From ce98400f8a9ebd4e62e76b9e292b7598d0d66cc0 Mon Sep 17 00:00:00 2001 From: Marvin Borner Date: Fri, 2 Apr 2021 23:26:28 +0200 Subject: Added kernel section clear/protect after init This is a huge security improvement as it prevents potential exploits of using or modifying internal kernel functions or data. --- libs/libc/Makefile | 1 - libs/libc/alloc.c | 5 -- libs/libc/cpu.c | 182 -------------------------------------------------- libs/libc/inc/cpu.h | 110 ------------------------------ libs/libc/inc/def.h | 9 ++- libs/libc/inc/print.h | 2 +- libs/libc/inc/sys.h | 2 +- libs/libc/print.c | 9 +-- libs/libc/random.c | 5 +- 9 files changed, 16 insertions(+), 309 deletions(-) delete mode 100644 libs/libc/cpu.c delete mode 100644 libs/libc/inc/cpu.h (limited to 'libs') diff --git a/libs/libc/Makefile b/libs/libc/Makefile index d8d58ff..24970d8 100644 --- a/libs/libc/Makefile +++ b/libs/libc/Makefile @@ -10,7 +10,6 @@ COBJS = sanitize.o \ crypto.o \ conv.o \ print.o \ - cpu.o \ sys.o \ list.o \ stack.o \ diff --git a/libs/libc/alloc.c b/libs/libc/alloc.c index 02e30eb..2f8e0ba 100644 --- a/libs/libc/alloc.c +++ b/libs/libc/alloc.c @@ -2,7 +2,6 @@ // Mostly by Durand Miller, released into public domain #include -#include #include #ifdef KERNEL @@ -40,17 +39,13 @@ static int liballoc_free(void *ptr, u32 p) #endif -static u32 locked = 0; - static int liballoc_lock(void) { - spinlock(&locked); return 0; } static int liballoc_unlock(void) { - locked = 0; return 0; } diff --git a/libs/libc/cpu.c b/libs/libc/cpu.c deleted file mode 100644 index 7fbb66a..0000000 --- a/libs/libc/cpu.c +++ /dev/null @@ -1,182 +0,0 @@ -// MIT License, Copyright (c) 2020 Marvin Borner -// This file is a wrapper around some CPU asm calls - -#include -#include -#include - -u8 inb(u16 port) -{ - u8 value; - __asm__ volatile("inb %1, %0" : "=a"(value) : "Nd"(port)); - return value; -} - -u16 inw(u16 port) -{ - u16 value; - __asm__ volatile("inw %1, %0" : "=a"(value) : "Nd"(port)); - return value; -} - -u32 inl(u16 port) -{ - u32 value; - __asm__ volatile("inl %1, %0" : "=a"(value) : "Nd"(port)); - return value; -} - -void insl(u16 port, void *addr, int n) -{ - __asm__ volatile("rep insl" ::"c"(n), // Count - "d"(port), // Port # - "D"(addr)); // Buffer -} - -void outb(u16 port, u8 data) -{ - __asm__ volatile("outb %0, %1" ::"a"(data), "Nd"(port)); -} - -void outw(u16 port, u16 data) -{ - __asm__ volatile("outw %0, %1" ::"a"(data), "Nd"(port)); -} - -void outl(u16 port, u32 data) -{ - __asm__ volatile("outl %0, %1" ::"a"(data), "Nd"(port)); -} - -#ifdef KERNEL - -static void cpuid(int code, u32 *a, u32 *b, u32 *c, u32 *d) -{ - __asm__ volatile("cpuid" : "=a"(*a), "=b"(*b), "=c"(*c), "=d"(*d) : "a"(code)); -} - -static char *cpu_string(char buf[16]) -{ - // wtf - cpuid(CPUID_VENDOR_STRING, (u32 *)(buf + 12), (u32 *)(buf), (u32 *)(buf + 8), - (u32 *)(buf + 4)); - - return buf; -} - -void cpu_print(void) -{ - char buf[16] = { 0 }; - printf("CPU vendor: %s\n", cpu_string(buf)); -} - -u32 cr0_get(void) -{ - u32 cr0; - __asm__ volatile("movl %%cr0, %%eax" : "=a"(cr0)); - return cr0; -} - -void cr0_set(u32 cr0) -{ - __asm__ volatile("movl %%eax, %%cr0" ::"a"(cr0)); -} - -u32 cr3_get(void) -{ - u32 cr3; - __asm__ volatile("movl %%cr0, %%eax" : "=a"(cr3)); - return cr3; -} - -void cr3_set(u32 cr3) -{ - __asm__ volatile("movl %%eax, %%cr3" ::"a"(cr3)); -} - -u32 cr4_get(void) -{ - u32 cr4; - __asm__ volatile("movl %%cr4, %%eax" : "=a"(cr4)); - return cr4; -} - -void cr4_set(u32 cr4) -{ - __asm__ volatile("movl %%eax, %%cr4" ::"a"(cr4)); -} - -static u32 cpu_cfeatures = 0; -u8 cpu_has_cfeature(enum cpuid_features feature) -{ - return (cpu_cfeatures & feature) != 0; -} - -static u32 cpu_dfeatures = 0; -u8 cpu_has_dfeature(enum cpuid_features feature) -{ - return (cpu_dfeatures & feature) != 0; -} - -static void fpu_handler(struct regs *r) -{ - UNUSED(r); - __asm__ volatile("clts"); -} - -static u8 fpu_state[512] ALIGNED(16); -void fpu_restore(void) -{ - __asm__ volatile("fxrstor (%0)" ::"r"(fpu_state)); -} - -void cpu_enable_features(void) -{ - u32 a, b, c, d; - cpuid(CPUID_FEATURES, &a, &b, &c, &d); - cpu_cfeatures = c; - cpu_dfeatures = d; - if (cpu_has_dfeature(CPUID_FEAT_EDX_SSE)) { - cr0_set(cr0_get() & ~(1 << 2)); - cr0_set(cr0_get() | (1 << 1)); - cr4_set(cr4_get() | (3 << 9)); - } else { - panic("No SSE support!\n"); - } - - if (cpu_has_dfeature(CPUID_FEAT_EDX_FPU)) { - __asm__ volatile("fninit"); - __asm__ volatile("fxsave %0" : "=m"(fpu_state)); - irq_install_handler(7, fpu_handler); - } else { - panic("No FPU support!\n"); - } -} - -void cli(void) -{ - __asm__ volatile("cli"); -} - -void sti(void) -{ - __asm__ volatile("sti"); -} - -void hlt(void) -{ - __asm__ volatile("hlt"); -} - -void idle(void) -{ - while (1) - hlt(); -} - -void loop(void) -{ - cli(); - idle(); -} -#endif diff --git a/libs/libc/inc/cpu.h b/libs/libc/inc/cpu.h deleted file mode 100644 index 0410125..0000000 --- a/libs/libc/inc/cpu.h +++ /dev/null @@ -1,110 +0,0 @@ -// MIT License, Copyright (c) 2020 Marvin Borner - -#ifndef CPU_H -#define CPU_H - -#include - -u8 inb(u16 port); -u16 inw(u16 port); -u32 inl(u16 port); -void insl(u16 port, void *addr, int n) ATTR((nonnull(2))); - -void outb(u16 port, u8 data); -void outw(u16 port, u16 data); -void outl(u16 port, u32 data); - -static inline void spinlock(u32 *ptr) -{ - u32 prev; - do - __asm__ volatile("lock xchgl %0,%1" : "=a"(prev) : "m"(*ptr), "a"(1)); - while (prev); -} - -#ifdef KERNEL -void cpu_print(void); -void cpu_enable_features(void); -void fpu_restore(void); - -u32 