Author: ngie
Date: Fri Apr 22 18:05:34 2016
New Revision: 298485
URL: https://svnweb.freebsd.org/changeset/base/298485
Log:
Fix up pointer issues with lib/libkvm
In particular,
- avoid dereferencing NULL pointers
- test pointers against NULL, not 0
- test for errout == NULL in the top-level functions (kvm_open, kvm_openfiles,
kvm_open2, etc)
- Replace a realloc and free on failure with reallocf
Found with: devel/cocchinelle
Differential Revision: https://reviews.freebsd.org/D5954
MFC after: 1 week
Reviewed by: jhb
Sponsored by: EMC / Isilon Storage Division
Modified:
head/lib/libkvm/kvm.c
head/lib/libkvm/kvm_amd64.c
head/lib/libkvm/kvm_arm.c
head/lib/libkvm/kvm_i386.c
head/lib/libkvm/kvm_minidump_aarch64.c
head/lib/libkvm/kvm_minidump_amd64.c
head/lib/libkvm/kvm_minidump_arm.c
head/lib/libkvm/kvm_minidump_i386.c
head/lib/libkvm/kvm_minidump_mips.c
head/lib/libkvm/kvm_proc.c
Modified: head/lib/libkvm/kvm.c
==============================================================================
--- head/lib/libkvm/kvm.c Fri Apr 22 17:51:19 2016 (r298484)
+++ head/lib/libkvm/kvm.c Fri Apr 22 18:05:34 2016 (r298485)
@@ -379,12 +379,12 @@ _kvm_open(kvm_t *kd, const char *uf, con
kd->vmfd = -1;
kd->pmfd = -1;
kd->nlfd = -1;
- kd->vmst = 0;
- kd->procbase = 0;
- kd->argspc = 0;
- kd->argv = 0;
+ kd->vmst = NULL;
+ kd->procbase = NULL;
+ kd->argspc = NULL;
+ kd->argv = NULL;
- if (uf == 0)
+ if (uf == NULL)
uf = getbootfile();
else if (strlen(uf) >= MAXPATHLEN) {
_kvm_err(kd, kd->program, "exec file name too long");
@@ -394,7 +394,7 @@ _kvm_open(kvm_t *kd, const char *uf, con
_kvm_err(kd, kd->program, "bad flags arg");
goto failed;
}
- if (mf == 0)
+ if (mf == NULL)
mf = _PATH_MEM;
if ((kd->pmfd = open(mf, flag | O_CLOEXEC, 0)) < 0) {
@@ -471,7 +471,7 @@ failed:
/*
* Copy out the error if doing sane error semantics.
*/
- if (errout != 0)
+ if (errout != NULL)
strlcpy(errout, kd->errbuf, _POSIX2_LINE_MAX);
(void)kvm_close(kd);
return (0);
@@ -484,7 +484,9 @@ kvm_openfiles(const char *uf, const char
kvm_t *kd;
if ((kd = calloc(1, sizeof(*kd))) == NULL) {
- (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX);
+ if (errout != NULL)
+ (void)strlcpy(errout, strerror(errno),
+ _POSIX2_LINE_MAX);
return (0);
}
return (_kvm_open(kd, uf, mf, flag, errout));
@@ -513,7 +515,9 @@ kvm_open2(const char *uf, const char *mf
kvm_t *kd;
if ((kd = calloc(1, sizeof(*kd))) == NULL) {
- (void)strlcpy(errout, strerror(errno), _POSIX2_LINE_MAX);
+ if (errout != NULL)
+ (void)strlcpy(errout, strerror(errno),
+ _POSIX2_LINE_MAX);
return (0);
}
kd->resolve_symbol = resolver;
Modified: head/lib/libkvm/kvm_amd64.c
==============================================================================
--- head/lib/libkvm/kvm_amd64.c Fri Apr 22 17:51:19 2016 (r298484)
+++ head/lib/libkvm/kvm_amd64.c Fri Apr 22 18:05:34 2016 (r298485)
@@ -118,7 +118,7 @@ _amd64_initvtop(kvm_t *kd)
amd64_pml4e_t *PML4;
kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
- if (kd->vmst == 0) {
+ if (kd->vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
@@ -153,6 +153,10 @@ _amd64_initvtop(kvm_t *kd)
}
pa = le64toh(pa);
PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE);
+ if (PML4 == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate PML4");
+ return (-1);
+ }
if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read KPML4phys");
return (-1);
@@ -188,7 +192,7 @@ _amd64_vatop(kvm_t *kd, kvaddr_t va, off
* If we are initializing (kernel page table descriptor pointer
* not yet set) then return pa == va to avoid infinite recursion.
