Reset the list head after the reallocation because the list syscon_list use allocated pointer and they are no more valid. This patch avoid issue (crash) when syscon_node_to_regmap() is called before and after reallocation.
Signed-off-by: Patrick Delaunay patrick.delaunay@st.com --- Hi
This patch correct a crash see on v2018.11-rc1 with my board stm32mp1 for the command "reset".
The crash is a side effect of 2 patches 1f6ca3f42f6edf143473159297f4c515b1cf36f6 sysreset: syscon: update regmap access to syscon
23471aed5c33e104d6fa64575932577618543bec board_f: Add reset status printing
With the first patch the syscon_node_to_regmap() is called each time that the class sysreset_syscon is probed.
=> in v2018.09 probe is done only when reset is requested
NB: for stm32mp1, the node rcc_reboot in tagged pre-relocated to support reset in pre-reloc phases (allow panic).
With the second patch, U-Boot probes all the sysreset uclass in preloc phase to allow to print the reset status, and the list is initialized in board_f / pre-reloc:
-> print_resetinfo --> uclass_first_device_err(UCLASS_SYSRESET, &dev); ---> syscon_reboot_probe() ----> syscon_node_to_regmap(node) -----> of_syscon_register() -------> list_add_tail(&syscon->list, &syscon_list);
During relocation, the content of syscon_list (static) is updated but the list use pointers allocated by malloc in pre-reloc phasis
And when I execute the reset command -> do_reset() --> reset_cpu() ---> sysreset_walk_halt(SYSRESET_COLD); ----> loop on device UCLASS_SYSRESET -----> syscon_reboot_probe() ------> syscon_node_to_regmap(node) -------> list_for_each_entry(entry, &syscon_list, list)
I have a crash here because the pointer syscon_list.next is invalid.
I solve the issue by resetting the list after reloc and it is working but I don't know if a more elegant solution exist (keep the list in .bss section to be set to 0).
Regards
Patrick
drivers/core/syscon-uclass.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/core/syscon-uclass.c b/drivers/core/syscon-uclass.c index 303e166..aacb43a 100644 --- a/drivers/core/syscon-uclass.c +++ b/drivers/core/syscon-uclass.c @@ -156,8 +156,15 @@ static struct syscon *of_syscon_register(ofnode node)
struct regmap *syscon_node_to_regmap(ofnode node) { + static int reloc_done; struct syscon *entry, *syscon = NULL;
+ /* content of list is not relocated (malloc): reinit when needed */ + if (!reloc_done && (gd->flags & GD_FLG_RELOC)) { + INIT_LIST_HEAD(&syscon_list); + reloc_done++; + } + list_for_each_entry(entry, &syscon_list, list) if (ofnode_equal(entry->node, node)) { syscon = entry;