0
0
mirror of https://git.openwrt.org/openwrt/openwrt.git synced 2024-11-22 04:56:15 +00:00
openwrt/target/linux/bcm27xx/patches-6.6/950-0375-random-do-not-use-jump-labels-before-they-are-initia.patch
Álvaro Fernández Rojas 8c405cdccc bcm27xx: add 6.6 kernel patches
The patches were generated from the RPi repo with the following command:
git format-patch v6.6.34..rpi-6.1.y

Some patches needed rebasing and, as usual, the applied and reverted, wireless
drivers, Github workflows, READMEs and defconfigs patches were removed.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2024-06-18 18:52:49 +02:00

87 lines
3.8 KiB
Diff

From db52a5df2f28a98b7eae1fc4a846343d83ee3f1f Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 7 Jun 2022 12:02:10 +0200
Subject: [PATCH 0375/1085] random: do not use jump labels before they are
initialized
[ I would like to pursue fixing this more directly first before actually
merging this, but I thought I'd send this to the list now anyway as a
the "backup" plan. If I can't figure out how to make headway on the
main plan in the next few days, it'll be easy to just do this. ]
Stephen reported that a static key warning splat appears during early
boot on systems that credit randomness from device trees that contain an
"rng-seed" property, because because setup_machine_fdt() is called
before jump_label_init() during setup_arch():
static_key_enable_cpuslocked(): static key '0xffffffe51c6fcfc0' used before call to jump_label_init()
WARNING: CPU: 0 PID: 0 at kernel/jump_label.c:166 static_key_enable_cpuslocked+0xb0/0xb8
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.18.0+ #224 44b43e377bfc84bc99bb5ab885ff694984ee09ff
pstate: 600001c9 (nZCv dAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : static_key_enable_cpuslocked+0xb0/0xb8
lr : static_key_enable_cpuslocked+0xb0/0xb8
sp : ffffffe51c393cf0
x29: ffffffe51c393cf0 x28: 000000008185054c x27: 00000000f1042f10
x26: 0000000000000000 x25: 00000000f10302b2 x24: 0000002513200000
x23: 0000002513200000 x22: ffffffe51c1c9000 x21: fffffffdfdc00000
x20: ffffffe51c2f0831 x19: ffffffe51c6fcfc0 x18: 00000000ffff1020
x17: 00000000e1e2ac90 x16: 00000000000000e0 x15: ffffffe51b710708
x14: 0000000000000066 x13: 0000000000000018 x12: 0000000000000000
x11: 0000000000000000 x10: 00000000ffffffff x9 : 0000000000000000
x8 : 0000000000000000 x7 : 61632065726f6665 x6 : 6220646573752027
x5 : ffffffe51c641d25 x4 : ffffffe51c13142c x3 : ffff0a00ffffff05
x2 : 40000000ffffe003 x1 : 00000000000001c0 x0 : 0000000000000065
Call trace:
static_key_enable_cpuslocked+0xb0/0xb8
static_key_enable+0x2c/0x40
crng_set_ready+0x24/0x30
execute_in_process_context+0x80/0x90
_credit_init_bits+0x100/0x154
add_bootloader_randomness+0x64/0x78
early_init_dt_scan_chosen+0x140/0x184
early_init_dt_scan_nodes+0x28/0x4c
early_init_dt_scan+0x40/0x44
setup_machine_fdt+0x7c/0x120
setup_arch+0x74/0x1d8
start_kernel+0x84/0x44c
__primary_switched+0xc0/0xc8
---[ end trace 0000000000000000 ]---
random: crng init done
Machine model: Google Lazor (rev1 - 2) with LTE
A trivial fix went in to address this on arm64, 73e2d827a501 ("arm64:
Initialize jump labels before setup_machine_fdt()"). But it appears that
fixing it on other platforms might not be so trivial. Instead, defer the
setting of the static branch until later in the boot process.
Fixes: f5bda35fba61 ("random: use static branch for crng_ready()")
Reported-by: Stephen Boyd <swboyd@chromium.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
drivers/char/random.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -843,6 +843,14 @@ void __init random_init_early(const char
unsigned long entropy[BLAKE2S_BLOCK_SIZE / sizeof(long)];
size_t i, longs, arch_bits;
+ /*
+ * If we were initialized by the bootloader before jump labels are
+ * initialized, then we should enable the static branch here, where
+ * it's guaranteed that jump labels have been initialized.
+ */
+ if (!static_branch_likely(&crng_is_ready) && crng_init >= CRNG_READY)
+ crng_set_ready(NULL);
+
#if defined(LATENT_ENTROPY_PLUGIN)
static const u8 compiletime_seed[BLAKE2S_BLOCK_SIZE] __initconst __latent_entropy;
_mix_pool_bytes(compiletime_seed, sizeof(compiletime_seed));