*/
- if (vm->PML4 == 0) {
+ if (vm->PML4 == NULL) {
s = _kvm_pa2off(kd, va, pa);
if (s == 0) {
_kvm_err(kd, kd->program,
Modified: head/lib/libkvm/kvm_arm.c
==============================================================================
--- head/lib/libkvm/kvm_arm.c Fri Apr 22 17:51:19 2016 (r298484)
+++ head/lib/libkvm/kvm_arm.c Fri Apr 22 18:05:34 2016 (r298485)
@@ -117,7 +117,7 @@ _arm_initvtop(kvm_t *kd)
}
vm = _kvm_malloc(kd, sizeof(*vm));
- if (vm == 0) {
+ if (vm == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
@@ -168,6 +168,10 @@ _arm_initvtop(kvm_t *kd)
return (-1);
}
l1pt = _kvm_malloc(kd, ARM_L1_TABLE_SIZE);
+ if (l1pt == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate l1pt");
+ return (-1);
+ }
if (kvm_read2(kd, pa, l1pt, ARM_L1_TABLE_SIZE) != ARM_L1_TABLE_SIZE) {
_kvm_err(kd, kd->program, "cannot read l1pt");
free(l1pt);
Modified: head/lib/libkvm/kvm_i386.c
==============================================================================
--- head/lib/libkvm/kvm_i386.c Fri Apr 22 17:51:19 2016 (r298484)
+++ head/lib/libkvm/kvm_i386.c Fri Apr 22 18:05:34 2016 (r298485)
@@ -162,6 +162,10 @@ _i386_initvtop(kvm_t *kd)
}
pa = le32toh(pa);
PTD = _kvm_malloc(kd, 4 * I386_PAGE_SIZE);
+ if (PTD == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate PTD");
+ return (-1);
+ }
for (i = 0; i < 4; i++) {
if (kvm_read2(kd, pa + (i * sizeof(pa64)), &pa64,
sizeof(pa64)) != sizeof(pa64)) {
@@ -195,6 +199,10 @@ _i386_initvtop(kvm_t *kd)
}
pa = le32toh(pa);
PTD = _kvm_malloc(kd, I386_PAGE_SIZE);
+ if (PTD == NULL) {
+ _kvm_err(kd, kd->program, "cannot allocate PTD");
+ return (-1);
+ }
if (kvm_read2(kd, pa, PTD, I386_PAGE_SIZE) != I386_PAGE_SIZE) {
_kvm_err(kd, kd->program, "cannot read PTD");
return (-1);
@@ -228,7 +236,7 @@ _i386_vatop(kvm_t *kd, kvaddr_t va, off_
* If we are initializing (kernel page table descriptor pointer
* not yet set) then return pa == va to avoid infinite recursion.
*/
- if (PTD == 0) {
+ if (PTD == NULL) {
s = _kvm_pa2off(kd, va, pa);
if (s == 0) {
_kvm_err(kd, kd->program,
@@ -318,7 +326,7 @@ _i386_vatop_pae(kvm_t *kd, kvaddr_t va,
* If we are initializing (kernel page table descriptor pointer
* not yet set) then return pa == va to avoid infinite recursion.
