Commit 88c50834 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'Wimplicit-fallthrough-5.3-rc2' of...

Merge tag 'Wimplicit-fallthrough-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux

Pull Wimplicit-fallthrough enablement from Gustavo A. R. Silva:
 "This marks switch cases where we are expecting to fall through, and
  globally enables the -Wimplicit-fallthrough option in the main
  Makefile.

  Finally, some missing-break fixes that have been tagged for -stable:

   - drm/amdkfd: Fix missing break in switch statement

   - drm/amdgpu/gfx10: Fix missing break in switch statement

  With these changes, we completely get rid of all the fall-through
  warnings in the kernel"

* tag 'Wimplicit-fallthrough-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
  Makefile: Globally enable fall-through warning
  drm/i915: Mark expected switch fall-throughs
  drm/amd/display: Mark expected switch fall-throughs
  drm/amdkfd/kfd_mqd_manager_v10: Avoid fall-through warning
  drm/amdgpu/gfx10: Fix missing break in switch statement
  drm/amdkfd: Fix missing break in switch statement
  perf/x86/intel: Mark expected switch fall-throughs
  mtd: onenand_base: Mark expected switch fall-through
  afs: fsclient: Mark expected switch fall-throughs
  afs: yfsclient: Mark expected switch fall-throughs
  can: mark expected switch fall-throughs
  firewire: mark expected switch fall-throughs
parents 43e317c1 a035d552
......@@ -119,3 +119,17 @@ array may exceed the remaining memory in the stack segment. This could
lead to a crash, possible overwriting sensitive contents at the end of the
stack (when built without `CONFIG_THREAD_INFO_IN_TASK=y`), or overwriting
memory adjacent to the stack (when built without `CONFIG_VMAP_STACK=y`)
Implicit switch case fall-through
---------------------------------
The C language allows switch cases to "fall through" when
a "break" statement is missing at the end of a case. This,
however, introduces ambiguity in the code, as it's not always
clear if the missing break is intentional or a bug. As there
have been a long list of flaws `due to missing "break" statements
<https://cwe.mitre.org/data/definitions/484.html>`_, we no longer allow
"implicit fall-through". In order to identify an intentional fall-through
case, we have adopted the marking used by static analyzers: a comment
saying `/* Fall through */`. Once the C++17 `__attribute__((fallthrough))`
is more widely handled by C compilers, static analyzers, and IDEs, we can
switch to using that instead.
......@@ -843,6 +843,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
# warn about C99 declaration after statement
KBUILD_CFLAGS += -Wdeclaration-after-statement
# Warn about unmarked fall-throughs in switch statement.
KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=3,)
# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
KBUILD_CFLAGS += -Wvla
......
......@@ -4955,6 +4955,7 @@ __init int intel_pmu_init(void)
case INTEL_FAM6_SKYLAKE_X:
pmem = true;
/* fall through */
case INTEL_FAM6_SKYLAKE_MOBILE:
case INTEL_FAM6_SKYLAKE_DESKTOP:
case INTEL_FAM6_KABYLAKE_MOBILE:
......@@ -5004,6 +5005,7 @@ __init int intel_pmu_init(void)
case INTEL_FAM6_ICELAKE_X:
case INTEL_FAM6_ICELAKE_XEON_D:
pmem = true;
/* fall through */
case INTEL_FAM6_ICELAKE_MOBILE:
case INTEL_FAM6_ICELAKE_DESKTOP:
x86_pmu.late_ack = true;
......
......@@ -957,7 +957,7 @@ static void set_broadcast_channel(struct fw_device *device, int generation)
device->bc_implemented = BC_IMPLEMENTED;
break;
}
/* else fall through to case address error */
/* else, fall through - to case address error */
case RCODE_ADDRESS_ERROR:
device->bc_implemented = BC_UNIMPLEMENTED;
}
......
......@@ -284,7 +284,7 @@ static int manage_channel(struct fw_card *card, int irm_id, int generation,
if ((data[0] & bit) == (data[1] & bit))
continue;
/* 1394-1995 IRM, fall through to retry. */
/* fall through - It's a 1394-1995 IRM, retry. */
default:
if (retry) {
retry--;
......
......@@ -54,6 +54,7 @@ static u32 *count_ports(u32 *sid, int *total_port_count, int *child_port_count)
switch (port_type) {
case SELFID_PORT_CHILD:
(*child_port_count)++;
/* fall through */
case SELFID_PORT_PARENT:
case SELFID_PORT_NCONN:
(*total_port_count)++;
......
......@@ -4620,6 +4620,7 @@ gfx_v10_0_set_gfx_eop_interrupt_state(struct amdgpu_device *adev,
cp_int_cntl = REG_SET_FIELD(cp_int_cntl, CP_INT_CNTL_RING0,
TIME_STAMP_INT_ENABLE, 0);
WREG32(cp_int_cntl_reg, cp_int_cntl);
break;
case AMDGPU_IRQ_STATE_ENABLE:
cp_int_cntl = RREG32(cp_int_cntl_reg);
cp_int_cntl = REG_SET_FIELD(cp_int_cntl, CP_INT_CNTL_RING0,
......
