From 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 2 Sep 2026 15:31:14 -0700 Subject: treewide: refresh kmalloc_obj() conversions This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook --- arch/x86/boot/cpuflags.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 arch/x86/boot/cpuflags.c (limited to 'arch/x86/boot/cpuflags.c') diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c new file mode 100644 index 000000000..916bac09b --- /dev/null +++ b/arch/x86/boot/cpuflags.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "bitops.h" + +#include +#include +#include "cpuflags.h" + +struct cpu_features cpu; +u32 cpu_vendor[3]; + +static bool loaded_flags; + +static int has_fpu(void) +{ + u16 fcw = -1, fsw = -1; + unsigned long cr0; + + asm volatile("mov %%cr0,%0" : "=r" (cr0)); + if (cr0 & (X86_CR0_EM|X86_CR0_TS)) { + cr0 &= ~(X86_CR0_EM|X86_CR0_TS); + asm volatile("mov %0,%%cr0" : : "r" (cr0)); + } + + asm volatile("fninit ; fnstsw %0 ; fnstcw %1" + : "+m" (fsw), "+m" (fcw)); + + return fsw == 0 && (fcw & 0x103f) == 0x003f; +} + +#ifdef CONFIG_X86_32 +/* + * For building the 16-bit code we want to explicitly specify 32-bit + * push/pop operations, rather than just saying 'pushf' or 'popf' and + * letting the compiler choose. + */ +bool has_eflag(unsigned long mask) +{ + unsigned long f0, f1; + + asm volatile("pushfl \n\t" + "pushfl \n\t" + "pop %0 \n\t" + "mov %0,%1 \n\t" + "xor %2,%1 \n\t" + "push %1 \n\t" + "popfl \n\t" + "pushfl \n\t" + "pop %1 \n\t" + "popfl" + : "=&r" (f0), "=&r" (f1) + : "ri" (mask)); + + return !!((f0^f1) & mask); +} +#endif + +void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d) +{ + asm volatile("cpuid" + : "=a" (*a), "=b" (*b), "=c" (*c), "=d" (*d) + : "0" (id), "2" (count) + ); +} + +#define cpuid(id, a, b, c, d) cpuid_count(id, 0, a, b, c, d) + +void get_cpuflags(void) +{ + u32 max_intel_level, max_amd_level; + u32 tfms; + u32 ignored; + + if (loaded_flags) + return; + loaded_flags = true; + + if (has_fpu()) + set_bit(X86_FEATURE_FPU, cpu.flags); + + if (has_eflag(X86_EFLAGS_ID)) { + cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2], + &cpu_vendor[1]); + + if (max_intel_level >= 0x00000001 && + max_intel_level <= 0x0000ffff) { + cpuid(0x1, &tfms, &ignored, &cpu.flags[4], + &cpu.flags[0]); + cpu.level = (tfms >> 8) & 15; + cpu.family = cpu.level; + cpu.model = (tfms >> 4) & 15; + if (cpu.level >= 6) + cpu.model += ((tfms >> 16) & 0xf) << 4; + } + + if (max_intel_level >= 0x00000007) { + cpuid_count(0x00000007, 0, &ignored, &ignored, + &cpu.flags[16], &ignored); + } + + cpuid(0x80000000, &max_amd_level, &ignored, &ignored, + &ignored); + + if (max_amd_level >= 0x80000001 && + max_amd_level <= 0x8000ffff) { + cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6], + &cpu.flags[1]); + } + } +} -- cgit v1.3.1