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From:   Daniel Walker <danielwa@cisco.com>
To:     linuxppc-dev@lists.ozlabs.org, x86@kernel.org,
        Andrew Morton <akpm@linux-foundation.org>
Cc:     Christophe Leroy <christophe.leroy@csgroup.eu>,
        xe-linux-external@cisco.com, Michael Ellerman <mpe@ellerman.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] powerpc: prom_init: switch to early string functions
Date:   Thu, 29 Apr 2021 21:22:15 -0700
Message-Id: <20210430042217.1198052-2-danielwa@cisco.com>
In-Reply-To: <20210430042217.1198052-1-danielwa@cisco.com>
References: <20210430042217.1198052-1-danielwa@cisco.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

This converts the prom_init string users to the early string function
which don't suffer from KASAN or any other debugging enabled.

Cc: xe-linux-external@cisco.com
Signed-off-by: Daniel Walker <danielwa@cisco.com>
---
 arch/powerpc/kernel/prom_init.c        | 185 ++++++-------------------
 arch/powerpc/kernel/prom_init_check.sh |   9 +-
 2 files changed, 51 insertions(+), 143 deletions(-)

diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index ccf77b985c8f..4d4343da1280 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -225,105 +225,6 @@ static bool  __prombss rtas_has_query_cpu_stopped;
 #define PHANDLE_VALID(p)	((p) != 0 && (p) != PROM_ERROR)
 #define IHANDLE_VALID(i)	((i) != 0 && (i) != PROM_ERROR)
 
-/* Copied from lib/string.c and lib/kstrtox.c */
-
-static int __init prom_strcmp(const char *cs, const char *ct)
-{
-	unsigned char c1, c2;
-
-	while (1) {
-		c1 = *cs++;
-		c2 = *ct++;
-		if (c1 != c2)
-			return c1 < c2 ? -1 : 1;
-		if (!c1)
-			break;
-	}
-	return 0;
-}
-
-static char __init *prom_strcpy(char *dest, const char *src)
-{
-	char *tmp = dest;
-
-	while ((*dest++ = *src++) != '\0')
-		/* nothing */;
-	return tmp;
-}
-
-static int __init prom_strncmp(const char *cs, const char *ct, size_t count)
-{
-	unsigned char c1, c2;
-
-	while (count) {
-		c1 = *cs++;
-		c2 = *ct++;
-		if (c1 != c2)
-			return c1 < c2 ? -1 : 1;
-		if (!c1)
-			break;
-		count--;
-	}
-	return 0;
-}
-
-static size_t __init prom_strlen(const char *s)
-{
-	const char *sc;
-
-	for (sc = s; *sc != '\0'; ++sc)
-		/* nothing */;
-	return sc - s;
-}
-
-static int __init prom_memcmp(const void *cs, const void *ct, size_t count)
-{
-	const unsigned char *su1, *su2;
-	int res = 0;
-
-	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
-		if ((res = *su1 - *su2) != 0)
-			break;
-	return res;
-}
-
-static char __init *prom_strstr(const char *s1, const char *s2)
-{
-	size_t l1, l2;
-
-	l2 = prom_strlen(s2);
-	if (!l2)
-		return (char *)s1;
-	l1 = prom_strlen(s1);
-	while (l1 >= l2) {
-		l1--;
-		if (!prom_memcmp(s1, s2, l2))
-			return (char *)s1;
-		s1++;
-	}
-	return NULL;
-}
-
-static size_t __init prom_strlcat(char *dest, const char *src, size_t count)
-{
-	size_t dsize = prom_strlen(dest);
-	size_t len = prom_strlen(src);
-	size_t res = dsize + len;
-
-	/* This would be a bug */
-	if (dsize >= count)
-		return count;
-
-	dest += dsize;
-	count -= dsize;
-	if (len >= count)
-		len = count-1;
-	memcpy(dest, src, len);
-	dest[len] = 0;
-	return res;
-
-}
-
 #ifdef CONFIG_PPC_PSERIES
 static int __init prom_strtobool(const char *s, bool *res)
 {
@@ -694,7 +595,7 @@ static int __init prom_setprop(phandle node, const char *nodename,
 	add_string(&p, tohex((u32)(unsigned long) value));
 	add_string(&p, tohex(valuelen));
 	add_string(&p, tohex(ADDR(pname)));
-	add_string(&p, tohex(prom_strlen(pname)));
+	add_string(&p, tohex(early_strlen(pname)));
 	add_string(&p, "property");
 	*p = 0;
 	return call_prom("interpret", 1, 1, (u32)(unsigned long) cmd);
@@ -779,25 +680,25 @@ static void __init early_cmdline_parse(void)
 		l = prom_getprop(prom.chosen, "bootargs", p, COMMAND_LINE_SIZE-1);
 
