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| author |   Andrew Donnellan <ajd@linux.ibm.com> | 2022-06-14 23:49:52 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2022-06-18 10:19:10 +1000 |
| commit | 7bc08056a6dabc3a1442216daf527edf61ac24b6 (patch) | |
| tree | efeffbfd128740c763008593008a9c9703ff33dd /arch/powerpc/kernel/rtas.c | |
| parent | powerpc: Enable execve syscall exit tracepoint (diff) | |
| download | linux-dev-7bc08056a6dabc3a1442216daf527edf61ac24b6.tar.xz linux-dev-7bc08056a6dabc3a1442216daf527edf61ac24b6.zip | |
powerpc/rtas: Allow ibm,platform-dump RTAS call with null buffer address
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
Diffstat (limited to 'arch/powerpc/kernel/rtas.c')
| -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 a6fce3106e02..693133972294 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1071,7 +1071,7 @@ 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 }, @@ -1120,6 +1120,15 @@ 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; } |