svn commit: r361011 - in head/sys: ddb dev/amdtemp dev/nvdimm dev/ow net sys vm
Kyle Evans
kevans at FreeBSD.org
Wed May 13 18:07:39 UTC 2020
Author: kevans
Date: Wed May 13 18:07:37 2020
New Revision: 361011
URL: https://svnweb.freebsd.org/changeset/base/361011
Log:
kernel: provide panicky version of __unreachable
__builtin_unreachable doesn't raise any compile-time warnings/errors on its
own, so problems with its usage can't be easily detected. While it would be
nice for this situation to change and compilers to at least add a warning
for trivial cases where local state means the instruction can't be reached,
this isn't the case at the moment and likely will not happen.
This commit adds an __assert_unreachable, whose intent is incredibly clear:
it asserts that this instruction is unreachable. On INVARIANTS builds, it's
a panic(), and on non-INVARIANTS it expands to __unreachable().
Existing users of __unreachable() are converted to __assert_unreachable,
to improve debuggability if this assumption is violated.
Reviewed by: mjg
Differential Revision: https://reviews.freebsd.org/D23793
Modified:
head/sys/ddb/db_expr.c
head/sys/dev/amdtemp/amdtemp.c
head/sys/dev/nvdimm/nvdimm.c
head/sys/dev/ow/ow.c
head/sys/net/mppcc.c
head/sys/sys/systm.h
head/sys/vm/vm_radix.c
Modified: head/sys/ddb/db_expr.c
==============================================================================
--- head/sys/ddb/db_expr.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/ddb/db_expr.c Wed May 13 18:07:37 2020 (r361011)
@@ -34,6 +34,7 @@
__FBSDID("$FreeBSD$");
#include <sys/param.h>
+#include <sys/systm.h>
#include <ddb/ddb.h>
#include <ddb/db_lex.h>
@@ -229,7 +230,7 @@ db_add_expr(db_expr_t *valuep)
lhs |= rhs;
break;
default:
- __unreachable();
+ __assert_unreachable();
}
t = db_read_token();
}
@@ -313,7 +314,7 @@ db_logical_relation_expr(
lhs = (lhs <= rhs);
break;
default:
- __unreachable();
+ __assert_unreachable();
}
t = db_read_token();
}
Modified: head/sys/dev/amdtemp/amdtemp.c
==============================================================================
--- head/sys/dev/amdtemp/amdtemp.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/dev/amdtemp/amdtemp.c Wed May 13 18:07:37 2020 (r361011)
@@ -666,7 +666,7 @@ amdtemp_gettemp0f(device_t dev, amdsensor_t sensor)
temp |= AMDTEMP_TTSR_SELCORE;
break;
default:
- __unreachable();
+ __assert_unreachable();
}
pci_write_config(dev, AMDTEMP_THERMTP_STAT, temp, 1);
@@ -766,7 +766,7 @@ amdtemp_gettemp17h(device_t dev, amdsensor_t sensor)
("sensor %d: not valid", (int)sensor));
return (amdtemp_decode_fam10h_to_17h(sc->sc_offset, val, true));
default:
- __unreachable();
+ __assert_unreachable();
}
}
Modified: head/sys/dev/nvdimm/nvdimm.c
==============================================================================
--- head/sys/dev/nvdimm/nvdimm.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/dev/nvdimm/nvdimm.c Wed May 13 18:07:37 2020 (r361011)
@@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
+#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/bitstring.h>
#include <sys/bus.h>
@@ -236,7 +237,7 @@ read_label(struct nvdimm_dev *nv, int num)
return (0);
}
}
- __unreachable();
+ __assert_unreachable();
}
static int
Modified: head/sys/dev/ow/ow.c
==============================================================================
--- head/sys/dev/ow/ow.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/dev/ow/ow.c Wed May 13 18:07:37 2020 (r361011)
@@ -507,7 +507,7 @@ again:
return (EIO);
goto again;
default: /* NOTREACHED */
- __unreachable();
+ __assert_unreachable();
}
if (dir) {
OWLL_WRITE_ONE(lldev, &timing_regular);
Modified: head/sys/net/mppcc.c
==============================================================================
--- head/sys/net/mppcc.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/net/mppcc.c Wed May 13 18:07:37 2020 (r361011)
@@ -232,7 +232,7 @@ int MPPC_Compress(u_char **src, u_char **dst, u_long *
} else if (off < 8192) { /* 16-bit offset; 320 <= offset < 8192 */
putbits16(*dst, 0xc000|(off-320), 16, &olen, &l);
} else { /* NOTREACHED */
- __unreachable();
+ __assert_unreachable();
rtn &= ~MPPC_OK;
return (rtn);
}
Modified: head/sys/sys/systm.h
==============================================================================
--- head/sys/sys/systm.h Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/sys/systm.h Wed May 13 18:07:37 2020 (r361011)
@@ -117,6 +117,9 @@ void kassert_panic(const char *fmt, ...) __printflike
VNASSERT(exp, vp, ("condition %s not met at %s:%d (%s)", \
_exp, __FILE__, __LINE__, __func__)); \
} while (0)
+#define __assert_unreachable() \
+ panic("executing segment marked as unreachable at %s:%d (%s)\n", \
+ __FILE__, __LINE__, __func__)
#else
#define KASSERT(exp,msg) do { \
} while (0)
@@ -125,6 +128,7 @@ void kassert_panic(const char *fmt, ...) __printflike
} while (0)
#define VNPASS(exp, vp) do { \
} while (0)
+#define __assert_unreachable() __unreachable()
#endif
#ifndef CTASSERT /* Allow lint to override */
Modified: head/sys/vm/vm_radix.c
==============================================================================
--- head/sys/vm/vm_radix.c Wed May 13 17:20:51 2020 (r361010)
+++ head/sys/vm/vm_radix.c Wed May 13 18:07:37 2020 (r361011)
@@ -209,7 +209,7 @@ vm_radix_node_load(smrnode_t *p, enum vm_radix_access
case SMR:
return (smr_entered_load(p, vm_radix_smr));
}
- __unreachable();
+ __assert_unreachable();
}
static __inline void
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