Attachment 217019 Details for Bug 248250 – preliminary patch

[patch] preliminary patch

patch_env (text/plain), 7.88 KB, created by Jason A. Harmening on 2020-08-05 06:38:53 UTC

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Creator: Jason A. Harmening

Created: 2020-08-05 06:38:53 UTC

Size: 7.88 KB

patch

obsolete

>Index: sys/kern/kern_environment.c
>===================================================================
>--- sys/kern/kern_environment.c	(revision 363749)
>+++ sys/kern/kern_environment.c	(working copy)
>@@ -44,7 +44,7 @@
> #include <sys/queue.h>
> #include <sys/lock.h>
> #include <sys/malloc.h>
>-#include <sys/mutex.h>
>+#include <sys/rmlock.h>
> #include <sys/priv.h>
> #include <sys/kernel.h>
> #include <sys/systm.h>
>@@ -78,7 +78,7 @@
> 
> /* dynamic environment variables */
> char		**kenvp;
>-struct mtx	kenv_lock;
>+struct rmlock	kenv_lock;
> 
> /*
>  * No need to protect this with a mutex since SYSINITS are single threaded.
>@@ -100,6 +100,7 @@
> 		int len;
> 	} */ *uap;
> {
>+	struct rm_priotracker tracker;
> 	char *name, *value, *buffer = NULL;
> 	size_t len, done, needed, buflen;
> 	int error, i;
>@@ -120,7 +121,7 @@
> 			    kenv_mvallen + 2);
> 		if (uap->len > 0 && uap->value != NULL)
> 			buffer = malloc(buflen, M_TEMP, M_WAITOK|M_ZERO);
>-		mtx_lock(&kenv_lock);
>+		rm_rlock(&kenv_lock, &tracker);
> 		for (i = 0; kenvp[i] != NULL; i++) {
> 			len = strlen(kenvp[i]) + 1;
> 			needed += len;
>@@ -134,7 +135,7 @@
> 				done += len;
> 			}
> 		}
>-		mtx_unlock(&kenv_lock);
>+		rm_runlock(&kenv_lock, &tracker);
> 		if (buffer != NULL) {
> 			error = copyout(buffer, uap->value, done);
> 			free(buffer, M_TEMP);
>@@ -396,7 +397,7 @@
> 	init_dynamic_kenv_from(kern_envp, &dynamic_envpos);
> 	kenvp[dynamic_envpos] = NULL;
> 
>-	mtx_init(&kenv_lock, "kernel environment", NULL, MTX_DEF);
>+	rm_init(&kenv_lock, "kernel environment");
> 	dynamic_kenv = true;
> }
> SYSINIT(kenv, SI_SUB_KMEM + 1, SI_ORDER_FIRST, init_dynamic_kenv, NULL);
>@@ -436,7 +437,7 @@
> _getenv_dynamic(const char *name, int *idx)
> {
> 
>-	mtx_assert(&kenv_lock, MA_OWNED);
>+	rm_assert(&kenv_lock, RA_LOCKED);
> 	return (_getenv_dynamic_locked(name, idx));
> }
> 
>@@ -501,12 +502,13 @@
> int
> testenv(const char *name)
> {
>+	struct rm_priotracker tracker;
> 	char *cp;
> 
> 	if (dynamic_kenv) {
>-		mtx_lock(&kenv_lock);
>+		rm_rlock(&kenv_lock, &tracker);
> 		cp = _getenv_dynamic(name, NULL);
>-		mtx_unlock(&kenv_lock);
>+		rm_runlock(&kenv_lock, &tracker);
> 	} else
> 		cp = _getenv_static(name);
> 	if (cp != NULL)
>@@ -562,12 +564,12 @@
> 	buf = malloc(namelen + vallen, M_KENV, M_WAITOK);
> 	sprintf(buf, "%s=%s", name, value);
> 
>-	mtx_lock(&kenv_lock);
>+	rm_wlock(&kenv_lock);
> 	cp = _getenv_dynamic(name, &i);
> 	if (cp != NULL) {
> 		oldenv = kenvp[i];
> 		kenvp[i] = buf;
>-		mtx_unlock(&kenv_lock);
>+		rm_wunlock(&kenv_lock);
> 		free(oldenv, M_KENV);
> 	} else {
> 		/* We add the option if it wasn't found */
