Linus,
please pull the latest x86-urgent-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
x86-urgent-for-linus
An unfortunately larger set of fixes, but a large portion is
selftests. Part of that pull-request was already sent with the core pull
request because we had to merge pieces for dependency resolution.
- Fix the missing clusterid initializaiton for x2apic cluster management
which caused boot failures due to IPIs being sent to the wrong cluster
- Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat task
- Wrap access to __supported_pte_mask in __startup_64() where clang
compile fails due to a non PC relative access being generated.
- Two fixes for 5 level paging fallout in the decompressor: Handle GOT
correctly for paging_prepare() and cleanup_trampoline(). Fix the page
table handling in cleanup_trampoline() to avoid page table corruption.
- Stop special casing protection key 0 as this is inconsistent with the
manpage and also inconsistent with the allocation map handling.
- Override the protection key wen moving away from PROT_EXEC to prevent
inaccessible memory.
- Fix and update the protection key selftests to address breakage and to
cover the above issue
- Add a MOV SS self test
The bits already contained in the core pull request:
- Unbreak the BPF compilation which got broken by the unconditional
requirement of asm-goto, which is not supported by clang.
- Prevent probing on exception masking instructions in uprobes and kprobes
to avoid the issues of the delayed exceptions instead of having an ugly
workaround.
- Prevent a double free_page() in the error path of do_kexec_load()
- Header sync for tools.
Thanks,
tglx
------------------>
Alexander Potapenko (1):
x86/boot/64/clang: Use fixup_pointer() to access '__supported_pte_mask'
Alexei Starovoitov (1):
x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation
Andy Lutomirski (1):
x86/selftests: Add mov_to_ss test
Dave Hansen (13):
x86/pkeys/selftests: Give better unexpected fault error messages
x86/pkeys/selftests: Stop using assert()
x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal
x86/pkeys/selftests: Avoid printf-in-signal deadlocks
x86/pkeys/selftests: Allow faults on unknown keys
x86/pkeys/selftests: Factor out "instruction page"
x86/pkeys/selftests: Add PROT_EXEC test
x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
x86/pkeys: Override pkey when moving away from PROT_EXEC
x86/pkeys/selftests: Fix pointer math
x86/pkeys/selftests: Save off 'prot' for allocations
x86/pkeys/selftests: Add a test for pkey 0
x86/pkeys: Do not special case protection key 0
Dmitry Safonov (1):
x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
Ingo Molnar (3):
objtool, kprobes/x86: Sync the latest <asm/insn.h> header with
tools/objtool/arch/x86/include/asm/insn.h
x86/pkeys/selftests: Adjust the self-test to fresh distros that export
the pkeys ABI
x86/mpx/selftests: Adjust the self-test to fresh distros that export the
MPX ABI
Kirill A. Shutemov (2):
x86/boot/compressed/64: Set up GOT for paging_prepare() and
cleanup_trampoline()
x86/boot/compressed/64: Fix moving page table out of trampoline memory
Masami Hiramatsu (2):
kprobes/x86: Prohibit probing on exception masking instructions
uprobes/x86: Prohibit probing on MOV SS instruction
Tetsuo Handa (1):
x86/kexec: Avoid double free_page() upon do_kexec_load() failure
Thomas Gleixner (1):
x86/apic/x2apic: Initialize cluster ID properly
arch/x86/boot/compressed/head_64.S | 79 +++++--
arch/x86/boot/compressed/pgtable_64.c | 14 +-
arch/x86/include/asm/cpufeature.h | 15 ++
arch/x86/include/asm/insn.h | 18 ++
arch/x86/include/asm/mmu_context.h | 2 +-
arch/x86/include/asm/pkeys.h | 18 +-
arch/x86/kernel/apic/x2apic_cluster.c | 1 +
arch/x86/kernel/head64.c | 10 +-
arch/x86/kernel/kprobes/core.c | 4 +
arch/x86/kernel/machine_kexec_32.c | 6 +-
arch/x86/kernel/machine_kexec_64.c | 5 +-
arch/x86/kernel/process_64.c | 1 +
arch/x86/kernel/uprobes.c | 4 +
arch/x86/mm/pkeys.c | 21 +-
samples/bpf/Makefile | 2 +-
tools/objtool/arch/x86/include/asm/insn.h | 18 ++
tools/testing/selftests/x86/Makefile | 2 +-
tools/testing/selftests/x86/mov_ss_trap.c | 285 ++++++++++++++++++++++++++
tools/testing/selftests/x86/mpx-mini-test.c | 7 +-
tools/testing/selftests/x86/pkey-helpers.h | 20 +-
tools/testing/selftests/x86/protection_keys.c | 254 ++++++++++++++++-------
21 files changed, 654 insertions(+), 132 deletions(-)
create mode 100644 tools/testing/selftests/x86/mov_ss_trap.c
diff --git a/arch/x86/boot/compressed/head_64.S
b/arch/x86/boot/compressed/head_64.S
index fca012baba19..8169e8b7a4dc 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -305,6 +305,25 @@ ENTRY(startup_64)
/* Set up the stack */
leaq boot_stack_end(%rbx), %rsp
+ /*
+ * paging_prepare() and cleanup_trampoline() below can have GOT
+ * references. Adjust the table with address we are running at.
