diff options
| author | Juergen Gross <jgross@suse.com> | 2024-07-15 09:47:08 +0200 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2024-07-23 12:23:20 +0200 |
| commit | 368990a7fe30737c990f628a60d26d9854a9e690 (patch) | |
| tree | 3af63590ddc994168d08568094fb7e1637c1e504 /arch/x86/xen/multicalls.c | |
| parent | 9fe6a8c5b247e182c1781556794324a8e26a7cd3 (diff) | |
| download | lwn-368990a7fe30737c990f628a60d26d9854a9e690.tar.gz lwn-368990a7fe30737c990f628a60d26d9854a9e690.zip | |
xen: fix multicall debug data referencing
The recent adding of multicall debug mixed up the referencing of
the debug data. A __percpu tagged pointer can't be initialized with a
plain pointer, so use another percpu variable for the pointer and set
it on each new cpu via a function.
Fixes: 942d917cb92a ("xen: make multicall debug boot time selectable")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407151106.5s7Mnfpz-lkp@intel.com/
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/xen/multicalls.c')
| -rw-r--r-- | arch/x86/xen/multicalls.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index d4cefd8a9af4..10c660fae8b3 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -54,8 +54,9 @@ struct mc_debug_data { static DEFINE_PER_CPU(struct mc_buffer, mc_buffer); static struct mc_debug_data mc_debug_data_early __initdata; -static struct mc_debug_data __percpu *mc_debug_data __refdata = +static DEFINE_PER_CPU(struct mc_debug_data *, mc_debug_data) = &mc_debug_data_early; +static struct mc_debug_data __percpu *mc_debug_data_ptr; DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags); static struct static_key mc_debug __ro_after_init; @@ -70,16 +71,20 @@ static int __init xen_parse_mc_debug(char *arg) } early_param("xen_mc_debug", xen_parse_mc_debug); +void mc_percpu_init(unsigned int cpu) +{ + per_cpu(mc_debug_data, cpu) = per_cpu_ptr(mc_debug_data_ptr, cpu); +} + static int __init mc_debug_enable(void) { - struct mc_debug_data __percpu *mcdb; unsigned long flags; if (!mc_debug_enabled) return 0; - mcdb = alloc_percpu(struct mc_debug_data); - if (!mcdb) { + mc_debug_data_ptr = alloc_percpu(struct mc_debug_data); + if (!mc_debug_data_ptr) { pr_err("xen_mc_debug inactive\n"); static_key_slow_dec(&mc_debug); return -ENOMEM; @@ -88,7 +93,7 @@ static int __init mc_debug_enable(void) /* Be careful when switching to percpu debug data. */ local_irq_save(flags); xen_mc_flush(); - mc_debug_data = mcdb; + mc_percpu_init(0); local_irq_restore(flags); pr_info("xen_mc_debug active\n"); @@ -150,7 +155,7 @@ void xen_mc_flush(void) trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx); if (static_key_false(&mc_debug)) { - mcdb = this_cpu_ptr(mc_debug_data); + mcdb = __this_cpu_read(mc_debug_data); memcpy(mcdb->entries, b->entries, b->mcidx * sizeof(struct multicall_entry)); } @@ -230,7 +235,7 @@ struct multicall_space __xen_mc_entry(size_t args) ret.mc = &b->entries[b->mcidx]; if (static_key_false(&mc_debug)) { - struct mc_debug_data *mcdb = this_cpu_ptr(mc_debug_data); + struct mc_debug_data *mcdb = __this_cpu_read(mc_debug_data); mcdb->caller[b->mcidx] = __builtin_return_address(0); mcdb->argsz[b->mcidx] = args; |