Commit cf5f7937 authored by Peter Maydell's avatar Peter Maydell
Browse files

nvic: Fix miscalculation of offsets into ITNS array 



This calculation of the first exception vector in
the ITNS<n> register being accessed:
        int startvec = 32 * (offset - 0x380) + NVIC_FIRST_IRQ;

is incorrect, because offset is in bytes, so we only want
to multiply by 8.

Spotted by Coverity (CID 1381484, CID 1381488), though it is
not correct that it actually overflows the buffer, because
we have a 'startvec + i < s->num_irq' guard.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Message-id: 1507650856-11718-1-git-send-email-peter.maydell@linaro.org
parent a94bb9cd

hw/intc/armv7m_nvic.c

+2 −2
Original line number Diff line number Diff line
@@ -698,7 +698,7 @@ static uint32_t nvic_readl(NVICState *s, uint32_t offset, MemTxAttrs attrs) 
        return ((s->num_irq - NVIC_FIRST_IRQ) / 32) - 1;

    case 0x380 ... 0x3bf: /* NVIC_ITNS<n> */

    {

        int startvec = 32 * (offset - 0x380) + NVIC_FIRST_IRQ;

        int startvec = 8 * (offset - 0x380) + NVIC_FIRST_IRQ;

        int i;



        if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {
@@ -1102,7 +1102,7 @@ static void nvic_writel(NVICState *s, uint32_t offset, uint32_t value, 
    switch (offset) {

    case 0x380 ... 0x3bf: /* NVIC_ITNS<n> */

    {

        int startvec = 32 * (offset - 0x380) + NVIC_FIRST_IRQ;

        int startvec = 8 * (offset - 0x380) + NVIC_FIRST_IRQ;

        int i;



        if (!arm_feature(&cpu->env, ARM_FEATURE_V8)) {