 	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) || l <= 0 || p[0] == '\0')
-		prom_strlcat(prom_cmd_line, " " CONFIG_CMDLINE,
+		early_strlcat(prom_cmd_line, " " CONFIG_CMDLINE,
 			     sizeof(prom_cmd_line));
 
 	prom_printf("command line: %s\n", prom_cmd_line);
 
 #ifdef CONFIG_PPC64
-	opt = prom_strstr(prom_cmd_line, "iommu=");
+	opt = early_strstr(prom_cmd_line, "iommu=");
 	if (opt) {
 		prom_printf("iommu opt is: %s\n", opt);
 		opt += 6;
 		while (*opt && *opt == ' ')
 			opt++;
-		if (!prom_strncmp(opt, "off", 3))
+		if (!early_strncmp(opt, "off", 3))
 			prom_iommu_off = 1;
-		else if (!prom_strncmp(opt, "force", 5))
+		else if (!early_strncmp(opt, "force", 5))
 			prom_iommu_force_on = 1;
 	}
 #endif
-	opt = prom_strstr(prom_cmd_line, "mem=");
+	opt = early_strstr(prom_cmd_line, "mem=");
 	if (opt) {
 		opt += 4;
 		prom_memory_limit = prom_memparse(opt, (const char **)&opt);
@@ -809,7 +710,7 @@ static void __init early_cmdline_parse(void)
 
 #ifdef CONFIG_PPC_PSERIES
 	prom_radix_disable = !IS_ENABLED(CONFIG_PPC_RADIX_MMU_DEFAULT);
-	opt = prom_strstr(prom_cmd_line, "disable_radix");
+	opt = early_strstr(prom_cmd_line, "disable_radix");
 	if (opt) {
 		opt += 13;
 		if (*opt && *opt == '=') {
@@ -825,13 +726,13 @@ static void __init early_cmdline_parse(void)
 	if (prom_radix_disable)
 		prom_debug("Radix disabled from cmdline\n");
 
-	opt = prom_strstr(prom_cmd_line, "radix_hcall_invalidate=on");
+	opt = early_strstr(prom_cmd_line, "radix_hcall_invalidate=on");
 	if (opt) {
 		prom_radix_gtse_disable = true;
 		prom_debug("Radix GTSE disabled from cmdline\n");
 	}
 
-	opt = prom_strstr(prom_cmd_line, "xive=off");
+	opt = early_strstr(prom_cmd_line, "xive=off");
 	if (opt) {
 		prom_xive_disable = true;
 		prom_debug("XIVE disabled from cmdline\n");
@@ -839,7 +740,7 @@ static void __init early_cmdline_parse(void)
 #endif /* CONFIG_PPC_PSERIES */
 
 #ifdef CONFIG_PPC_SVM
-	opt = prom_strstr(prom_cmd_line, "svm=");
+	opt = early_strstr(prom_cmd_line, "svm=");
 	if (opt) {
 		bool val;
 
@@ -1199,7 +1100,7 @@ static int __init prom_count_smt_threads(void)
 		type[0] = 0;
 		prom_getprop(node, "device_type", type, sizeof(type));
 
-		if (prom_strcmp(type, "cpu"))
+		if (early_strcmp(type, "cpu"))
 			continue;
 		/*
 		 * There is an entry for each smt thread, each entry being
@@ -1650,7 +1551,7 @@ static void __init prom_init_mem(void)
 			 */
 			prom_getprop(node, "name", type, sizeof(type));
 		}
-		if (prom_strcmp(type, "memory"))
+		if (early_strcmp(type, "memory"))
 			continue;
 
 		plen = prom_getprop(node, "reg", regbuf, sizeof(regbuf));
@@ -1972,19 +1873,19 @@ static void __init prom_initialize_tce_table(void)
 		prom_getprop(node, "device_type", type, sizeof(type));
 		prom_getprop(node, "model", model, sizeof(model));
 
-		if ((type[0] == 0) || (prom_strstr(type, "pci") == NULL))
+		if ((type[0] == 0) || (early_strstr(type, "pci") == NULL))
 			continue;
 
 		/* Keep the old logic intact to avoid regression. */
 		if (compatible[0] != 0) {
-			if ((prom_strstr(compatible, "python") == NULL) &&
-			    (prom_strstr(compatible, "Speedwagon") == NULL) &&
-			    (prom_strstr(compatible, "Winnipeg") == NULL))
+			if ((early_strstr(compatible, "python") == NULL) &&
+			    (early_strstr(compatible, "Speedwagon") == NULL) &&
+			    (early_strstr(compatible, "Winnipeg") == NULL))
 				continue;
 		} else if (model[0] != 0) {
-			if ((prom_strstr(model, "ython") == NULL) &&
-			    (prom_strstr(model, "peedwagon") == NULL) &&
-			    (prom_strstr(model, "innipeg") == NULL))
+			if ((early_strstr(model, "ython") == NULL) &&
+			    (early_strstr(model, "peedwagon") == NULL) &&
+			    (early_strstr(model, "innipeg") == NULL))
 				continue;
 		}
 
