diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2017-02-21 13:33:41 +0000 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2017-02-22 14:28:53 +1100 |
| commit | fb6971c110387cf597b58c411658e3d15cc6c6fb (patch) | |
| tree | 9c732699ce1a6457f1c30cb0aa4f2df8845e32b3 | |
| parent | df58713396f8b2deb923e39c00b10744c5c63909 (diff) | |
hw/ppc/ppc405_uc.c: Avoid integer overflows
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 <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
| -rw-r--r-- | hw/ppc/ppc405_uc.c | 6 |
1 files changed, 3 insertions, 3 deletions
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); |