Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Don't taint the kernel if CPUs have different sets of page sizes
supported (other than the one in use).
- Issue I-cache maintenance for module ftrace trampoline.
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: ftrace: Ensure module ftrace trampoline is coherent with I-side
arm64: cpufeature: Don't treat granule sizes as strict
+24
-12
+11
-3
arch/arm64/kernel/cpufeature.c
+11
-3
arch/arm64/kernel/cpufeature.c
···
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};
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static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
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-
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
188
-
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
189
-
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
187
+
/*
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+
* We already refuse to boot CPUs that don't support our configured
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+
* page size, so we can only detect mismatches for a page size other
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+
* than the one we're currently using. Unfortunately, SoCs like this
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+
* exist in the wild so, even though we don't like it, we'll have to go
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+
* along with it and treat them as non-strict.
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+
*/
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+
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
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+
S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
196
+
ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
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+
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ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
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/* Linux shouldn't care about secure memory */
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ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
+13
-9
arch/arm64/kernel/ftrace.c
+13
-9
arch/arm64/kernel/ftrace.c
···
73
73
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74
if (offset < -SZ_128M || offset >= SZ_128M) {
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#ifdef CONFIG_ARM64_MODULE_PLTS
76
-
struct plt_entry trampoline;
76
+
struct plt_entry trampoline, *dst;
77
77
struct module *mod;
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78
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79
/*
···
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* to check if the actual opcodes are in fact identical,
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* regardless of the offset in memory so use memcmp() instead.
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*/
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-
trampoline = get_plt_entry(addr, mod->arch.ftrace_trampoline);
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-
if (memcmp(mod->arch.ftrace_trampoline, &trampoline,
111
-
sizeof(trampoline))) {
112
-
if (plt_entry_is_initialized(mod->arch.ftrace_trampoline)) {
109
+
dst = mod->arch.ftrace_trampoline;
110
+
trampoline = get_plt_entry(addr, dst);
111
+
if (memcmp(dst, &trampoline, sizeof(trampoline))) {
112
+
if (plt_entry_is_initialized(dst)) {
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113
pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n");
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return -EINVAL;
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}
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/* point the trampoline to our ftrace entry point */
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module_disable_ro(mod);
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-
*mod->arch.ftrace_trampoline = trampoline;
119
+
*dst = trampoline;
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120
module_enable_ro(mod, true);
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121
122
-
/* update trampoline before patching in the branch */
123
-
smp_wmb();
122
+
/*
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+
* Ensure updated trampoline is visible to instruction
124
+
* fetch before we patch in the branch.
125
+
*/
126
+
__flush_icache_range((unsigned long)&dst[0],
127
+
(unsigned long)&dst[1]);
124
128
}
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-
addr = (unsigned long)(void *)mod->arch.ftrace_trampoline;
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+
addr = (unsigned long)dst;
126
130
#else /* CONFIG_ARM64_MODULE_PLTS */
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return -EINVAL;
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#endif /* CONFIG_ARM64_MODULE_PLTS */