@@ -2133,12 +2034,12 @@ static void __init prom_hold_cpus(void)
 
 		type[0] = 0;
 		prom_getprop(node, "device_type", type, sizeof(type));
-		if (prom_strcmp(type, "cpu") != 0)
+		if (early_strcmp(type, "cpu") != 0)
 			continue;
 
 		/* Skip non-configured cpus. */
 		if (prom_getprop(node, "status", type, sizeof(type)) > 0)
-			if (prom_strcmp(type, "okay") != 0)
+			if (early_strcmp(type, "okay") != 0)
 				continue;
 
 		reg = cpu_to_be32(-1); /* make sparse happy */
@@ -2214,9 +2115,9 @@ static void __init prom_find_mmu(void)
 		return;
 	version[sizeof(version) - 1] = 0;
 	/* XXX might need to add other versions here */
-	if (prom_strcmp(version, "Open Firmware, 1.0.5") == 0)
+	if (early_strcmp(version, "Open Firmware, 1.0.5") == 0)
 		of_workarounds = OF_WA_CLAIM;
-	else if (prom_strncmp(version, "FirmWorks,3.", 12) == 0) {
+	else if (early_strncmp(version, "FirmWorks,3.", 12) == 0) {
 		of_workarounds = OF_WA_CLAIM | OF_WA_LONGTRAIL;
 		call_prom("interpret", 1, 1, "dev /memory 0 to allow-reclaim");
 	} else
@@ -2249,7 +2150,7 @@ static void __init prom_init_stdout(void)
 	call_prom("instance-to-path", 3, 1, prom.stdout, path, 255);
 	prom_printf("OF stdout device is: %s\n", of_stdout_device);
 	prom_setprop(prom.chosen, "/chosen", "linux,stdout-path",
-		     path, prom_strlen(path) + 1);
+		     path, early_strlen(path) + 1);
 
 	/* instance-to-package fails on PA-Semi */
 	stdout_node = call_prom("instance-to-package", 1, 1, prom.stdout);
@@ -2259,7 +2160,7 @@ static void __init prom_init_stdout(void)
 		/* If it's a display, note it */
 		memset(type, 0, sizeof(type));
 		prom_getprop(stdout_node, "device_type", type, sizeof(type));
-		if (prom_strcmp(type, "display") == 0)
+		if (early_strcmp(type, "display") == 0)
 			prom_setprop(stdout_node, path, "linux,boot-display", NULL, 0);
 	}
 }
@@ -2280,19 +2181,19 @@ static int __init prom_find_machine_type(void)
 		compat[len] = 0;
 		while (i < len) {
 			char *p = &compat[i];
-			int sl = prom_strlen(p);
+			int sl = early_strlen(p);
 			if (sl == 0)
 				break;
-			if (prom_strstr(p, "Power Macintosh") ||
-			    prom_strstr(p, "MacRISC"))
+			if (early_strstr(p, "Power Macintosh") ||
+			    early_strstr(p, "MacRISC"))
 				return PLATFORM_POWERMAC;
 #ifdef CONFIG_PPC64
 			/* We must make sure we don't detect the IBM Cell
 			 * blades as pSeries due to some firmware issues,
 			 * so we do it here.
 			 */
-			if (prom_strstr(p, "IBM,CBEA") ||
-			    prom_strstr(p, "IBM,CPBW-1.0"))
+			if (early_strstr(p, "IBM,CBEA") ||
+			    early_strstr(p, "IBM,CPBW-1.0"))
 				return PLATFORM_GENERIC;
 #endif /* CONFIG_PPC64 */
 			i += sl + 1;
@@ -2309,7 +2210,7 @@ static int __init prom_find_machine_type(void)
 			   compat, sizeof(compat)-1);
 	if (len <= 0)
 		return PLATFORM_GENERIC;
-	if (prom_strcmp(compat, "chrp"))
+	if (early_strcmp(compat, "chrp"))
 		return PLATFORM_GENERIC;
 
 	/* Default to pSeries. We need to know if we are running LPAR */
@@ -2371,7 +2272,7 @@ static void __init prom_check_displays(void)
 	for (node = 0; prom_next_node(&node); ) {
 		memset(type, 0, sizeof(type));
 		prom_getprop(node, "device_type", type, sizeof(type));
-		if (prom_strcmp(type, "display") != 0)
+		if (early_strcmp(type, "display") != 0)
 			continue;
 
