From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- arch/mips/bcm63xx/cs.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) create mode 100644 arch/mips/bcm63xx/cs.c (limited to 'arch/mips/bcm63xx/cs.c') diff --git a/arch/mips/bcm63xx/cs.c b/arch/mips/bcm63xx/cs.c new file mode 100644 index 000000000..29205badc --- /dev/null +++ b/arch/mips/bcm63xx/cs.c @@ -0,0 +1,145 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2008 Maxime Bizon + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static DEFINE_SPINLOCK(bcm63xx_cs_lock); + +/* + * check if given chip select exists + */ +static int is_valid_cs(unsigned int cs) +{ + if (cs > 6) + return 0; + return 1; +} + +/* + * Configure chipselect base address and size (bytes). + * Size must be a power of two between 8k and 256M. + */ +int bcm63xx_set_cs_base(unsigned int cs, u32 base, unsigned int size) +{ + unsigned long flags; + u32 val; + + if (!is_valid_cs(cs)) + return -EINVAL; + + /* sanity check on size */ + if (size != roundup_pow_of_two(size)) + return -EINVAL; + + if (size < 8 * 1024 || size > 256 * 1024 * 1024) + return -EINVAL; + + val = (base & MPI_CSBASE_BASE_MASK); + /* 8k => 0 - 256M => 15 */ + val |= (ilog2(size) - ilog2(8 * 1024)) << MPI_CSBASE_SIZE_SHIFT; + + spin_lock_irqsave(&bcm63xx_cs_lock, flags); + bcm_mpi_writel(val, MPI_CSBASE_REG(cs)); + spin_unlock_irqrestore(&bcm63xx_cs_lock, flags); + + return 0; +} + +EXPORT_SYMBOL(bcm63xx_set_cs_base); + +/* + * configure chipselect timing (ns) + */ +int bcm63xx_set_cs_timing(unsigned int cs, unsigned int wait, + unsigned int setup, unsigned int hold) +{ + unsigned long flags; + u32 val; + + if (!is_valid_cs(cs)) + return -EINVAL; + + spin_lock_irqsave(&bcm63xx_cs_lock, flags); + val = bcm_mpi_readl(MPI_CSCTL_REG(cs)); + val &= ~(MPI_CSCTL_WAIT_MASK); + val &= ~(MPI_CSCTL_SETUP_MASK); + val &= ~(MPI_CSCTL_HOLD_MASK); + val |= wait << MPI_CSCTL_WAIT_SHIFT; + val |= setup << MPI_CSCTL_SETUP_SHIFT; + val |= hold << MPI_CSCTL_HOLD_SHIFT; + bcm_mpi_writel(val, MPI_CSCTL_REG(cs)); + spin_unlock_irqrestore(&bcm63xx_cs_lock, flags); + + return 0; +} + +EXPORT_SYMBOL(bcm63xx_set_cs_timing); + +/* + * configure other chipselect parameter (data bus size, ...) + */ +int bcm63xx_set_cs_param(unsigned int cs, u32 params) +{ + unsigned long flags; + u32 val; + + if (!is_valid_cs(cs)) + return -EINVAL; + + /* none of this fields apply to pcmcia */ + if (cs == MPI_CS_PCMCIA_COMMON || + cs == MPI_CS_PCMCIA_ATTR || + cs == MPI_CS_PCMCIA_IO) + return -EINVAL; + + spin_lock_irqsave(&bcm63xx_cs_lock, flags); + val = bcm_mpi_readl(MPI_CSCTL_REG(cs)); + val &= ~(MPI_CSCTL_DATA16_MASK); + val &= ~(MPI_CSCTL_SYNCMODE_MASK); + val &= ~(MPI_CSCTL_TSIZE_MASK); + val &= ~(MPI_CSCTL_ENDIANSWAP_MASK); + val |= params; + bcm_mpi_writel(val, MPI_CSCTL_REG(cs)); + spin_unlock_irqrestore(&bcm63xx_cs_lock, flags); + + return 0; +} + +EXPORT_SYMBOL(bcm63xx_set_cs_param); + +/* + * set cs status (enable/disable) + */ +int bcm63xx_set_cs_status(unsigned int cs, int enable) +{ + unsigned long flags; + u32 val; + + if (!is_valid_cs(cs)) + return -EINVAL; + + spin_lock_irqsave(&bcm63xx_cs_lock, flags); + val = bcm_mpi_readl(MPI_CSCTL_REG(cs)); + if (enable) + val |= MPI_CSCTL_ENABLE_MASK; + else + val &= ~MPI_CSCTL_ENABLE_MASK; + bcm_mpi_writel(val, MPI_CSCTL_REG(cs)); + spin_unlock_irqrestore(&bcm63xx_cs_lock, flags); + return 0; +} + +EXPORT_SYMBOL(bcm63xx_set_cs_status); -- cgit v1.3.1