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| author | Cédric Le Goater <clg@kaod.org> | 2021-01-22 08:50:29 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-01-31 22:35:48 +1100 |
| commit | ed5b00a05c2ae95b59adc3442f45944ec632e794 (patch) | |
| tree | 2a9e35ad4835a06a4d6784695e308adf0aafdfe5 /arch/powerpc/kernel/prom_init.c | |
| parent | 7bd2b120f3fdf8e5c6d9a343517a33c2a5108794 (diff) | |
| download | linux-ed5b00a05c2ae95b59adc3442f45944ec632e794.tar.bz2 | |
powerpc/prom: Fix "ibm,arch-vec-5-platform-support" scan
The "ibm,arch-vec-5-platform-support" property is a list of pairs of
bytes representing the options and values supported by the platform
firmware. At boot time, Linux scans this list and activates the
available features it recognizes : Radix and XIVE.
A recent change modified the number of entries to loop on and 8 bytes,
4 pairs of { options, values } entries are always scanned. This is
fine on KVM but not on PowerVM which can advertises less. As a
consequence on this platform, Linux reads extra entries pointing to
random data, interprets these as available features and tries to
activate them, leading to a firmware crash in
ibm,client-architecture-support.
Fix that by using the property length of "ibm,arch-vec-5-platform-support".
Fixes: ab91239942a9 ("powerpc/prom: Remove VLA in prom_check_platform_support()")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210122075029.797013-1-clg@kaod.org
Diffstat (limited to 'arch/powerpc/kernel/prom_init.c')
| -rw-r--r-- | arch/powerpc/kernel/prom_init.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index e9d4eb6144e1..ccf77b985c8f 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -1331,14 +1331,10 @@ static void __init prom_check_platform_support(void) if (prop_len > sizeof(vec)) prom_printf("WARNING: ibm,arch-vec-5-platform-support longer than expected (len: %d)\n", prop_len); - prom_getprop(prom.chosen, "ibm,arch-vec-5-platform-support", - &vec, sizeof(vec)); - for (i = 0; i < sizeof(vec); i += 2) { - prom_debug("%d: index = 0x%x val = 0x%x\n", i / 2 - , vec[i] - , vec[i + 1]); - prom_parse_platform_support(vec[i], vec[i + 1], - &supported); + prom_getprop(prom.chosen, "ibm,arch-vec-5-platform-support", &vec, sizeof(vec)); + for (i = 0; i < prop_len; i += 2) { + prom_debug("%d: index = 0x%x val = 0x%x\n", i / 2, vec[i], vec[i + 1]); + prom_parse_platform_support(vec[i], vec[i + 1], &supported); } } |