From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- drivers/of/module.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) create mode 100644 drivers/of/module.c (limited to 'drivers/of/module.c') diff --git a/drivers/of/module.c b/drivers/of/module.c new file mode 100644 index 000000000..1e735fc13 --- /dev/null +++ b/drivers/of/module.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Linux kernel module helpers. + */ + +#include +#include +#include +#include + +ssize_t of_modalias(const struct device_node *np, char *str, ssize_t len) +{ + const char *compat; + char *c; + struct property *p; + ssize_t csize; + ssize_t tsize; + + /* + * Prevent a kernel oops in vsnprintf() -- it only allows passing a + * NULL ptr when the length is also 0. Also filter out the negative + * lengths... + */ + if ((len > 0 && !str) || len < 0) + return -EINVAL; + + /* Name & Type */ + /* %p eats all alphanum characters, so %c must be used here */ + csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T', + of_node_get_device_type(np)); + tsize = csize; + if (csize >= len) + csize = len > 0 ? len - 1 : 0; + len -= csize; + str += csize; + + of_property_for_each_string(np, "compatible", p, compat) { + csize = snprintf(str, len, "C%s", compat); + tsize += csize; + if (csize >= len) + continue; + for (c = str; c; ) { + c = strchr(c, ' '); + if (c) + *c++ = '_'; + } + len -= csize; + str += csize; + } + + return tsize; +} + +int of_request_module(const struct device_node *np) +{ + char *str; + ssize_t size; + int ret; + + if (!np) + return -ENODEV; + + size = of_modalias(np, NULL, 0); + if (size < 0) + return size; + + /* Reserve an additional byte for the trailing '\0' */ + size++; + + str = kmalloc(size, GFP_KERNEL); + if (!str) + return -ENOMEM; + + of_modalias(np, str, size); + str[size - 1] = '\0'; + ret = request_module(str); + kfree(str); + + return ret; +} +EXPORT_SYMBOL_GPL(of_request_module); -- cgit v1.3.1