diff options
Diffstat (limited to 'arch/mips/mips-make-current_cpu_data-preempt-safe.patch')
| -rw-r--r-- | arch/mips/mips-make-current_cpu_data-preempt-safe.patch | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/mips/mips-make-current_cpu_data-preempt-safe.patch b/arch/mips/mips-make-current_cpu_data-preempt-safe.patch new file mode 100644 index 00000000..c68b5f46 --- /dev/null +++ b/arch/mips/mips-make-current_cpu_data-preempt-safe.patch @@ -0,0 +1,68 @@ +From 5b2595c3e0dce2912b32ef69aaaacd52cd0e720c Mon Sep 17 00:00:00 2001 +From: Bruce Ashfield <bruce.ashfield@gmail.com> +Date: Fri, 29 Sep 2023 00:11:41 +0000 +Subject: [PATCH] mips: make current_cpu_data preempt safe + +When DEBUG_PREEMPT is enabled, mips/mips64 boots are filled with +backtraces similar to: + + [ 130.730686] BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1 + [ 130.738542] caller is blast_dcache32+0x40/0x190 + [ 130.745908] CPU: 0 PID: 1 Comm: systemd Not tainted 6.4.11-yocto-standard #1 + [ 130.753928] Stack : 0000000000000001 0000000000000000 0000000000000018 9000000004937798 + [ 130.762192] 9000000004937798 90000000049378c8 0000000000000000 0000000000000000 + [ 130.770458] 008fac6060240fea 0000000000014f20 9000000004937728 0000000000000000 + [ 130.778826] 00000000000b61b4 0000000000000030 ffffffff80e8eed0 0000000000000004 + [ 130.787111] 9000000084937577 0000000000000000 0000000000000000 ffffffff810c3b18 + [ 130.795440] ffffffff811f0000 0000000000000000 ffffffff81440000 0000000000000000 + [ 130.803830] 0000000000000000 0000000000000000 ffffffff809842e8 0000000000175097 + [ 130.812272] 0000000000000001 9000000004934000 9000000004937790 c0000000005d9000 + [ 130.820722] ffffffff8010b6fc 0000000000000000 0000000000000000 0000000000000000 + [ 130.829134] 0000000000000000 0000000000000000 ffffffff8010b71c 008fac6060240fea + [ 130.837649] ... + [ 130.845556] Call Trace: + [ 130.853432] [<ffffffff8010b71c>] show_stack+0x64/0x158 + [ 130.861534] [<ffffffff80ea1790>] dump_stack_lvl+0x5c/0x7c + [ 130.869565] [<ffffffff80ea29c4>] check_preemption_disabled+0x10c/0x118 + [ 130.877605] [<ffffffff8012d7c8>] blast_dcache32+0x40/0x190 + [ 130.885585] [<ffffffff8039f648>] __vmalloc_node_range+0x3e0/0x780 + [ 130.893527] [<ffffffff8039fbbc>] vzalloc+0x6c/0x78 + [ 130.901378] [<ffffffff8095d6c4>] n_tty_open+0x1c/0xb8 + [ 130.909252] [<ffffffff8095f5a8>] tty_ldisc_open+0x50/0xd0 + [ 130.917053] [<ffffffff80960150>] tty_ldisc_setup+0x20/0x70 + [ 130.924927] [<ffffffff80958694>] tty_init_dev.part.0+0xbc/0x2c0 + [ 130.932742] [<ffffffff80958da8>] tty_open+0x4b8/0x730 + [ 130.940486] [<ffffffff803e6960>] chrdev_open+0xe0/0x250 + [ 130.948211] [<ffffffff803da7f4>] do_dentry_open+0x274/0x520 + [ 130.955960] [<ffffffff803f642c>] path_openat+0xbc4/0x10d8 + [ 130.963718] [<ffffffff803f7460>] do_filp_open+0x148/0x190 + [ 130.971482] [<ffffffff803dc264>] do_sys_openat2+0xcc/0x1b0 + [ 130.979288] [<ffffffff803dc710>] sys_openat+0x50/0xa8 + [ 130.987077] [<ffffffff80119490>] syscall_common+0x34/0x58 + +We don't control the locking around current_cpu_data, so it cannot use +smp_processor_id() as the cpu index. + +To make ourselves safe in any context, we must use raw_smp_processor_id() + +Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com> +--- + arch/mips/include/asm/cpu-info.h | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h +index a600670d00e9..07f9cddd6c77 100644 +--- a/arch/mips/include/asm/cpu-info.h ++++ b/arch/mips/include/asm/cpu-info.h +@@ -117,7 +117,7 @@ struct cpuinfo_mips { + } __attribute__((aligned(SMP_CACHE_BYTES))); + + extern struct cpuinfo_mips cpu_data[]; +-#define current_cpu_data cpu_data[smp_processor_id()] ++#define current_cpu_data cpu_data[raw_smp_processor_id()] + #define raw_current_cpu_data cpu_data[raw_smp_processor_id()] + #define boot_cpu_data cpu_data[0] + +-- +2.34.1 + |