+ *
+ * Zero RAX for adjust_got: the GOT was not adjusted before;
+ * there's no adjustment to undo.
+ */
+ xorq %rax, %rax
+
+ /*
+ * Calculate the address the binary is loaded at and use it as
+ * a GOT adjustment.
+ */
+ call 1f
+1: popq %rdi
+ subq $1b, %rdi
+
+ call adjust_got
+
/*
* At this point we are in long mode with 4-level paging enabled,
* but we might want to enable 5-level paging or vice versa.
@@ -370,10 +389,14 @@ trampoline_return:
/*
* cleanup_trampoline() would restore trampoline memory.
*
+ * RDI is address of the page table to use instead of page table
+ * in trampoline memory (if required).
+ *
* RSI holds real mode data and needs to be preserved across
* this function call.
*/
pushq %rsi
+ leaq top_pgtable(%rbx), %rdi
call cleanup_trampoline
popq %rsi
@@ -381,6 +404,21 @@ trampoline_return:
pushq $0
popfq
+ /*
+ * Previously we've adjusted the GOT with address the binary was
+ * loaded at. Now we need to re-adjust for relocation address.
+ *
+ * Calculate the address the binary is loaded at, so that we can
+ * undo the previous GOT adjustment.
+ */
+ call 1f
+1: popq %rax
+ subq $1b, %rax
+
+ /* The new adjustment is the relocation address */
+ movq %rbx, %rdi
+ call adjust_got
+
/*
* Copy the compressed kernel to the end of our buffer
* where decompression in place becomes safe.
@@ -481,19 +519,6 @@ relocated:
shrq $3, %rcx
rep stosq
-/*
- * Adjust our own GOT
- */
- leaq _got(%rip), %rdx
- leaq _egot(%rip), %rcx
-1:
- cmpq %rcx, %rdx
- jae 2f
- addq %rbx, (%rdx)
- addq $8, %rdx
- jmp 1b
-2:
-
/*
* Do the extraction, and jump to the new kernel..
*/
@@ -512,6 +537,27 @@ relocated:
*/
jmp *%rax
+/*
+ * Adjust the global offset table
+ *
+ * RAX is the previous adjustment of the table to undo (use 0 if it's the
+ * first time we touch GOT).
+ * RDI is the new adjustment to apply.
+ */
+adjust_got:
+ /* Walk through the GOT adding the address to the entries */
+ leaq _got(%rip), %rdx
+ leaq _egot(%rip), %rcx
+1:
+ cmpq %rcx, %rdx
+ jae 2f
+ subq %rax, (%rdx) /* Undo previous adjustment */
+ addq %rdi, (%rdx) /* Apply the new adjustment */
+ addq $8, %rdx
+ jmp 1b
+2:
+ ret
+
.code32
/*
* This is the 32-bit trampoline that will be copied over to low memory.
@@ -649,3 +695,10 @@ boot_stack_end:
.balign 4096
pgtable:
.fill BOOT_PGT_SIZE, 1, 0
+
+/*
+ * The page table is going to be used instead of page table in the trampoline
+ * memory.
+ */
+top_pgtable:
+ .fill PAGE_SIZE, 1, 0
diff --git a/arch/x86/boot/compressed/pgtable_64.c
b/arch/x86/boot/compressed/pgtable_64.c
index 32af1cbcd903..a362fa0b849c 100644
--- a/arch/x86/boot/compressed/pgtable_64.c
+++ b/arch/x86/boot/compressed/pgtable_64.c
@@ -22,14 +22,6 @@ struct paging_config {
/* Buffer to preserve trampoline memory */
static char trampoline_save[TRAMPOLINE_32BIT_SIZE];
-/*
- * The page table is going to be used instead of page table in the trampoline
- * memory.
- *
- * It must not be in BSS as BSS is cleared after cleanup_trampoline().
