Merge tag 'v5.14-rc4' into media_tree

Linux 5.14-rc4

* tag 'v5.14-rc4': (948 commits)
  Linux 5.14-rc4
  pipe: make pipe writes always wake up readers
  Revert "perf map: Fix dso->nsinfo refcounting"
  mm/memcg: fix NULL pointer dereference in memcg_slab_free_hook()
  slub: fix unreclaimable slab stat for bulk free
  mm/migrate: fix NR_ISOLATED corruption on 64-bit
  mm: memcontrol: fix blocking rstat function called from atomic cgroup1 thresholding code
  ocfs2: issue zeroout to EOF blocks
  ocfs2: fix zero out valid data
  lib/test_string.c: move string selftest in the Runtime Testing menu
  gve: Update MAINTAINERS list
  arch: Kconfig: clean up obsolete use of HAVE_IDE
  can: esd_usb2: fix memory leak
  can: ems_usb: fix memory leak
  can: usb_8dev: fix memory leak
  can: mcba_usb_start(): add missing urb->transfer_dma initialization
  can: hi311x: fix a signedness bug in hi3110_cmd()
  MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver
  scsi: fas216: Fix fall-through warning for Clang
  scsi: acornscsi: Fix fall-through warning for clang
  ...

1 files changed, 25 insertions, 2 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 034ad93a1ad7..b1a5fc04492b 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -32,6 +32,8 @@
 #include <linux/perf_event.h>
 #include <linux/extable.h>
 #include <linux/log2.h>
+
+#include <asm/barrier.h>
 #include <asm/unaligned.h>
 
 /* Registers */
@@ -1377,6 +1379,7 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
 		/* Non-UAPI available opcodes. */
 		[BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
 		[BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
+		[BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
 		[BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
 		[BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
 		[BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
@@ -1621,7 +1624,21 @@ out:
 	COND_JMP(s, JSGE, >=)
 	COND_JMP(s, JSLE, <=)
 #undef COND_JMP
-	/* STX and ST and LDX*/
+	/* ST, STX and LDX*/
+	ST_NOSPEC:
+		/* Speculation barrier for mitigating Speculative Store Bypass.
+		 * In case of arm64, we rely on the firmware mitigation as
+		 * controlled via the ssbd kernel parameter. Whenever the
+		 * mitigation is enabled, it works for all of the kernel code
+		 * with no need to provide any additional instructions here.
+		 * In case of x86, we use 'lfence' insn for mitigation. We
+		 * reuse preexisting logic from Spectre v1 mitigation that
+		 * happens to produce the required code on x86 for v4 as well.
+		 */
+#ifdef CONFIG_X86
+		barrier_nospec();
+#endif
+		CONT;
 #define LDST(SIZEOP, SIZE)						\
 	STX_MEM_##SIZEOP:						\
 		*(SIZE *)(unsigned long) (DST + insn->off) = SRC;	\
@@ -2236,8 +2253,14 @@ static void bpf_prog_free_deferred(struct work_struct *work)
 #endif
 	if (aux->dst_trampoline)
 		bpf_trampoline_put(aux->dst_trampoline);
-	for (i = 0; i < aux->func_cnt; i++)
+	for (i = 0; i < aux->func_cnt; i++) {
+		/* We can just unlink the subprog poke descriptor table as
+		 * it was originally linked to the main program and is also
+		 * released along with it.
+		 */
+		aux->func[i]->aux->poke_tab = NULL;
 		bpf_jit_free(aux->func[i]);
+	}
 	if (aux->func_cnt) {
 		kfree(aux->func);
 		bpf_prog_unlock_free(aux->prog);