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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::635; envelope-from=philmd@linaro.org; helo=mail-ej1-x635.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 9/11/23 16:54, Cédric Le Goater wrote: > On 11/9/23 16:02, Peter Maydell wrote: >> On Thu, 9 Nov 2023 at 08:06, Cédric Le Goater wrote: >>> >>> Coverity warns that "i2c_bus_busy(i2c->busses[i]) << i" might overflow >>> because the expression is evaluated using 32-bit arithmetic and then >>> used in a context expecting a uint64_t. >>> >>> Fixes: Coverity CID 1523918 >>> Cc: Glenn Miles >>> Signed-off-by: Cédric Le Goater >>> --- >>>   hw/ppc/pnv_i2c.c | 2 +- >>>   1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/hw/ppc/pnv_i2c.c b/hw/ppc/pnv_i2c.c >>> index f75e59e70977..ab73c59f7704 100644 >>> --- a/hw/ppc/pnv_i2c.c >>> +++ b/hw/ppc/pnv_i2c.c >>> @@ -437,7 +437,7 @@ static uint64_t pnv_i2c_xscom_read(void *opaque, >>> hwaddr addr, >>>       case I2C_PORT_BUSY_REG: /* compute busy bit for each port  */ >>>           val = 0; >>>           for (i = 0; i < i2c->num_busses; i++) { >>> -            val |= i2c_bus_busy(i2c->busses[i]) << i; >>> +            val |= (uint64_t) i2c_bus_busy(i2c->busses[i]) << i; >>>           } >>>           break; >> >> Should the device's realize function also impose a max >> limit on the num-busses property? There doesn't seem to be >> anything preventing a caller from setting it to a big >> number like 128, which would then be UB here. > > yes. I will add an assert(i2c->num_busses < 64). The current max > is 16 for POWER10. > >> Style nit: casts shouldn't have a space after them before >> the thing they're casting. > > yep. > > I prefer the cast method than the deposit call. Philippe, I hope you > don't mind ? Matter of taste, I don't mind ¯\_(ツ)_/¯