 		/* It seems OF doesn't null-terminate the path :-( */
@@ -2485,9 +2386,9 @@ static unsigned long __init dt_find_string(char *str)
 	s = os = (char *)dt_string_start;
 	s += 4;
 	while (s <  (char *)dt_string_end) {
-		if (prom_strcmp(s, str) == 0)
+		if (early_strcmp(s, str) == 0)
 			return s - os;
-		s += prom_strlen(s) + 1;
+		s += early_strlen(s) + 1;
 	}
 	return 0;
 }
@@ -2520,7 +2421,7 @@ static void __init scan_dt_build_strings(phandle node,
 		}
 
  		/* skip "name" */
-		if (prom_strcmp(namep, "name") == 0) {
+		if (early_strcmp(namep, "name") == 0) {
  			*mem_start = (unsigned long)namep;
  			prev_name = "name";
  			continue;
@@ -2532,7 +2433,7 @@ static void __init scan_dt_build_strings(phandle node,
 			namep = sstart + soff;
 		} else {
 			/* Trim off some if we can */
-			*mem_start = (unsigned long)namep + prom_strlen(namep) + 1;
+			*mem_start = (unsigned long)namep + early_strlen(namep) + 1;
 			dt_string_end = *mem_start;
 		}
 		prev_name = namep;
@@ -2601,7 +2502,7 @@ static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
 			break;
 
  		/* skip "name" */
-		if (prom_strcmp(pname, "name") == 0) {
+		if (early_strcmp(pname, "name") == 0) {
  			prev_name = "name";
  			continue;
  		}
@@ -2632,7 +2533,7 @@ static void __init scan_dt_build_struct(phandle node, unsigned long *mem_start,
 		call_prom("getprop", 4, 1, node, pname, valp, l);
 		*mem_start = ALIGN(*mem_start, 4);
 
-		if (!prom_strcmp(pname, "phandle"))
+		if (!early_strcmp(pname, "phandle"))
 			has_phandle = 1;
 	}
 
@@ -2702,8 +2603,8 @@ static void __init flatten_device_tree(void)
 
 	/* Add "phandle" in there, we'll need it */
 	namep = make_room(&mem_start, &mem_end, 16, 1);
-	prom_strcpy(namep, "phandle");
-	mem_start = (unsigned long)namep + prom_strlen(namep) + 1;
+	early_strcpy(namep, "phandle");
+	mem_start = (unsigned long)namep + early_strlen(namep) + 1;
 
 	/* Build string array */
 	prom_printf("Building dt strings...\n"); 
@@ -3025,7 +2926,7 @@ static void __init fixup_device_tree_efika(void)
 	rv = prom_getprop(node, "model", prop, sizeof(prop));
 	if (rv == PROM_ERROR)
 		return;
-	if (prom_strcmp(prop, "EFIKA5K2"))
+	if (early_strcmp(prop, "EFIKA5K2"))
 		return;
 
 	prom_printf("Applying EFIKA device tree fixups\n");
@@ -3033,13 +2934,13 @@ static void __init fixup_device_tree_efika(void)
 	/* Claiming to be 'chrp' is death */
 	node = call_prom("finddevice", 1, 1, ADDR("/"));
 	rv = prom_getprop(node, "device_type", prop, sizeof(prop));
-	if (rv != PROM_ERROR && (prom_strcmp(prop, "chrp") == 0))
+	if (rv != PROM_ERROR && (early_strcmp(prop, "chrp") == 0))
 		prom_setprop(node, "/", "device_type", "efika", sizeof("efika"));
 
 	/* CODEGEN,description is exposed in /proc/cpuinfo so
 	   fix that too */
 	rv = prom_getprop(node, "CODEGEN,description", prop, sizeof(prop));
-	if (rv != PROM_ERROR && (prom_strstr(prop, "CHRP")))
+	if (rv != PROM_ERROR && (early_strstr(prop, "CHRP")))
 		prom_setprop(node, "/", "CODEGEN,description",
 			     "Efika 5200B PowerPC System",
 			     sizeof("Efika 5200B PowerPC System"));
diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
index b183ab9c5107..bbdeba750d52 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -27,7 +27,14 @@ __secondary_hold_acknowledge __secondary_hold_spinloop __start
 logo_linux_clut224 btext_prepare_BAT
 reloc_got2 kernstart_addr memstart_addr linux_banner _stext
 __prom_init_toc_start __prom_init_toc_end btext_setup_display TOC.
-relocate"
+relocate
+early_strcmp
+early_strcpy
+early_strlcat
+early_strlen
+early_strncmp
+early_strstr
+"
 
 NM="$1"
 OBJ="$2"
-- 
2.25.1