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authorAndrew Donnellan <ajd@linux.ibm.com>2022-06-14 15:49:52 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2022-06-18 02:19:10 +0200
commit7bc08056a6dabc3a1442216daf527edf61ac24b6 (patch)
treeefeffbfd128740c763008593008a9c9703ff33dd /arch
parentpowerpc: Enable execve syscall exit tracepoint (diff)
downloadlinux-7bc08056a6dabc3a1442216daf527edf61ac24b6.tar.xz
linux-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')
-rw-r--r--arch/powerpc/kernel/rtas.c11
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;
}