firmware: qcom: uefisecapp: Fix memory related IO errors and crashes

commit ed09f81eeaa8f9265e1787282cb283f10285c259 upstream.

It turns out that while the QSEECOM APP_SEND command has specific fields
for request and response buffers, uefisecapp expects them both to be in
a single memory region. Failure to adhere to this has (so far) resulted
in either no response being written to the response buffer (causing an
EIO to be emitted down the line), the SCM call to fail with EINVAL
(i.e., directly from TZ/firmware), or the device to be hard-reset.

While this issue can be triggered deterministically, in the current form
it seems to happen rather sporadically (which is why it has gone
unnoticed during earlier testing). This is likely due to the two
kzalloc() calls (for request and response) being directly after each
other. Which means that those likely return consecutive regions most of
the time, especially when not much else is going on in the system.

Fix this by allocating a single memory region for both request and
response buffers, properly aligning both structs inside it. This
unfortunately also means that the qcom_scm_qseecom_app_send() interface
needs to be restructured, as it should no longer map the DMA regions
separately. Therefore, move the responsibility of DMA allocation (or
mapping) to the caller.

Fixes: 759e7a2b62eb ("firmware: Add support for Qualcomm UEFI Secure Application")
Cc: stable@vger.kernel.org  # 6.7
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Tested-by: Konrad Dybcio <konrad.dybcio@linaro.org> # X13s
Link: https://lore.kernel.org/r/20240406130125.1047436-1-luzmaximilian@gmail.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 5 deletions

diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
index ccaf28846054..aaa19f93ac43 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -118,8 +118,8 @@ bool qcom_scm_lmh_dcvsh_available(void);
 #ifdef CONFIG_QCOM_QSEECOM
 
 int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id);
-int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp,
-			      size_t rsp_size);
+int qcom_scm_qseecom_app_send(u32 app_id, dma_addr_t req, size_t req_size,
+			      dma_addr_t rsp, size_t rsp_size);
 
 #else /* CONFIG_QCOM_QSEECOM */
 
@@ -128,9 +128,9 @@ static inline int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id)
 	return -EINVAL;
 }
 
-static inline int qcom_scm_qseecom_app_send(u32 app_id, void *req,
-					    size_t req_size, void *rsp,
-					    size_t rsp_size)
+static inline int qcom_scm_qseecom_app_send(u32 app_id,
+					    dma_addr_t req, size_t req_size,
+					    dma_addr_t rsp, size_t rsp_size)
 {
 	return -EINVAL;
 }