From fb6971c110387cf597b58c411658e3d15cc6c6fb Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 21 Feb 2017 13:33:41 +0000 Subject: hw/ppc/ppc405_uc.c: Avoid integer overflows MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When performing clock calculations, the ppc405_uc code has several places where it multiplies together two 32-bit variables and assigns the result to a 64-bit variable. This doesn't quite do what is intended because C will compute a 32-bit multiply result. Add casts to ensure we don't truncate the result. (Spotted by Coverity, CID 1005504, 1005505.) Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: David Gibson --- hw/ppc/ppc405_uc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'hw') diff --git a/hw/ppc/ppc405_uc.c b/hw/ppc/ppc405_uc.c index d6d3fc2c4a..d5df94aa6e 100644 --- a/hw/ppc/ppc405_uc.c +++ b/hw/ppc/ppc405_uc.c @@ -1881,7 +1881,7 @@ static void ppc405cr_clk_setup (ppc405cr_cpc_t *cpc) D1 = (((cpc->pllmr >> 20) - 1) & 0xF) + 1; /* FBDV */ D2 = 8 - ((cpc->pllmr >> 16) & 0x7); /* FWDVA */ M = D0 * D1 * D2; - VCO_out = cpc->sysclk * M; + VCO_out = (uint64_t)cpc->sysclk * M; if (VCO_out < 400000000 || VCO_out > 800000000) { /* PLL cannot lock */ cpc->pllmr &= ~0x80000000; @@ -1892,7 +1892,7 @@ static void ppc405cr_clk_setup (ppc405cr_cpc_t *cpc) /* Bypass PLL */ bypass_pll: M = D0; - PLL_out = cpc->sysclk * M; + PLL_out = (uint64_t)cpc->sysclk * M; } CPU_clk = PLL_out; if (cpc->cr1 & 0x00800000) @@ -2242,7 +2242,7 @@ static void ppc405ep_compute_clocks (ppc405ep_cpc_t *cpc) #ifdef DEBUG_CLOCKS_LL printf("FWDA %01" PRIx32 " %d\n", (cpc->pllmr[1] >> 16) & 0x7, D); #endif - VCO_out = cpc->sysclk * M * D; + VCO_out = (uint64_t)cpc->sysclk * M * D; if (VCO_out < 500000000UL || VCO_out > 1000000000UL) { /* Error - unlock the PLL */ printf("VCO out of range %" PRIu64 "\n", VCO_out); -- cgit v1.2.3