- */
-static char top_pgtable[PAGE_SIZE] __aligned(PAGE_SIZE) __section(.data);
-
/*
* Trampoline address will be printed by extract_kernel() for debugging
* purposes.
@@ -134,7 +126,7 @@ struct paging_config paging_prepare(void)
return paging_config;
}
-void cleanup_trampoline(void)
+void cleanup_trampoline(void *pgtable)
{
void *trampoline_pgtable;
@@ -145,8 +137,8 @@ void cleanup_trampoline(void)
* if it's there.
*/
if ((void *)__native_read_cr3() == trampoline_pgtable) {
- memcpy(top_pgtable, trampoline_pgtable, PAGE_SIZE);
- native_write_cr3((unsigned long)top_pgtable);
+ memcpy(pgtable, trampoline_pgtable, PAGE_SIZE);
+ native_write_cr3((unsigned long)pgtable);
}
/* Restore trampoline memory */
diff --git a/arch/x86/include/asm/cpufeature.h
b/arch/x86/include/asm/cpufeature.h
index b27da9602a6d..aced6c9290d6 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -140,6 +140,20 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned
int bit);
#define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)
+#if defined(__clang__) && !defined(CC_HAVE_ASM_GOTO)
+
+/*
+ * Workaround for the sake of BPF compilation which utilizes kernel
+ * headers, but clang does not support ASM GOTO and fails the build.
+ */
+#ifndef __BPF_TRACING__
+#warning "Compiler lacks ASM_GOTO support. Add -D __BPF_TRACING__ to your
compiler arguments"
+#endif
+
+#define static_cpu_has(bit) boot_cpu_has(bit)
+
+#else
+
/*
* Static testing of CPU features. Used the same as boot_cpu_has().
* These will statically patch the target code for additional
@@ -195,6 +209,7 @@ static __always_inline __pure bool _static_cpu_has(u16 bit)
boot_cpu_has(bit) : \
_static_cpu_has(bit) \
)
+#endif
#define cpu_has_bug(c, bit) cpu_has(c, (bit))
#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index b3e32b010ab1..c2c01f84df75 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -208,4 +208,22 @@ static inline int insn_offset_immediate(struct insn *insn)
return insn_offset_displacement(insn) + insn->displacement.nbytes;
}
+#define POP_SS_OPCODE 0x1f
+#define MOV_SREG_OPCODE 0x8e
+
+/*
+ * Intel SDM Vol.3A 6.8.3 states;
+ * "Any single-step trap that would be delivered following the MOV to SS
+ * instruction or POP to SS instruction (because EFLAGS.TF is 1) is
+ * suppressed."
+ * This function returns true if @insn is MOV SS or POP SS. On these
+ * instructions, single stepping is suppressed.
+ */
+static inline int insn_masking_exception(struct insn *insn)
+{
+ return insn->opcode.bytes[0] == POP_SS_OPCODE ||
+ (insn->opcode.bytes[0] == MOV_SREG_OPCODE &&
+ X86_MODRM_REG(insn->modrm.bytes[0]) == 2);
+}
+
#endif /* _ASM_X86_INSN_H */
diff --git a/arch/x86/include/asm/mmu_context.h
b/arch/x86/include/asm/mmu_context.h
index 57e3785d0d26..cf9911b5a53c 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -193,7 +193,7 @@ static inline int init_new_context(struct task_struct *tsk,
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
if (cpu_feature_enabled(X86_FEATURE_OSPKE)) {
- /* pkey 0 is the default and always allocated */
+ /* pkey 0 is the default and allocated implicitly */
mm->context.pkey_allocation_map = 0x1;
/* -1 means unallocated or invalid */
mm->context.execute_only_pkey = -1;
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
index a0ba1ffda0df..851c04b7a092 100644
--- a/arch/x86/include/asm/pkeys.h
+++ b/arch/x86/include/asm/pkeys.h
@@ -2,6 +2,8 @@
#ifndef _ASM_X86_PKEYS_H
#define _ASM_X86_PKEYS_H
+#define ARCH_DEFAULT_PKEY 0
+
#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1)
extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
@@ -15,7 +17,7 @@ extern int __execute_only_pkey(struct mm_struct *mm);
static inline int execute_only_pkey(struct mm_struct *mm)
{
if (!boot_cpu_has(X86_FEATURE_OSPKE))
- return 0;
+ return ARCH_DEFAULT_PKEY;
return __execute_only_pkey(mm);
}
@@ -49,13 +51,21 @@ bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
{
/*
* "Allocated" pkeys are those that have been returned
- * from pkey_alloc(). pkey 0 is special, and never
- * returned from pkey_alloc().
