From: "Su Hang" <suhang16@mails.ucas.ac.cn>
To: "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>
Subject: [Qemu-devel] Should we check arguments for function `from_bcd` and `to_bcd`?
Date: Thu, 22 Mar 2018 15:03:03 +0800 (GMT+08:00) [thread overview]
Message-ID: <dca9a53.33fd5.1624c84a277.Coremail.suhang16@mails.ucas.ac.cn> (raw)
When I was reading 'qemu/hw/timer/m48t59.c'(Line:328) and run with
`make check-qtest-ppc`,
I found when write an invalid value 0xc to address 0x1FFF,
`from_bcd` return 12 instead of raising an exception(or error).
"""(qemu/hw/timer/m48t59.c)
case 0x1FFF:
case 0x07FF:
/* year */
tmp = from_bcd(val);
if (tmp >= 0 && tmp <= 99) {
"""
"""(qemu/include/qemu/bcd.h)
/* Convert a byte between binary and BCD. */
static inline uint8_t to_bcd(uint8_t val)
{
return ((val / 10) << 4) | (val % 10);
}
static inline uint8_t from_bcd(uint8_t val)
{
return ((val >> 4) * 10) + (val & 0x0f);
}
"""
Su Hang
next reply other threads:[~2018-03-22 7:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-22 7:03 Su Hang [this message]
2018-03-22 9:12 ` [Qemu-devel] Should we check arguments for function `from_bcd` and `to_bcd`? Paolo Bonzini
2018-03-22 10:33 ` Su Hang
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