Commit graph

5 commits

Author SHA1 Message Date
Peter Maydell b9e3f1579a hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
In commit 81b3ddaf87 we fixed a use of uninitialized data
in read_tcnt(). However this change wasn't enough to placate
Coverity, which is not smart enough to see that if we read a
2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
be a flow of execution through the switch default. Add explicit
default cases which assert that they can't be reached, which
should help silence Coverity.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210319162458.13760-1-peter.maydell@linaro.org
2021-03-30 14:05:34 +01:00
Peter Maydell 81b3ddaf87 hw/timer/renesas_tmr: Fix use of uninitialized data in read_tcnt()
The read_tcnt() function calculates the TCNT register values for the
two channels of the timer module; it sets these up in the local
tcnt[] array, and eventually returns either one or both of them,
depending on whether the access is 8 or 16 bits.  However, not all of
the code paths through this function set both elements of this array:
if the guest has programmed the TCCR.CSS register fields to values
which are either documented as not to be used or which QEMU does not
implement, then the function will return uninitialized data.  (This
was spotted by Coverity.)

Add the missing CSS cases to this code, so that we return a
consistent value instead of uninitialized data, and so the code
structure indicates what's happening.

Fixes: CID 1429976
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210219223241.16344-3-peter.maydell@linaro.org
2021-03-10 13:54:51 +00:00
Peter Maydell 02f8fe11f7 hw/timer/renesas_tmr: Prefix constants for CSS values with CSS_
The #defines INTERNAL and CASCADING represent different possible
values for the TCCR.CSS register field; prefix them with CSS_ to make
this more obvious, before we add more defines to represent the
other possible values of the field in the next commit.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210219223241.16344-2-peter.maydell@linaro.org
2021-03-10 13:54:51 +00:00
Chen Qun 30982862b2 hw/timer/renesas_tmr: silence the compiler warnings
When using -Wimplicit-fallthrough in our CFLAGS, the compiler showed warning:
../hw/timer/renesas_tmr.c: In function ‘tmr_read’:
../hw/timer/renesas_tmr.c:221:19: warning: this statement may fall through [-Wimplicit-fallthrough=]
  221 |         } else if (ch == 0) {i
      |                   ^
../hw/timer/renesas_tmr.c:224:5: note: here
  224 |     case A_TCORB:
      |     ^~~~

Add the corresponding "fall through" comment to fix it.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20201211152426.350966-5-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2020-12-18 09:14:23 +01:00
Yoshinori Sato 7adca78eda hw/timer: RX62N 8-Bit timer (TMR)
renesas_tmr: 8bit timer modules.
This part use many renesas's CPU.
Hardware manual.
https://www.renesas.com/us/en/doc/products/mpumcu/doc/rx_family/r01uh0033ej0140_rx62n.pdf

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200224141923.82118-16-ysato@users.sourceforge.jp>
[PMD: Split from CMT, filled VMStateField for migration]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2020-06-22 18:37:12 +02:00