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| author |   Gustav Wiklander <gustavwi@axis.com> | 2020-09-08 17:11:29 +0200 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2020-09-09 15:11:43 +0100 |
| commit | b59a7ca15464c78ea1ba3b280cfc5ac5ece11ade (patch) | |
| tree | 89bf97bed1b2b9c004656385f622a583f277c02e /drivers/spi/spi.c | |
| parent | spi: spi-cadence-quadspi: Fix mapping of buffers for DMA reads (diff) | |
| download | wireguard-linux-b59a7ca15464c78ea1ba3b280cfc5ac5ece11ade.tar.xz wireguard-linux-b59a7ca15464c78ea1ba3b280cfc5ac5ece11ade.zip | |
spi: Fix memory leak on splited transfers
In the prepare_message callback the bus driver has the
opportunity to split a transfer into smaller chunks.
spi_map_msg is done after prepare_message.
Function spi_res_release releases the splited transfers
in the message. Therefore spi_res_release should be called
after spi_map_msg.
The previous try at this was commit c9ba7a16d0f1
which released the splited transfers after
spi_finalize_current_message had been called.
This introduced a race since the message struct could be
out of scope because the spi_sync call got completed.
Fixes this leak on spi bus driver spi-bcm2835.c when transfer
size is greater than 65532:
Kmemleak:
sg_alloc_table+0x28/0xc8
spi_map_buf+0xa4/0x300
__spi_pump_messages+0x370/0x748
__spi_sync+0x1d4/0x270
spi_sync+0x34/0x58
spi_test_execute_msg+0x60/0x340 [spi_loopback_test]
spi_test_run_iter+0x548/0x578 [spi_loopback_test]
spi_test_run_test+0x94/0x140 [spi_loopback_test]
spi_test_run_tests+0x150/0x180 [spi_loopback_test]
spi_loopback_test_probe+0x50/0xd0 [spi_loopback_test]
spi_drv_probe+0x84/0xe0
Signed-off-by: Gustav Wiklander <gustavwi@axis.com>
Link: https://lore.kernel.org/r/20200908151129.15915-1-gustav.wiklander@axis.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | drivers/spi/spi.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 92b8fb416dca..832926b27c92 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1327,8 +1327,6 @@ out: if (msg->status && ctlr->handle_err) ctlr->handle_err(ctlr, msg); - spi_res_release(ctlr, msg); - spi_finalize_current_message(ctlr); return ret; @@ -1727,6 +1725,13 @@ void spi_finalize_current_message(struct spi_controller *ctlr) spi_unmap_msg(ctlr, mesg); + /* In the prepare_messages callback the spi bus has the opportunity to + * split a transfer to smaller chunks. + * Release splited transfers here since spi_map_msg is done on the + * splited transfers. + */ + spi_res_release(ctlr, mesg); + if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { ret = ctlr->unprepare_message(ctlr, mesg); if (ret) { |