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authorKees Cook <keescook@chromium.org>2020-02-20 09:23:08 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-23 22:28:12 +0300
commit78c244226613c938729dc5528738df6157a77dd1 (patch)
tree867a379a985cbc9b0e006e4eeda2e88d7341e65c /drivers/char
parent78856f25510369bfdc385b867303cab6a071d13d (diff)
downloadlinux-78c244226613c938729dc5528738df6157a77dd1.tar.xz
pcmcia: Distribute switch variables for initialization
Variables declared in a switch statement before any case statements cannot be automatically initialized with compiler instrumentation (as they are not part of any execution flow). With GCC's proposed automatic stack variable initialization feature, this triggers a warning (and they don't get initialized). Clang's automatic stack variable initialization (via CONFIG_INIT_STACK_ALL=y) doesn't throw a warning, but it also doesn't initialize such variables[1]. Note that these warnings (or silent skipping) happen before the dead-store elimination optimization phase, so even when the automatic initializations are later elided in favor of direct initializations, the warnings remain. To avoid these problems, move such variables into the "case" where they're used or lift them up into the main function body. drivers/char/pcmcia/cm4000_cs.c: In function ‘monitor_card’: drivers/char/pcmcia/cm4000_cs.c:734:17: warning: statement will never be executed [-Wswitch-unreachable] 734 | unsigned char flags0; | ^~~~~~ [1] https://bugs.llvm.org/show_bug.cgi?id=44916 Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200220062308.69032-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/pcmcia/cm4000_cs.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index 15bf585af5d3..4edb4174a1e2 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -731,8 +731,9 @@ static void monitor_card(struct timer_list *t)
}
switch (dev->mstate) {
+ case M_CARDOFF: {
unsigned char flags0;
- case M_CARDOFF:
+
DEBUGP(4, dev, "M_CARDOFF\n");
flags0 = inb(REG_FLAGS0(iobase));
if (flags0 & 0x02) {
@@ -755,6 +756,7 @@ static void monitor_card(struct timer_list *t)
dev->mdelay = T_50MSEC;
}
break;
+ }
case M_FETCH_ATR:
DEBUGP(4, dev, "M_FETCH_ATR\n");
xoutb(0x80, REG_FLAGS0(iobase));