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author | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-21 16:49:37 +1000 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-25 00:06:55 +1000 |
commit | f47d5a4fc254e62ea5af5cbb2fc3e68901def434 (patch) | |
tree | 123f9ac1f36eca71c45c4d2a8f1bae950f08d51f | |
parent | 3018fbc63632e6d30abde228f29aaeaf78b782bf (diff) | |
download | linux-f47d5a4fc254e62ea5af5cbb2fc3e68901def434.tar.gz linux-f47d5a4fc254e62ea5af5cbb2fc3e68901def434.tar.bz2 linux-f47d5a4fc254e62ea5af5cbb2fc3e68901def434.zip |
powerpc/prom_init: Convert prom_strcpy() into prom_strscpy_pad()
In a subsequent patch we'd like to have something like a strscpy_pad()
implementation usable in prom_init.c.
Currently we have a strcpy() implementation with only one caller, so
convert it into strscpy_pad() and update the caller.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210621064938.2021419-1-mpe@ellerman.id.au
-rw-r--r-- | arch/powerpc/kernel/prom_init.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 523b31685c4c..c18d55f8b951 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -242,13 +242,31 @@ static int __init prom_strcmp(const char *cs, const char *ct) return 0; } -static char __init *prom_strcpy(char *dest, const char *src) +static ssize_t __init prom_strscpy_pad(char *dest, const char *src, size_t n) { - char *tmp = dest; + ssize_t rc; + size_t i; - while ((*dest++ = *src++) != '\0') - /* nothing */; - return tmp; + if (n == 0 || n > INT_MAX) + return -E2BIG; + + // Copy up to n bytes + for (i = 0; i < n && src[i] != '\0'; i++) + dest[i] = src[i]; + + rc = i; + + // If we copied all n then we have run out of space for the nul + if (rc == n) { + // Rewind by one character to ensure nul termination + i--; + rc = -E2BIG; + } + + for (; i < n; i++) + dest[i] = '\0'; + + return rc; } static int __init prom_strncmp(const char *cs, const char *ct, size_t count) @@ -2701,7 +2719,7 @@ 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"); + prom_strscpy_pad(namep, "phandle", sizeof("phandle")); mem_start = (unsigned long)namep + prom_strlen(namep) + 1; /* Build string array */ |