From c237094850d33ea4ae93ebb2b04ba2e23adedeb6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 3 Jun 2024 07:08:50 +0200 Subject: Merging upstream version 6.8.12. Signed-off-by: Daniel Baumann --- arch/x86/Kconfig | 8 +++-- arch/x86/boot/compressed/head_64.S | 5 +++ arch/x86/crypto/nh-avx2-x86_64.S | 1 + arch/x86/crypto/sha256-avx2-asm.S | 1 + arch/x86/crypto/sha512-avx2-asm.S | 1 + arch/x86/entry/vsyscall/vsyscall_64.c | 28 ++------------- arch/x86/include/asm/cmpxchg_64.h | 2 +- arch/x86/include/asm/pgtable_types.h | 2 ++ arch/x86/include/asm/processor.h | 1 - arch/x86/include/asm/sparsemem.h | 2 -- arch/x86/kernel/cpu/microcode/amd.c | 2 +- arch/x86/kernel/tsc_sync.c | 6 ++-- arch/x86/lib/x86-opcode-map.txt | 10 +++--- arch/x86/mm/fault.c | 33 +---------------- arch/x86/mm/numa.c | 4 +-- arch/x86/mm/pat/set_memory.c | 68 +++++++++++++++++++++++++++-------- arch/x86/net/bpf_jit_comp.c | 57 +++++++++++++---------------- arch/x86/purgatory/Makefile | 3 +- arch/x86/tools/relocs.c | 9 +++++ 19 files changed, 120 insertions(+), 123 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 6f49999a6b..bfccf12138 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2474,9 +2474,13 @@ menuconfig CPU_MITIGATIONS help Say Y here to enable options which enable mitigations for hardware vulnerabilities (usually related to speculative execution). + Mitigations can be disabled or restricted to SMT systems at runtime + via the "mitigations" kernel parameter. - If you say N, all mitigations will be disabled. You really - should know what you are doing to say so. + If you say N, all mitigations will be disabled. This CANNOT be + overridden at runtime. + + Say 'Y', unless you really know what you are doing. if CPU_MITIGATIONS diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index bf4a10a579..1dcb794c54 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -398,6 +398,11 @@ SYM_CODE_START(startup_64) call sev_enable #endif + /* Preserve only the CR4 bits that must be preserved, and clear the rest */ + movq %cr4, %rax + andl $(X86_CR4_PAE | X86_CR4_MCE | X86_CR4_LA57), %eax + movq %rax, %cr4 + /* * configure_5level_paging() updates the number of paging levels using * a trampoline in 32-bit addressable memory if the current number does diff --git a/arch/x86/crypto/nh-avx2-x86_64.S b/arch/x86/crypto/nh-avx2-x86_64.S index ef73a3ab87..791386d9a8 100644 --- a/arch/x86/crypto/nh-avx2-x86_64.S +++ b/arch/x86/crypto/nh-avx2-x86_64.S @@ -154,5 +154,6 @@ SYM_TYPED_FUNC_START(nh_avx2) vpaddq T1, T0, T0 vpaddq T4, T0, T0 vmovdqu T0, (HASH) + vzeroupper RET SYM_FUNC_END(nh_avx2) diff --git a/arch/x86/crypto/sha256-avx2-asm.S b/arch/x86/crypto/sha256-avx2-asm.S index 9918212faf..0ffb072be9 100644 --- a/arch/x86/crypto/sha256-avx2-asm.S +++ b/arch/x86/crypto/sha256-avx2-asm.S @@ -716,6 +716,7 @@ SYM_TYPED_FUNC_START(sha256_transform_rorx) popq %r13 popq %r12 popq %rbx + vzeroupper RET SYM_FUNC_END(sha256_transform_rorx) diff --git a/arch/x86/crypto/sha512-avx2-asm.S b/arch/x86/crypto/sha512-avx2-asm.S index f08496cd68..24973f42c4 100644 --- a/arch/x86/crypto/sha512-avx2-asm.S +++ b/arch/x86/crypto/sha512-avx2-asm.S @@ -680,6 +680,7 @@ SYM_TYPED_FUNC_START(sha512_transform_rorx) pop %r12 pop %rbx + vzeroupper RET SYM_FUNC_END(sha512_transform_rorx) diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c index e0ca8120ae..1245000a87 100644 --- a/arch/x86/entry/vsyscall/vsyscall_64.c +++ b/arch/x86/entry/vsyscall/vsyscall_64.c @@ -98,11 +98,6 @@ static int addr_to_vsyscall_nr(unsigned long addr) static bool write_ok_or_segv(unsigned long ptr, size_t size) { - /* - * XXX: if access_ok, get_user, and put_user handled - * sig_on_uaccess_err, this could go away. - */ - if (!access_ok((void __user *)ptr, size)) { struct thread_struct *thread = ¤t->thread; @@ -120,10 +115,8 @@ static bool write_ok_or_segv(unsigned long ptr, size_t size) bool emulate_vsyscall(unsigned long error_code, struct pt_regs *regs, unsigned long address) { - struct task_struct *tsk; unsigned long caller; int vsyscall_nr, syscall_nr, tmp; - int prev_sig_on_uaccess_err; long ret; unsigned long orig_dx; @@ -172,8 +165,6 @@ bool emulate_vsyscall(unsigned long error_code, goto sigsegv; } - tsk = current; - /* * Check for access_ok violations and find the syscall nr. * @@ -234,12 +225,8 @@ bool emulate_vsyscall(unsigned long error_code, goto do_ret; /* skip requested */ /* - * With a real vsyscall, page faults cause SIGSEGV. We want to - * preserve that behavior to make writing exploits harder. + * With a real vsyscall, page faults cause SIGSEGV. */ - prev_sig_on_uaccess_err = current->thread.sig_on_uaccess_err; - current->thread.sig_on_uaccess_err = 1; - ret = -EFAULT; switch (vsyscall_nr) { case 0: @@ -262,23 +249,12 @@ bool emulate_vsyscall(unsigned long error_code, break; } - current->thread.sig_on_uaccess_err = prev_sig_on_uaccess_err; - check_fault: if (ret == -EFAULT) { /* Bad news -- userspace fed a bad pointer to a vsyscall. */ warn_bad_vsyscall(KERN_INFO, regs, "vsyscall fault (exploit attempt?)"); - - /* - * If we failed to generate a signal for any reason, - * generate one here. (This should be impossible.) - */ - if (WARN_ON_ONCE(!sigismember(&tsk->pending.signal, SIGBUS) && - !sigismember(&tsk->pending.signal, SIGSEGV))) - goto sigsegv; - - return true; /* Don't emulate the ret. */ + goto sigsegv; } regs->ax = ret; diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h index 44b08b53ab..c1d6cd58f8 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -62,7 +62,7 @@ static __always_inline u128 arch_cmpxchg128_local(volatile u128 *ptr, u128 old, asm volatile(_lock "cmpxchg16b %[ptr]" \ CC_SET(e) \ : CC_OUT(e) (ret), \ - [ptr] "+m" (*ptr), \ + [ptr] "+m" (*(_ptr)), \ "+a" (o.low), "+d" (o.high) \ : "b" (n.low), "c" (n.high) \ : "memory"); \ diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 9abb8cc4cd..b786449626 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -567,6 +567,8 @@ static inline void update_page_count(int level, unsigned long pages) { } extern pte_t *lookup_address(unsigned long address, unsigned int *level); extern pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, unsigned int *level); +pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, + unsigned int *level, bool *nx, bool *rw); extern pmd_t *lookup_pmd_address(unsigned long address); extern phys_addr_t slow_virt_to_phys(void *__address); extern int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 26620d7642..5636ad6973 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -479,7 +479,6 @@ struct thread_struct { unsigned long iopl_emul; unsigned int iopl_warn:1; - unsigned int sig_on_uaccess_err:1; /* * Protection Keys Register for Userspace. Loaded immediately on diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h index 1be13b2dfe..64df897c0e 100644 --- a/arch/x86/include/asm/sparsemem.h +++ b/arch/x86/include/asm/sparsemem.h @@ -37,8 +37,6 @@ extern int phys_to_target_node(phys_addr_t start); #define phys_to_target_node phys_to_target_node extern int memory_add_physaddr_to_nid(u64 start); #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid -extern int numa_fill_memblks(u64 start, u64 end); -#define numa_fill_memblks numa_fill_memblks #endif #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index 13b45b9c80..620f0af713 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -465,7 +465,7 @@ static bool early_apply_microcode(u32 cpuid_1_eax, u32 old_rev, void *ucode, siz return !__apply_microcode_amd(mc); } -static bool get_builtin_microcode(struct cpio_data *cp, unsigned int family) +static bool get_builtin_microcode(struct cpio_data *cp, u8 family) { char fw_name[36] = "amd-ucode/microcode_amd.bin"; struct firmware fw; diff --git a/arch/x86/kernel/tsc_sync.c b/arch/x86/kernel/tsc_sync.c index 1123ef3ccf..4334033658 100644 --- a/arch/x86/kernel/tsc_sync.c +++ b/arch/x86/kernel/tsc_sync.c @@ -193,11 +193,9 @@ bool tsc_store_and_check_tsc_adjust(bool bootcpu) cur->warned = false; /* - * If a non-zero TSC value for socket 0 may be valid then the default - * adjusted value cannot assumed to be zero either. + * The default adjust value cannot be assumed to be zero on any socket. */ - if (tsc_async_resets) - cur->adjusted = bootval; + cur->adjusted = bootval; /* * Check whether this CPU is the first in a package to come up. In diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt index 5168ee0360..d1ccd06c53 100644 --- a/arch/x86/lib/x86-opcode-map.txt +++ b/arch/x86/lib/x86-opcode-map.txt @@ -148,7 +148,7 @@ AVXcode: 65: SEG=GS (Prefix) 66: Operand-Size (Prefix) 67: Address-Size (Prefix) -68: PUSH Iz (d64) +68: PUSH Iz 69: IMUL Gv,Ev,Iz 6a: PUSH Ib (d64) 6b: IMUL Gv,Ev,Ib @@ -698,10 +698,10 @@ AVXcode: 2 4d: vrcp14ss/d Vsd,Hpd,Wsd (66),(ev) 4e: vrsqrt14ps/d Vpd,Wpd (66),(ev) 4f: vrsqrt14ss/d Vsd,Hsd,Wsd (66),(ev) -50: vpdpbusd Vx,Hx,Wx (66),(ev) -51: vpdpbusds Vx,Hx,Wx (66),(ev) -52: vdpbf16ps Vx,Hx,Wx (F3),(ev) | vpdpwssd Vx,Hx,Wx (66),(ev) | vp4dpwssd Vdqq,Hdqq,Wdq (F2),(ev) -53: vpdpwssds Vx,Hx,Wx (66),(ev) | vp4dpwssds Vdqq,Hdqq,Wdq (F2),(ev) +50: vpdpbusd Vx,Hx,Wx (66) +51: vpdpbusds Vx,Hx,Wx (66) +52: vdpbf16ps Vx,Hx,Wx (F3),(ev) | vpdpwssd Vx,Hx,Wx (66) | vp4dpwssd Vdqq,Hdqq,Wdq (F2),(ev) +53: vpdpwssds Vx,Hx,Wx (66) | vp4dpwssds Vdqq,Hdqq,Wdq (F2),(ev) 54: vpopcntb/w Vx,Wx (66),(ev) 55: vpopcntd/q Vx,Wx (66),(ev) 58: vpbroadcastd Vx,Wx (66),(v) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index b01df023de..e604d2d6cc 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -717,39 +717,8 @@ kernelmode_fixup_or_oops(struct pt_regs *regs, unsigned long error_code, WARN_ON_ONCE(user_mode(regs)); /* Are we prepared to handle this kernel fault? */ - if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) { - /* - * Any interrupt that takes a fault gets the fixup. This makes - * the below recursive fault logic only apply to a faults from - * task context. - */ - if (in_interrupt()) - return; - - /* - * Per the above we're !in_interrupt(), aka. task context. - * - * In this case we need to make sure we're not recursively - * faulting through the emulate_vsyscall() logic. - */ - if (current->thread.sig_on_uaccess_err && signal) { - sanitize_error_code(address, &error_code); - - set_signal_archinfo(address, error_code); - - if (si_code == SEGV_PKUERR) { - force_sig_pkuerr((void __user *)address, pkey); - } else { - /* XXX: hwpoison faults will set the wrong code. */ - force_sig_fault(signal, si_code, (void __user *)address); - } - } - - /* - * Barring that, we can do the fixup and be happy. - */ + if (fixup_exception(regs, X86_TRAP_PF, error_code, address)) return; - } /* * AMD erratum #91 manifests as a spurious page fault on a PREFETCH diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index 65e9a6e391..ce84ba86e6 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start) } EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); +#endif + static int __init cmp_memblk(const void *a, const void *b) { const struct numa_memblk *ma = *(const struct numa_memblk **)a; @@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end) } return 0; } - -#endif diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index 135bb594df..b4073fb452 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -619,7 +619,8 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long start, * Validate strict W^X semantics. */ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long start, - unsigned long pfn, unsigned long npg) + unsigned long pfn, unsigned long npg, + bool nx, bool rw) { unsigned long end; @@ -641,6 +642,10 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star if ((pgprot_val(new) & (_PAGE_RW | _PAGE_NX)) != _PAGE_RW) return new; + /* Non-leaf translation entries can disable writing or execution. */ + if (!rw || nx) + return new; + end = start + npg * PAGE_SIZE - 1; WARN_ONCE(1, "CPA detected W^X violation: %016llx -> %016llx range: 0x%016lx - 0x%016lx PFN %lx\n", (unsigned long long)pgprot_val(old), @@ -657,20 +662,26 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star /* * Lookup the page table entry for a virtual address in a specific pgd. - * Return a pointer to the entry and the level of the mapping. + * Return a pointer to the entry, the level of the mapping, and the effective + * NX and RW bits of all page table levels. */ -pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, - unsigned int *level) +pte_t *lookup_address_in_pgd_attr(pgd_t *pgd, unsigned long address, + unsigned int *level, bool *nx, bool *rw) { p4d_t *p4d; pud_t *pud; pmd_t *pmd; *level = PG_LEVEL_NONE; + *nx = false; + *rw = true; if (pgd_none(*pgd)) return NULL; + *nx |= pgd_flags(*pgd) & _PAGE_NX; + *rw &= pgd_flags(*pgd) & _PAGE_RW; + p4d = p4d_offset(pgd, address); if (p4d_none(*p4d)) return NULL; @@ -679,6 +690,9 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, if (p4d_large(*p4d) || !p4d_present(*p4d)) return (pte_t *)p4d; + *nx |= p4d_flags(*p4d) & _PAGE_NX; + *rw &= p4d_flags(*p4d) & _PAGE_RW; + pud = pud_offset(p4d, address); if (pud_none(*pud)) return NULL; @@ -687,6 +701,9 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, if (pud_leaf(*pud) || !pud_present(*pud)) return (pte_t *)pud; + *nx |= pud_flags(*pud) & _PAGE_NX; + *rw &= pud_flags(*pud) & _PAGE_RW; + pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) return NULL; @@ -695,11 +712,26 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, if (pmd_large(*pmd) || !pmd_present(*pmd)) return (pte_t *)pmd; + *nx |= pmd_flags(*pmd) & _PAGE_NX; + *rw &= pmd_flags(*pmd) & _PAGE_RW; + *level = PG_LEVEL_4K; return pte_offset_kernel(pmd, address); } +/* + * Lookup the page table entry for a