020 09:12:16 -0700 Ian Rogers <[email protected]> wrote:
> From: Numfor Mbiziwo-Tiapo <[email protected]> > > 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/[email protected]/ > > v2. removes the validate_next check and merges the 2 changes into one as > requested by Masami Hiramatsu <[email protected]> Looks good to me. This may be OK on x86, but now this code will be run on other arches for cross compilation. Acked-by: Masami Hiramatsu <[email protected]> Thank you, > > Signed-off-by: Ian Rogers <[email protected]> > Signed-off-by: Numfor Mbiziwo-Tiapo <[email protected]> > --- > 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 404279563891..be88ab250146 100644 > --- a/arch/x86/lib/insn.c > +++ b/arch/x86/lib/insn.c > @@ -20,10 +20,10 @@ > ((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); r; }) > + ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += > sizeof(t); r; }) > > #define __peek_nbyte_next(t, insn, n) \ > - ({ t r = *(t*)((insn)->next_byte + n); r; }) > + ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(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 0151dfc6da61..92358c71a59e 100644 > --- a/tools/arch/x86/lib/insn.c > +++ b/tools/arch/x86/lib/insn.c > @@ -20,10 +20,10 @@ > ((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); r; }) > + ({ t r; memcpy(&r, insn->next_byte, sizeof(t)); insn->next_byte += > sizeof(t); r; }) > > #define __peek_nbyte_next(t, insn, n) \ > - ({ t r = *(t*)((insn)->next_byte + n); r; }) > + ({ t r; memcpy(&r, (insn)->next_byte + n, sizeof(t)); r; }) > > #define get_next(t, insn) \ > ({ if (unlikely(!validate_next(t, insn, 0))) goto err_out; > __get_next(t, insn); }) > -- > 2.28.0.1011.ga647a8990f-goog > -- Masami Hiramatsu <[email protected]>
