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]> 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