*/
- if (PTD == 0) {
+ if (PTD == NULL) {
s = _kvm_pa2off(kd, va, pa);
if (s == 0) {
_kvm_err(kd, kd->program,
Modified: head/lib/libkvm/kvm_minidump_aarch64.c
==============================================================================
--- head/lib/libkvm/kvm_minidump_aarch64.c Fri Apr 22 17:51:19 2016
(r298484)
+++ head/lib/libkvm/kvm_minidump_aarch64.c Fri Apr 22 18:05:34 2016
(r298485)
@@ -81,7 +81,7 @@ _aarch64_minidump_initvtop(kvm_t *kd)
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
- if (vmst == 0) {
+ if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
Modified: head/lib/libkvm/kvm_minidump_amd64.c
==============================================================================
--- head/lib/libkvm/kvm_minidump_amd64.c Fri Apr 22 17:51:19 2016
(r298484)
+++ head/lib/libkvm/kvm_minidump_amd64.c Fri Apr 22 18:05:34 2016
(r298485)
@@ -81,7 +81,7 @@ _amd64_minidump_initvtop(kvm_t *kd)
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
- if (vmst == 0) {
+ if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
Modified: head/lib/libkvm/kvm_minidump_arm.c
==============================================================================
--- head/lib/libkvm/kvm_minidump_arm.c Fri Apr 22 17:51:19 2016
(r298484)
+++ head/lib/libkvm/kvm_minidump_arm.c Fri Apr 22 18:05:34 2016
(r298485)
@@ -84,7 +84,7 @@ _arm_minidump_initvtop(kvm_t *kd)
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
- if (vmst == 0) {
+ if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
Modified: head/lib/libkvm/kvm_minidump_i386.c
==============================================================================
--- head/lib/libkvm/kvm_minidump_i386.c Fri Apr 22 17:51:19 2016
(r298484)
+++ head/lib/libkvm/kvm_minidump_i386.c Fri Apr 22 18:05:34 2016
(r298485)
@@ -81,7 +81,7 @@ _i386_minidump_initvtop(kvm_t *kd)
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
- if (vmst == 0) {
+ if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
Modified: head/lib/libkvm/kvm_minidump_mips.c
==============================================================================
--- head/lib/libkvm/kvm_minidump_mips.c Fri Apr 22 17:51:19 2016
(r298484)
+++ head/lib/libkvm/kvm_minidump_mips.c Fri Apr 22 18:05:34 2016
(r298485)
@@ -89,7 +89,7 @@ _mips_minidump_initvtop(kvm_t *kd)
off_t off;
vmst = _kvm_malloc(kd, sizeof(*vmst));
- if (vmst == 0) {
+ if (vmst == NULL) {
_kvm_err(kd, kd->program, "cannot allocate vm");
return (-1);
}
Modified: head/lib/libkvm/kvm_proc.c
==============================================================================
--- head/lib/libkvm/kvm_proc.c Fri Apr 22 17:51:19 2016 (r298484)
+++ head/lib/libkvm/kvm_proc.c Fri Apr 22 18:05:34 2016 (r298485)
@@ -544,7 +544,7 @@ kvm_getprocs(kvm_t *kd, int op, int arg,
size += size / 10;
kd->procbase = (struct kinfo_proc *)
_kvm_realloc(kd, kd->procbase, size);
- if (kd->procbase == 0)
+ if (kd->procbase == NULL)
return (0);
osize = size;
st = sysctl(mib, temp_op == KERN_PROC_ALL ||
@@ -614,7 +614,7 @@ liveout:
}
size = nprocs * sizeof(struct kinfo_proc);
kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
- if (kd->procbase == 0)
+ if (kd->procbase == NULL)
return (0);
nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
@@ -637,21 +637,19 @@ liveout:
void
_kvm_freeprocs(kvm_t *kd)
{
- if (kd->procbase) {
- free(kd->procbase);
- kd->procbase = 0;
- }
+
+ free(kd->procbase);
+ kd->procbase = NULL;
}
void *
_kvm_realloc(kvm_t *kd, void *p, size_t n)
{
- void *np = (void *)realloc(p, n);
+ void *np;
- if (np == 0) {
- free(p);
+ np = reallocf(p, n);
+ if (np == NULL)
_kvm_err(kd, kd->program, "out of memory");
- }
return (np);
}
@@ -672,7 +670,7 @@ kvm_argv(kvm_t *kd, const struct kinfo_p
if (!ISALIVE(kd)) {
_kvm_err(kd, kd->program,
"cannot read user space from dead kernel");
- return (0);
+ return (NULL);
}
if (nchr == 0 || nchr > ARG_MAX)
@@ -681,7 +679,7 @@ kvm_argv(kvm_t *kd, const struct kinfo_p
buf = malloc(nchr);
if (buf == NULL) {
_kvm_err(kd, kd->program, "cannot allocate memory");
- return (0);
+ return (NULL);
}
buflen = nchr;
argc = 32;
@@ -706,12 +704,11 @@ kvm_argv(kvm_t *kd, const struct kinfo_p
* to the requested len.
*/
if (errno != ENOMEM || bufsz != (size_t)buflen)
- return (0);
+ return (NULL);
buf[bufsz - 1] = '\0';
errno = 0;
- } else if (bufsz == 0) {
- return (0);
- }
+ } else if (bufsz == 0)
+ return (NULL);
i = 0;
p = buf;
do {
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