5.15-stable review patch. If anyone has any objections, please let me know.
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From: Yuntao Wang ytcoode@gmail.com
commit 932d8476399f622aa0767a4a0a9e78e5341dc0e1 upstream.
Commit 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage") added a dynamic range for the prepare states, but did not handle the assignment of the dynstate variable in __cpuhp_setup_state_cpuslocked().
This causes the corresponding startup callback not to be invoked when calling __cpuhp_setup_state_cpuslocked() with the CPUHP_BP_PREPARE_DYN parameter, even though it should be.
Currently, the users of __cpuhp_setup_state_cpuslocked(), for one reason or another, have not triggered this bug.
Fixes: 4205e4786d0b ("cpu/hotplug: Provide dynamic range for prepare stage") Signed-off-by: Yuntao Wang ytcoode@gmail.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240515134554.427071-1-ytcoode@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/cpu.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2058,7 +2058,7 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_inst * The caller needs to hold cpus read locked while calling this function. * Return: * On success: - * Positive state number if @state is CPUHP_AP_ONLINE_DYN; + * Positive state number if @state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN; * 0 for all other states * On failure: proper (negative) error code */ @@ -2081,7 +2081,7 @@ int __cpuhp_setup_state_cpuslocked(enum ret = cpuhp_store_callbacks(state, name, startup, teardown, multi_instance);
- dynstate = state == CPUHP_AP_ONLINE_DYN; + dynstate = state == CPUHP_AP_ONLINE_DYN || state == CPUHP_BP_PREPARE_DYN; if (ret > 0 && dynstate) { state = ret; ret = 0; @@ -2112,8 +2112,8 @@ int __cpuhp_setup_state_cpuslocked(enum out: mutex_unlock(&cpuhp_state_mutex); /* - * If the requested state is CPUHP_AP_ONLINE_DYN, return the - * dynamically allocated state in case of success. + * If the requested state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN, + * return the dynamically allocated state in case of success. */ if (!ret && dynstate) return state;