x86/kernel: Mark expected switch-case fall-throughs

In preparation to enable -Wimplicit-fallthrough by default, mark
switch-case statements where fall-through is intentional, explicitly in
order to fix a couple of -Wimplicit-fallthrough warnings.

Warning level 3 was used: -Wimplicit-fallthrough=3.

 [ bp: Massasge and trim commit message. ]

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: David Wang <davidwang@zhaoxin.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pu Wen <puwen@hygon.cn>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190125183903.GA4712@embeddedor

diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 2953bbf..264e322 100644 (file)
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -812,6 +812,7 @@ static int irq_polarity(int idx)
                return IOAPIC_POL_HIGH;
        case MP_IRQPOL_RESERVED:
                pr_warn("IOAPIC: Invalid polarity: 2, defaulting to low\n");
+               /* fall through */
        case MP_IRQPOL_ACTIVE_LOW:
        default: /* Pointless default required due to do gcc stupidity */
                return IOAPIC_POL_LOW;
@@ -859,6 +860,7 @@ static int irq_trigger(int idx)
                return IOAPIC_EDGE;
        case MP_IRQTRIG_RESERVED:
                pr_warn("IOAPIC: Invalid trigger mode 2 defaulting to level\n");
+               /* fall through */
        case MP_IRQTRIG_LEVEL:
        default: /* Pointless default required due to do gcc stupidity */
                return IOAPIC_LEVEL;

diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index c4d1023..395d46f 100644 (file)
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -248,6 +248,7 @@ amd_cpuid4(int leaf, union _cpuid4_leaf_eax *eax,
        switch (leaf) {
        case 1:
                l1 = &l1i;
+               /* fall through */
        case 0:
                if (!l1->val)
                        return;

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 34a5c17..7d6f91f 100644 (file)
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -279,6 +279,7 @@ static int arch_build_bp_info(struct perf_event *bp,
                        hw->len = X86_BREAKPOINT_LEN_X;
                        return 0;
                }
+               /* fall through */
        default:
                return -EINVAL;
        }

diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 5db0842..4ff6b4c 100644 (file)
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -467,6 +467,7 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
                ptr = &remcomInBuffer[1];
                if (kgdb_hex2long(&ptr, &addr))
                        linux_regs->ip = addr;
+               /* fall through */
        case 'D':
        case 'k':
                /* clear the trace bit */

diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 843feb9..ccf0341 100644 (file)
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -745,6 +745,7 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn)
                 * OPCODE1() of the "short" jmp which checks the same condition.
                 */
                opc1 = OPCODE2(insn) - 0x10;
+               /* fall through */
        default:
                if (!is_cond_jmp_opcode(opc1))
                        return -ENOSYS;