>@@ -577,13 +579,13 @@
> 		/* Bounds checking */
> 		if (i < 0 || i >= KENV_SIZE) {
> 			free(buf, M_KENV);
>-			mtx_unlock(&kenv_lock);
>+			rm_wunlock(&kenv_lock);
> 			return (-1);
> 		}
> 
> 		kenvp[i] = buf;
> 		kenvp[i + 1] = NULL;
>-		mtx_unlock(&kenv_lock);
>+		rm_wunlock(&kenv_lock);
> 	}
> 	return (0);
> }
>@@ -599,7 +601,7 @@
> 
> 	KENV_CHECK;
> 
>-	mtx_lock(&kenv_lock);
>+	rm_wlock(&kenv_lock);
> 	cp = _getenv_dynamic(name, &i);
> 	if (cp != NULL) {
> 		oldenv = kenvp[i];
>@@ -606,11 +608,11 @@
> 		for (j = i + 1; kenvp[j] != NULL; j++)
> 			kenvp[i++] = kenvp[j];
> 		kenvp[i] = NULL;
>-		mtx_unlock(&kenv_lock);
>+		rm_wunlock(&kenv_lock);
> 		zfree(oldenv, M_KENV);
> 		return (0);
> 	}
>-	mtx_unlock(&kenv_lock);
>+	rm_wunlock(&kenv_lock);
> 	return (-1);
> }
> 
>@@ -620,6 +622,7 @@
> static char *
> getenv_string_buffer(const char *name)
> {
>+	struct rm_priotracker tracker;
> 	char *cp, *ret;
> 	int len;
> 
>@@ -626,11 +629,11 @@
> 	if (dynamic_kenv) {
> 		len = KENV_MNAMELEN + 1 + kenv_mvallen + 1;
> 		ret = uma_zalloc(kenv_zone, M_WAITOK | M_ZERO);
>-		mtx_lock(&kenv_lock);
>+		rm_rlock(&kenv_lock, &tracker);
> 		cp = _getenv_dynamic(name, NULL);
> 		if (cp != NULL)
> 			strlcpy(ret, cp, len);
>-		mtx_unlock(&kenv_lock);
>+		rm_runlock(&kenv_lock, &tracker);
> 		if (cp == NULL) {
> 			uma_zfree(kenv_zone, ret);
> 			ret = NULL;
>@@ -647,14 +650,15 @@
> int
> getenv_string(const char *name, char *data, int size)
> {
>+	struct rm_priotracker tracker;
> 	char *cp;
> 
> 	if (dynamic_kenv) {
>-		mtx_lock(&kenv_lock);
>+		rm_rlock(&kenv_lock, &tracker);
> 		cp = _getenv_dynamic(name, NULL);
> 		if (cp != NULL)
> 			strlcpy(data, cp, size);
>-		mtx_unlock(&kenv_lock);
>+		rm_runlock(&kenv_lock, &tracker);
> 	} else {
> 		cp = _getenv_static(name);
> 		if (cp != NULL)
>@@ -670,19 +674,27 @@
> getenv_array(const char *name, void *pdata, int size, int *psize,
>     int type_size, bool allow_signed)
> {
>+	struct rm_priotracker tracker;
> 	uint8_t shift;
> 	int64_t value;
> 	int64_t old;
>-	char *buf;
>+	const char *buf;
> 	char *end;
>-	char *ptr;
>+	const char *ptr;
> 	int n;
> 	int rc;
> 
>-	if ((buf = getenv_string_buffer(name)) == NULL)
>-		return (0);
>+	if (dynamic_kenv) {
>+		rm_rlock(&kenv_lock, &tracker);
>+		buf = _getenv_dynamic(name, NULL);
>+	} else
>+		buf = _getenv_static(name);
> 
> 	rc = 0;			  /* assume failure */
>+
>+	if (buf == NULL)
>+		goto error;
>+
> 	/* get maximum number of elements */
> 	size /= type_size;
> 
>@@ -798,7 +810,7 @@
> 		rc = 1;	/* success */
> error:
> 	if (dynamic_kenv)
>-		uma_zfree(kenv_zone, buf);
>+		rm_runlock(&kenv_lock, &tracker);
> 	return (rc);
> }
> 
>@@ -898,18 +910,27 @@
> int
> getenv_quad(const char *name, quad_t *data)
> {
>-	char	*value, *vtp;
>-	quad_t	iv;
>+	struct rm_priotracker tracker;
>+	const char	*value;
>+	char		suffix, *vtp;
>+	quad_t		iv;
> 
>-	value = getenv_string_buffer(name);
>-	if (value == NULL)
>-		return (0);
