On Fri, Mar 28, 2025 at 12:50:12PM +0800, Peng Fan wrote: > On Thu, Mar 27, 2025 at 11:46:33AM -0600, Mathieu Poirier wrote: > >Hi, > > > >On Wed, Mar 26, 2025 at 10:02:14AM +0800, Peng Fan (OSS) wrote: > >> From: Peng Fan <peng....@nxp.com> > >> > >> There is case as below could trigger kernel dump: > >> Use U-Boot to start remote processor(rproc) with resource table > >> published to a fixed address by rproc. After Kernel boots up, > >> stop the rproc, load a new firmware which doesn't have resource table > >> ,and start rproc. > >> > > > >If a firwmare image doesn't have a resouce table, rproc_elf_load_rsc_table() > >will return an error [1], rproc_fw_boot() will exit prematurely [2] and the > >remote processor won't be started. What am I missing? > > STM32 and i.MX use their own parse_fw implementation which allows no resource > table: > https://elixir.bootlin.com/linux/v6.13.7/source/drivers/remoteproc/stm32_rproc.c#L272 > https://elixir.bootlin.com/linux/v6.13.7/source/drivers/remoteproc/imx_rproc.c#L598
Ok, that settles rproc_fw_boot() but there is also rproc_find_loaded_rsc_table() that will return NULL if a resource table is not found and preventing the memcpy() in rproc_start() from happening: https://elixir.bootlin.com/linux/v6.14-rc6/source/drivers/remoteproc/remoteproc_core.c#L1288 > > Thanks, > Peng > > > > >[1]. > >https://elixir.bootlin.com/linux/v6.14-rc6/source/drivers/remoteproc/remoteproc_elf_loader.c#L338 > >[2]. > >https://elixir.bootlin.com/linux/v6.14-rc6/source/drivers/remoteproc/remoteproc_core.c#L1411 > > > > > >> When starting rproc with a firmware not have resource table, > >> `memcpy(loaded_table, rproc->cached_table, rproc->table_sz)` will > >> trigger dump, because rproc->cache_table is set to NULL during the last > >> stop operation, but rproc->table_sz is still valid. > >> > >> This issue is found on i.MX8MP and i.MX9. > >> > >> Dump as below: > >> Unable to handle kernel NULL pointer dereference at virtual address > >> 0000000000000000 > >> Mem abort info: > >> ESR = 0x0000000096000004 > >> EC = 0x25: DABT (current EL), IL = 32 bits > >> SET = 0, FnV = 0 > >> EA = 0, S1PTW = 0 > >> FSC = 0x04: level 0 translation fault > >> Data abort info: > >> ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 > >> CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > >> GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > >> user pgtable: 4k pages, 48-bit VAs, pgdp=000000010af63000 > >> [0000000000000000] pgd=0000000000000000, p4d=0000000000000000 > >> Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP > >> Modules linked in: > >> CPU: 2 UID: 0 PID: 1060 Comm: sh Not tainted > >> 6.14.0-rc7-next-20250317-dirty #38 > >> Hardware name: NXP i.MX8MPlus EVK board (DT) > >> pstate: a0000005 (NzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > >> pc : __pi_memcpy_generic+0x110/0x22c > >> lr : rproc_start+0x88/0x1e0 > >> Call trace: > >> __pi_memcpy_generic+0x110/0x22c (P) > >> rproc_boot+0x198/0x57c > >> state_store+0x40/0x104 > >> dev_attr_store+0x18/0x2c > >> sysfs_kf_write+0x7c/0x94 > >> kernfs_fop_write_iter+0x120/0x1cc > >> vfs_write+0x240/0x378 > >> ksys_write+0x70/0x108 > >> __arm64_sys_write+0x1c/0x28 > >> invoke_syscall+0x48/0x10c > >> el0_svc_common.constprop.0+0xc0/0xe0 > >> do_el0_svc+0x1c/0x28 > >> el0_svc+0x30/0xcc > >> el0t_64_sync_handler+0x10c/0x138 > >> el0t_64_sync+0x198/0x19c > >> > >> Clear rproc->table_sz to address the issue. > >> > >> While at here, also clear rproc->table_sz when rproc_fw_boot and > >> rproc_detach. > >> > >> Fixes: 9dc9507f1880 ("remoteproc: Properly deal with the resource table > >> when detaching") > >> Signed-off-by: Peng Fan <peng....@nxp.com> > >> --- > >> > >> V2: > >> Clear table_sz when rproc_fw_boot and rproc_detach per Arnaud > >> > >> drivers/remoteproc/remoteproc_core.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/drivers/remoteproc/remoteproc_core.c > >> b/drivers/remoteproc/remoteproc_core.c > >> index c2cf0d277729..1efa53d4e0c3 100644 > >> --- a/drivers/remoteproc/remoteproc_core.c > >> +++ b/drivers/remoteproc/remoteproc_core.c > >> @@ -1442,6 +1442,7 @@ static int rproc_fw_boot(struct rproc *rproc, const > >> struct firmware *fw) > >> kfree(rproc->cached_table); > >> rproc->cached_table = NULL; > >> rproc->table_ptr = NULL; > >> + rproc->table_sz = 0; > >> unprepare_rproc: > >> /* release HW resources if needed */ > >> rproc_unprepare_device(rproc); > >> @@ -2025,6 +2026,7 @@ int rproc_shutdown(struct rproc *rproc) > >> kfree(rproc->cached_table); > >> rproc->cached_table = NULL; > >> rproc->table_ptr = NULL; > >> + rproc->table_sz = 0; > >> out: > >> mutex_unlock(&rproc->lock); > >> return ret; > >> @@ -2091,6 +2093,7 @@ int rproc_detach(struct rproc *rproc) > >> kfree(rproc->cached_table); > >> rproc->cached_table = NULL; > >> rproc->table_ptr = NULL; > >> + rproc->table_sz = 0; > >> out: > >> mutex_unlock(&rproc->lock); > >> return ret; > >> -- > >> 2.37.1 > >> > >