......@@ -668,6 +668,7 @@ static int kfd_fill_gpu_cache_info(struct kfd_dev *kdev,
case CHIP_RAVEN:
pcache_info = raven_cache_info;
num_of_cache_types = ARRAY_SIZE(raven_cache_info);
break;
case CHIP_NAVI10:
pcache_info = navi10_cache_info;
num_of_cache_types = ARRAY_SIZE(navi10_cache_info);
......
......@@ -429,7 +429,6 @@ struct mqd_manager *mqd_manager_init_v10(enum KFD_MQD_TYPE type,
switch (type) {
case KFD_MQD_TYPE_CP:
pr_debug("%s@%i\n", __func__, __LINE__);
case KFD_MQD_TYPE_COMPUTE:
pr_debug("%s@%i\n", __func__, __LINE__);
mqd->allocate_mqd = allocate_mqd;
......
......@@ -102,14 +102,19 @@ void dccg2_init(struct dccg *dccg)
switch (dccg_dcn->base.ctx->dc->res_pool->pipe_count) {
case 6:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[5], 1);
/* Fall through */
case 5:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[4], 1);
/* Fall through */
case 4:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[3], 1);
/* Fall through */
case 3:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[2], 1);
/* Fall through */
case 2:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[1], 1);
/* Fall through */
case 1:
REG_UPDATE(DPPCLK_DTO_CTRL, DPPCLK_DTO_DB_EN[0], 1);
break;
......
......@@ -16,7 +16,6 @@ subdir-ccflags-y := -Wall -Wextra
subdir-ccflags-y += $(call cc-disable-warning, unused-parameter)
subdir-ccflags-y += $(call cc-disable-warning, type-limits)
subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers)
subdir-ccflags-y += $(call cc-disable-warning, implicit-fallthrough)
subdir-ccflags-y += $(call cc-disable-warning, unused-but-set-variable)
# clang warnings
subdir-ccflags-y += $(call cc-disable-warning, sign-compare)
......
......@@ -12042,7 +12042,7 @@ static bool check_digital_port_conflicts(struct intel_atomic_state *state)
case INTEL_OUTPUT_DDI:
if (WARN_ON(!HAS_DDI(to_i915(dev))))
break;
/* else: fall through */
/* else, fall through */
case INTEL_OUTPUT_DP:
case INTEL_OUTPUT_HDMI:
case INTEL_OUTPUT_EDP:
......
......@@ -231,6 +231,7 @@ static int intel_dp_get_fia_supported_lane_count(struct intel_dp *intel_dp)
switch (lane_info) {
default:
MISSING_CASE(lane_info);
/* fall through */
case 1:
case 2:
case 4:
......
......@@ -341,7 +341,7 @@ err:
*/
if (!i915_terminally_wedged(i915))
return VM_FAULT_SIGBUS;
/* else: fall through */
/* else, fall through */
case -EAGAIN:
/*
* EAGAIN means the gpu is hung and we'll wait for the error
......
......@@ -268,7 +268,7 @@ static void *i915_gem_object_map(const struct drm_i915_gem_object *obj,
switch (type) {
default:
MISSING_CASE(type);
/* fallthrough to use PAGE_KERNEL anyway */
/* fallthrough - to use PAGE_KERNEL anyway */
case I915_MAP_WB:
pgprot = PAGE_KERNEL;
break;
......
......@@ -1194,6 +1194,7 @@ static void error_record_engine_registers(struct i915_gpu_state *error,
switch (engine->id) {
default:
MISSING_CASE(engine->id);
/* fall through */
case RCS0:
mmio = RENDER_HWS_PGA_GEN7;
break;
......
......@@ -3259,6 +3259,7 @@ static void onenand_check_features(struct mtd_info *mtd)
switch (density) {
case ONENAND_DEVICE_DENSITY_8Gb:
this->options |= ONENAND_HAS_NOP_1;
/* fall through */
case ONENAND_DEVICE_DENSITY_4Gb:
if (ONENAND_IS_DDP(this))
this->options |= ONENAND_HAS_2PLANE;
......
......@@ -898,7 +898,8 @@ static void at91_irq_err_state(struct net_device *dev,
CAN_ERR_CRTL_TX_WARNING :
CAN_ERR_CRTL_RX_WARNING;
}
case CAN_STATE_ERROR_WARNING: /* fallthrough */
/* fall through */
case CAN_STATE_ERROR_WARNING:
/*
* from: ERROR_ACTIVE, ERROR_WARNING
* to : ERROR_PASSIVE, BUS_OFF
......@@ -947,7 +948,8 @@ static void at91_irq_err_state(struct net_device *dev,
netdev_dbg(dev, "Error Active\n");
cf->can_id |= CAN_ERR_PROT;
cf->data[2] = CAN_ERR_PROT_ACTIVE;
case CAN_STATE_ERROR_WARNING: /* fallthrough */
/* fall through */
case CAN_STATE_ERROR_WARNING:
reg_idr = AT91_IRQ_ERRA | AT91_IRQ_WARN | AT91_IRQ_BOFF;
reg_ier = AT91_IRQ_ERRP;
break;
......
......@@ -660,7 +660,7 @@ static int pciefd_can_probe(struct pciefd_board *pciefd)
pciefd_can_writereg(priv, CANFD_CLK_SEL_80MHZ,
PCIEFD_REG_CAN_CLK_SEL);
/* fallthough */
/* fall through */
case CANFD_CLK_SEL_80MHZ:
priv->ucan.can.clock.freq = 80 * 1000 * 1000;
break;
......
......@@ -860,7 +860,8 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
if (new_state >= CAN_STATE_ERROR_WARNING &&
new_state <= CAN_STATE_BUS_OFF)
priv->can.can_stats.error_warning++;
case CAN_STATE_ERROR_WARNING: /* fallthrough */
/* fall through */
case CAN_STATE_ERROR_WARNING:
if (new_state >= CAN_STATE_ERROR_PASSIVE &&
new_state <= CAN_STATE_BUS_OFF)
priv->can.can_stats.error_passive++;
......
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