>+	if (dynamic_kenv) {
>+		rm_rlock(&kenv_lock, &tracker);
>+		value = _getenv_dynamic(name, NULL);
>+	} else
>+		value = _getenv_static(name);
>+	if (value == NULL) {
>+		goto error;
>+	}
> 	iv = strtoq(value, &vtp, 0);
> 	if (vtp == value || (vtp[0] != '\0' && vtp[1] != '\0')) {
>-		freeenv(value);
>-		return (0);
>+		goto error;
> 	}
>-	switch (vtp[0]) {
>+	suffix = vtp[0];
>+	if (dynamic_kenv)
>+		rm_runlock(&kenv_lock, &tracker);
>+	switch (suffix) {
> 	case 't': case 'T':
> 		iv *= 1024;
> 		/* FALLTHROUGH */
>@@ -924,12 +945,14 @@
> 	case '\0':
> 		break;
> 	default:
>-		freeenv(value);
> 		return (0);
> 	}
>-	freeenv(value);
> 	*data = iv;
> 	return (1);
>+error:
>+	if (dynamic_kenv)
>+		rm_runlock(&kenv_lock, &tracker);
>+	return (0);
> }
> 
> /*
>Index: sys/kern/subr_hints.c
>===================================================================
>--- sys/kern/subr_hints.c	(revision 363749)
>+++ sys/kern/subr_hints.c	(working copy)
>@@ -33,7 +33,7 @@
> #include <sys/lock.h>
> #include <sys/kernel.h>
> #include <sys/malloc.h>
>-#include <sys/mutex.h>
>+#include <sys/rmlock.h>
> #include <sys/sysctl.h>
> #include <sys/systm.h>
> #include <sys/bus.h>
>@@ -42,6 +42,8 @@
> #define	FBACK_STENV	1	/* Static env */
> #define	FBACK_STATIC	2	/* static_hints */
> 
>+extern struct rmlock kenv_lock;
>+
> /*
>  * We'll use hintenv_merged to indicate that the dynamic environment has been
>  * properly prepared for hint usage.  This implies that the dynamic environment
>@@ -126,6 +128,7 @@
>     const char **ret_name, int *ret_namelen, int *ret_unit,
>     const char **ret_resname, int *ret_resnamelen, const char **ret_value)
> {
>+	struct rm_priotracker tracker; 
> 	int fbacklvl = FBACK_MDENV, i = 0, n = 0;
> 	char r_name[32];
> 	int r_unit;
>@@ -150,7 +153,7 @@
> 			 * already been folded in to the environment
> 			 * by this point.
> 			 */
>-			mtx_lock(&kenv_lock);
>+			rm_rlock(&kenv_lock, &tracker);
> 			cp = kenvp[0];
> 			for (i = 0; cp != NULL; cp = kenvp[++i]) {
> 				if (!strncmp(cp, "hint.", 5)) {
>@@ -158,7 +161,7 @@
> 					break;
> 				}
> 			}
>-			mtx_unlock(&kenv_lock);
>+			rm_runlock(&kenv_lock, &tracker);
> 			dyn_used = true;
> 		} else {
> 			/*
>@@ -224,7 +227,7 @@
> 	}
> 
> 	if (dyn_used) {
>-		mtx_lock(&kenv_lock);
>+		rm_rlock(&kenv_lock, &tracker);
> 		i = 0;
> 	}
> 
>@@ -269,7 +272,7 @@
> 		}
> 	}
> 	if (dyn_used)
>-		mtx_unlock(&kenv_lock);
>+		rm_runlock(&kenv_lock, &tracker);
> 	if (cp == NULL)
> 		goto fallback;
> 
>Index: sys/sys/systm.h
>===================================================================
>--- sys/sys/systm.h	(revision 363749)
>+++ sys/sys/systm.h	(working copy)
>@@ -195,7 +195,6 @@
>  */
> extern int osreldate;
> extern bool dynamic_kenv;
>-extern struct mtx kenv_lock;
> extern char *kern_envp;
> extern char *md_envp;
> extern char static_env[];

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Attachments on bug 248250: 217019 | 217023 | 217024 | 217035 | 217107