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| author | Andrew Donnellan <ajd@linux.ibm.com> | 2022-06-14 23:49:52 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-29 09:03:30 +0200 |
| commit | c1cfae46c5dc1d450defc5b31dd8d90ab4f46f8d (patch) | |
| tree | ac0932be89f8903e56f63695b68f0244a8c81544 | |
| parent | fe643b5afde63936c5ff97806f15d87cae87e8cc (diff) | |
| download | linux-c1cfae46c5dc1d450defc5b31dd8d90ab4f46f8d.tar.gz linux-c1cfae46c5dc1d450defc5b31dd8d90ab4f46f8d.tar.bz2 linux-c1cfae46c5dc1d450defc5b31dd8d90ab4f46f8d.zip | |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
commit 7bc08056a6dabc3a1442216daf527edf61ac24b6 upstream.
Add a special case to block_rtas_call() to allow the ibm,platform-dump RTAS
call through the RTAS filter if the buffer address is 0.
According to PAPR, ibm,platform-dump is called with a null buffer address
to notify the platform firmware that processing of a particular dump is
finished.
Without this, on a pseries machine with CONFIG_PPC_RTAS_FILTER enabled, an
application such as rtas_errd that is attempting to retrieve a dump will
encounter an error at the end of the retrieval process.
Fixes: bd59380c5ba4 ("powerpc/rtas: Restrict RTAS requests from userspace")
Cc: stable@vger.kernel.org
Reported-by: Sathvika Vasireddy <sathvika@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220614134952.156010-1-ajd@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 3f5814037035..e8f44084d251 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -983,7 +983,7 @@ static struct rtas_filter rtas_filters[] __ro_after_init = { { "get-time-of-day", -1, -1, -1, -1, -1 }, { "ibm,get-vpd", -1, 0, -1, 1, 2 }, { "ibm,lpar-perftools", -1, 2, 3, -1, -1 }, - { "ibm,platform-dump", -1, 4, 5, -1, -1 }, + { "ibm,platform-dump", -1, 4, 5, -1, -1 }, /* Special cased */ { "ibm,read-slot-reset-state", -1, -1, -1, -1, -1 }, { "ibm,scan-log-dump", -1, 0, 1, -1, -1 }, { "ibm,set-dynamic-indicator", -1, 2, -1, -1, -1 }, @@ -1032,6 +1032,15 @@ static bool block_rtas_call(int token, int nargs, size = 1; end = base + size - 1; + + /* + * Special case for ibm,platform-dump - NULL buffer + * address is used to indicate end of dump processing + */ + if (!strcmp(f->name, "ibm,platform-dump") && + base == 0) + return false; + if (!in_rmo_buf(base, end)) goto err; } |