cr0_get(void); -void cr0_set(u32 cr0); -u32 cr3_get(void); -void cr3_set(u32 cr3); -u32 cr4_get(void); -void cr4_set(u32 cr4); - -void cli(void); -void sti(void); -void hlt(void); -void idle(void); -void loop(void); - -enum cpuid_requests { CPUID_VENDOR_STRING, CPUID_FEATURES, CPUID_TLB, CPUID_SERIAL }; -enum cpuid_features { - CPUID_FEAT_ECX_SSE3 = 1u << 0, - CPUID_FEAT_ECX_PCLMUL = 1u << 1, - CPUID_FEAT_ECX_DTES64 = 1u << 2, - CPUID_FEAT_ECX_MONITOR = 1u << 3, - CPUID_FEAT_ECX_DS_CPL = 1u << 4, - CPUID_FEAT_ECX_VMX = 1u << 5, - CPUID_FEAT_ECX_SMX = 1u << 6, - CPUID_FEAT_ECX_EST = 1u << 7, - CPUID_FEAT_ECX_TM2 = 1u << 8, - CPUID_FEAT_ECX_SSSE3 = 1u << 9, - CPUID_FEAT_ECX_CID = 1u << 10, - CPUID_FEAT_ECX_FMA = 1u << 12, - CPUID_FEAT_ECX_CX16 = 1u << 13, - CPUID_FEAT_ECX_ETPRD = 1u << 14, - CPUID_FEAT_ECX_PDCM = 1u << 15, - CPUID_FEAT_ECX_PCIDE = 1u << 17, - CPUID_FEAT_ECX_DCA = 1u << 18, - CPUID_FEAT_ECX_SSE4_1 = 1u << 19, - CPUID_FEAT_ECX_SSE4_2 = 1u << 20, - CPUID_FEAT_ECX_x2APIC = 1u << 21, - CPUID_FEAT_ECX_MOVBE = 1u << 22, - CPUID_FEAT_ECX_POPCNT = 1u << 23, - CPUID_FEAT_ECX_AES = 1u << 25, - CPUID_FEAT_ECX_XSAVE = 1u << 26, - CPUID_FEAT_ECX_OSXSAVE = 1u << 27, - CPUID_FEAT_ECX_AVX = 1u << 28, - CPUID_FEAT_ECX_F16C = 1u << 29, - CPUID_FEAT_ECX_RDRND = 1u << 30, - - CPUID_FEAT_EDX_FPU = 1u << 0, - CPUID_FEAT_EDX_VME = 1u << 1, - CPUID_FEAT_EDX_DE = 1u << 2, - CPUID_FEAT_EDX_PSE = 1u << 3, - CPUID_FEAT_EDX_TSC = 1u << 4, - CPUID_FEAT_EDX_MSR = 1u << 5, - CPUID_FEAT_EDX_PAE = 1u << 6, - CPUID_FEAT_EDX_MCE = 1u << 7, - CPUID_FEAT_EDX_CX8 = 1u << 8, - CPUID_FEAT_EDX_APIC = 1u << 9, - CPUID_FEAT_EDX_SEP = 1u << 11, - CPUID_FEAT_EDX_MTRR = 1u << 12, - CPUID_FEAT_EDX_PGE = 1u << 13, - CPUID_FEAT_EDX_MCA = 1u << 14, - CPUID_FEAT_EDX_CMOV = 1u << 15, - CPUID_FEAT_EDX_PAT = 1u << 16, - CPUID_FEAT_EDX_PSE36 = 1u << 17, - CPUID_FEAT_EDX_PSN = 1u << 18, - CPUID_FEAT_EDX_CLF = 1u << 19, - CPUID_FEAT_EDX_DTES = 1u << 21, - CPUID_FEAT_EDX_ACPI = 1u << 22, - CPUID_FEAT_EDX_MMX = 1u << 23, - CPUID_FEAT_EDX_FXSR = 1u << 24, - CPUID_FEAT_EDX_SSE = 1u << 25, - CPUID_FEAT_EDX_SSE2 = 1u << 26, - CPUID_FEAT_EDX_SS = 1u << 27, - CPUID_FEAT_EDX_HTT = 1u << 28, - CPUID_FEAT_EDX_TM1 = 1u << 29, - CPUID_FEAT_EDX_IA64 = 1u << 30, -}; - -u8 cpu_has_cfeature(enum cpuid_features feature); -u8 cpu_has_dfeature(enum cpuid_features feature); - -#endif - -#endif diff --git a/libs/libc/inc/def.h b/libs/libc/inc/def.h index 583a351..f1201b9 100644 --- a/libs/libc/inc/def.h +++ b/libs/libc/inc/def.h @@ -23,7 +23,7 @@ typedef unsigned long long u64; * Macros */ -#define UNUSED(__a) ((void)(__a)) +#define UNUSED(a) ((void)(a)) #define MIN(a, b) (((a) < (b)) ? (a) : (b)) #define MAX(a, b) (((a) > (b)) ? (a) : (b)) @@ -32,6 +32,7 @@ typedef unsigned long long u64; #define ATTR __attribute__ #define NORETURN ATTR((noreturn)) +#define NOINLINE ATTR((noinline)) #define DEPRECATED ATTR((deprecated)) #define NONNULL ATTR((nonnull)) #define PURE ATTR((pure)) @@ -44,7 +45,11 @@ typedef unsigned long long u64; #define UNUSED_FUNC ATTR((unused)) #define NO_SANITIZE ATTR((no_sanitize("undefined"))) #define ALIGNED(align) ATTR((aligned(align))) -#define SECTION(section) ATTR((section(section))) + +#ifdef KERNEL +#define CLEAR NOINLINE ATTR((section(".temp_clear"))) +#define PROTECTED ATTR((section(".temp_protect"))) +#endif #define EOF (-1) #define NULL ((void *)0) diff --git a/libs/libc/inc/print.h b/libs/libc/inc/print.h index c0d864e..1d85c33 100644 --- a/libs/libc/inc/print.h +++ b/libs/libc/inc/print.h @@ -17,7 +17,7 @@ NORETURN void panic(const char *format, ...) NONNULL; int vfprintf(const char *path, const char *format, va_list ap) NONNULL; int fprintf(const char *path, const char *format, ...) NONNULL; int log(const char *format, ...) NONNULL; -int err(int code, const char *format, ...) NONNULL; +void err(int code, const char *format, ...) NONNULL; #else #include int print_app(enum stream_defaults id, const char *proc_name, const char *str) NONNULL; diff --git a/libs/libc/inc/sys.h b/libs/libc/inc/sys.h index 81de724..b435899 100644 --- a/libs/libc/inc/sys.h +++ b/libs/libc/inc/sys.h @@ -66,7 +66,7 @@ struct stat { */ void loop(void); -void exit(s32 status); +void exit(s32 status) NORETURN; res read(const char *path, void *buf, u32 offset, u32 count) NONNULL; res write(const char *path, const void *buf, u32 offset, u32 count) NONNULL; res ioctl(const char *path, ...) NONNULL; diff --git a/libs/libc/print.c b/libs/libc/print.c index b77c165..4c38cdc 100644 --- a/libs/libc/print.c +++ b/libs/libc/print.c @@ -3,7 +3,6 @@ #include #include #include -#include #include #include #include @@ -145,7 +144,7 @@ int log(const char *format, ...) return len; } -int err(int code, const char *format, ...) +NORETURN void err(int code, const char *format, ...) { if (errno != EOK) log("ERRNO: %d (%s)\n", errno, strerror(errno)); @@ -154,7 +153,6 @@ int err(int code, const char *format, ...) vfprintf(PATH_ERR, format, ap); va_end(ap); exit(code); - return -1; } int print(const char *str) @@ -251,10 +249,9 @@ NORETURN void panic(const char *format, ...) print("--- DON'T PANIC! ---\n"); print(buf); print_trace(5); - loop(); + while (1) + __asm__ volatile("cli\nhlt"); #else err(1, buf); #endif - while (1) - ; } diff --git a/libs/libc/random.c b/libs/libc/random.c index 5cbbbb6..6e65959 100644 --- a/libs/libc/random.c +++ b/libs/libc/random.c @@ -1,10 +1,13 @@ // MIT License, Copyright (c) 2020 Marvin Borner -#include #include #include #include +#ifdef KERNEL +#include +#endif + static u32 g_seed = 1; void srand(u32 seed) -- cgit v1.2.3