virtual address in a specific pgd. + * Return a pointer to the entry and the level of the mapping. + */ +pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, + unsigned int *level) +{ + bool nx, rw; + + return lookup_address_in_pgd_attr(pgd, address, level, &nx, &rw); +} + /* * Lookup the page table entry for a virtual address. Return a pointer * to the entry and the level of the mapping. @@ -715,13 +747,16 @@ pte_t *lookup_address(unsigned long address, unsigned int *level) EXPORT_SYMBOL_GPL(lookup_address); static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, - unsigned int *level) + unsigned int *level, bool *nx, bool *rw) { - if (cpa->pgd) - return lookup_address_in_pgd(cpa->pgd + pgd_index(address), - address, level); + pgd_t *pgd; + + if (!cpa->pgd) + pgd = pgd_offset_k(address); + else + pgd = cpa->pgd + pgd_index(address); - return lookup_address(address, level); + return lookup_address_in_pgd_attr(pgd, address, level, nx, rw); } /* @@ -849,12 +884,13 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address, pgprot_t old_prot, new_prot, req_prot, chk_prot; pte_t new_pte, *tmp; enum pg_level level; + bool nx, rw; /* * Check for races, another CPU might have split this page * up already: */ - tmp = _lookup_address_cpa(cpa, address, &level); + tmp = _lookup_address_cpa(cpa, address, &level, &nx, &rw); if (tmp != kpte) return 1; @@ -965,7 +1001,8 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address, new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages, psize, CPA_DETECT); - new_prot = verify_rwx(old_prot, new_prot, lpaddr, old_pfn, numpages); + new_prot = verify_rwx(old_prot, new_prot, lpaddr, old_pfn, numpages, + nx, rw); /* * If there is a conflict, split the large page. @@ -1046,6 +1083,7 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, pte_t *pbase = (pte_t *)page_address(base); unsigned int i, level; pgprot_t ref_prot; + bool nx, rw; pte_t *tmp; spin_lock(&pgd_lock); @@ -1053,7 +1091,7 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, * Check for races, another CPU might have split this page * up for us already: */ - tmp = _lookup_address_cpa(cpa, address, &level); + tmp = _lookup_address_cpa(cpa, address, &level, &nx, &rw); if (tmp != kpte) { spin_unlock(&pgd_lock); return 1; @@ -1594,10 +1632,11 @@ static int __change_page_attr(struct cpa_data *cpa, int primary) int do_split, err; unsigned int level; pte_t *kpte, old_pte; + bool nx, rw; address = __cpa_addr(cpa, cpa->curpage); repeat: - kpte = _lookup_address_cpa(cpa, address, &level); + kpte = _lookup_address_cpa(cpa, address, &level, &nx, &rw); if (!kpte) return __cpa_process_fault(cpa, address, primary); @@ -1619,7 +1658,8 @@ repeat: new_prot = static_protections(new_prot, address, pfn, 1, 0, CPA_PROTECT); - new_prot = verify_rwx(old_prot, new_prot, address, pfn, 1); + new_prot = verify_rwx(old_prot, new_prot, address, pfn, 1, + nx, rw); new_prot = pgprot_clear_protnone_bits(new_prot); diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index df484885cc..f415c2cf53 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1585,36 +1585,41 @@ st: if (is_imm8(insn->off)) if (BPF_MODE(insn->code) == BPF_PROBE_MEM || BPF_MODE(insn->code) == BPF_PROBE_MEMSX) { /* Conservatively check that src_reg + insn->off is a kernel address: - * src_reg + insn->off >= TASK_SIZE_MAX + PAGE_SIZE - * src_reg is used as scratch for src_reg += insn->off and restored - * after emit_ldx if necessary + * src_reg + insn->off > TASK_SIZE_MAX + PAGE_SIZE + * and + * src_reg + insn->off < VSYSCALL_ADDR */ - u64 limit = TASK_SIZE_MAX + PAGE_SIZE; + u64 limit = TASK_SIZE_MAX + PAGE_SIZE - VSYSCALL_ADDR; u8 *end_of_jmp; - /* At end of these emitted checks, insn->off will have been added - * to src_reg, so no need to do relative load with insn->off offset - */ - insn_off = 0; + /* movabsq r10, VSYSCALL_ADDR */ + emit_mov_imm64(&prog, BPF_REG_AX, (long)VSYSCALL_ADDR >> 32, + (u32)(long)VSYSCALL_ADDR); - /* movabsq r11, limit */ - EMIT2(add_1mod(0x48, AUX_REG), add_1reg(0xB8, AUX_REG)); - EMIT((u32)limit, 4); - EMIT(limit >> 32, 4); + /* mov src_reg, r11 */ + EMIT_mov(AUX_REG, src_reg); if (insn->off) { - /* add src_reg, insn->off */ - maybe_emit_1mod(&prog, src_reg, true); - EMIT2_off32(0x81, add_1reg(0xC0, src_reg), insn->off); + /* add r11, insn->off */ + maybe_emit_1mod(&prog, AUX_REG, true); + EMIT2_off32(0x81, add_1reg(0xC0, AUX_REG), insn->off); } - /* cmp src_reg, r11 */ - maybe_emit_mod(&prog, src_reg, AUX_REG, true); - EMIT2(0x39, add_2reg(0xC0, src_reg, AUX_REG)); + /* sub r11, r10 */ + maybe_emit_mod(&prog, AUX_REG, BPF_REG_AX, true); + EMIT2(0x29, add_2reg(0xC0, AUX_REG, BPF_REG_AX)); + + /* movabsq r10, limit */ + emit_mov_imm64(&prog, BPF_REG_AX, (long)limit >> 32, + (u32)(long)limit); + + /* cmp r10, r11 */ + maybe_emit_mod(&prog, AUX_REG, BPF_REG_AX, true); + EMIT2(0x39, add_2reg(0xC0, AUX_REG, BPF_REG_AX)); - /* if unsigned '>=', goto load */ - EMIT2(X86_JAE, 0); + /* if unsigned '>', goto load */ + EMIT2(X86_JA, 0); end_of_jmp = prog; /* xor dst_reg, dst_reg */ @@ -1640,18 +1645,6 @@ st: if (is_imm8(insn->off)) /* populate jmp_offset for JMP above */ start_of_ldx[-1] = prog - start_of_ldx; - if (insn->off && src_reg != dst_reg) { - /* sub src_reg, insn->off - * Restore src_reg after "add src_reg, insn->off" in prev - * if statement. But if src_reg == dst_reg, emit_ldx - * above already clobbered src_reg, so no need to restore. - * If add src_reg, insn->off was unnecessary, no need to - * restore either. - */ - maybe_emit_1mod(&prog, src_reg, true); - EMIT2_off32(0x81, add_1reg(0xE8, src_reg), insn->off); - } - if (!bpf_prog->aux->extable) break; diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile index 08aa0f25f1..8d1c82795e 100644 --- a/arch/x86/purgatory/Makefile +++ b/arch/x86/purgatory/Makefile @@ -42,7 +42,8 @@ KCOV_INSTRUMENT := n # make up the standalone purgatory.ro PURGATORY_CFLAGS_REMOVE := -mcmodel=kernel -PURGATORY_CFLAGS := -mcmodel=large -ffreestanding -fno-zero-initialized-in-bss -g0 +PURGATORY_CFLAGS := -mcmodel=small -ffreestanding -fno-zero-initialized-in-bss -g0 +PURGATORY_CFLAGS += -fpic -fvisibility=hidden PURGATORY_CFLAGS += $(DISABLE_STACKLEAK_PLUGIN) -DDISABLE_BRANCH_PROFILING PURGATORY_CFLAGS += -fno-stack-protector diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index b029fb81eb..e7a44a7f61 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -746,6 +746,15 @@ static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { continue; } + + /* + * Do not perform relocations in .notes sections; any + * values there are meant for pre-boot consumption (e.g. + * startup_xen). + */ + if (sec_applies->shdr.sh_type == SHT_NOTE) + continue; + sh_symtab = sec_symtab->symtab; sym_strtab = sec_symtab->link->strtab; for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { -- cgit v1.2.3