[PATCH 2/3] powerpc: prom_init: switch to early string functions

From: Daniel Walker
Date: Fri Apr 30 2021 - 00:22:27 EST

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@xxxxxxxxx
Signed-off-by: Daniel Walker <danielwa@xxxxxxxxx>
---
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