+ * from pkey_alloc() or pkey 0 which is allocated
+ * implicitly when the mm is created.
*/
- if (pkey <= 0)
+ if (pkey < 0)
return false;
if (pkey >= arch_max_pkey())
return false;
+ /*
+ * The exec-only pkey is set in the allocation map, but
+ * is not available to any of the user interfaces like
+ * mprotect_pkey().
+ */
+ if (pkey == mm->context.execute_only_pkey)
+ return false;
+
return mm_pkey_allocation_map(mm) & (1U << pkey);
}
diff --git a/arch/x86/kernel/apic/x2apic_cluster.c
b/arch/x86/kernel/apic/x2apic_cluster.c
index 8b04234e010b..7685444a106b 100644
--- a/arch/x86/kernel/apic/x2apic_cluster.c
+++ b/arch/x86/kernel/apic/x2apic_cluster.c
@@ -116,6 +116,7 @@ static void init_x2apic_ldr(void)
goto update;
}
cmsk = cluster_hotplug_mask;
+ cmsk->clusterid = cluster;
cluster_hotplug_mask = NULL;
update:
this_cpu_write(cluster_masks, cmsk);
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 0c408f8c4ed4..2d29e47c056e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -104,6 +104,12 @@ static bool __head check_la57_support(unsigned long
physaddr)
}
#endif
+/* Code in __startup_64() can be relocated during execution, but the compiler
+ * doesn't have to generate PC-relative relocations when accessing globals from
+ * that function. Clang actually does not generate them, which leads to
+ * boot-time crashes. To work around this problem, every global pointer must
+ * be adjusted using fixup_pointer().
+ */
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
{
@@ -113,6 +119,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
p4dval_t *p4d;
pudval_t *pud;
pmdval_t *pmd, pmd_entry;
+ pteval_t *mask_ptr;
bool la57;
int i;
unsigned int *next_pgt_ptr;
@@ -196,7 +203,8 @@ unsigned long __head __startup_64(unsigned long physaddr,
pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL;
/* Filter out unsupported __PAGE_KERNEL_* bits: */
- pmd_entry &= __supported_pte_mask;
+ mask_ptr = fixup_pointer(&__supported_pte_mask, physaddr);
+ pmd_entry &= *mask_ptr;
pmd_entry += sme_get_me_mask();
pmd_entry += physaddr;
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 0715f827607c..6f4d42377fe5 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -370,6 +370,10 @@ int __copy_instruction(u8 *dest, u8 *src, u8 *real, struct
insn *insn)
if (insn->opcode.bytes[0] == BREAKPOINT_INSTRUCTION)
return 0;
+ /* We should not singlestep on the exception masking instructions */
+ if (insn_masking_exception(insn))
+ return 0;
+
#ifdef CONFIG_X86_64
/* Only x86_64 has RIP relative instructions */
if (insn_rip_relative(insn)) {
diff --git a/arch/x86/kernel/machine_kexec_32.c
b/arch/x86/kernel/machine_kexec_32.c
index 60cdec6628b0..d1ab07ec8c9a 100644
--- a/arch/x86/kernel/machine_kexec_32.c
+++ b/arch/x86/kernel/machine_kexec_32.c
@@ -57,12 +57,17 @@ static void load_segments(void)
static void machine_kexec_free_page_tables(struct kimage *image)
{
free_page((unsigned long)image->arch.pgd);
+ image->arch.pgd = NULL;
#ifdef CONFIG_X86_PAE
free_page((unsigned long)image->arch.pmd0);
+ image->arch.pmd0 = NULL;
free_page((unsigned long)image->arch.pmd1);
+ image->arch.pmd1 = NULL;
#endif
free_page((unsigned long)image->arch.pte0);
+ image->arch.pte0 = NULL;
free_page((unsigned long)image->arch.pte1);
+ image->arch.pte1 = NULL;
}
static int machine_kexec_alloc_page_tables(struct kimage *image)
@@ -79,7 +84,6 @@ static int machine_kexec_alloc_page_tables(struct kimage
*image)
!image->arch.pmd0 || !image->arch.pmd1 ||
#endif
!image->arch.pte0 || !image->arch.pte1) {
- machine_kexec_free_page_tables(image);
return -ENOMEM;
}
return 0;
diff --git a/arch/x86/kernel/machine_kexec_64.c
b/arch/x86/kernel/machine_kexec_64.c
index a5e55d832d0a..6010449ca6d2 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -39,9 +39,13 @@ const struct kexec_file_ops * const kexec_file_loaders[] = {
static void free_transition_pgtable(struct kimage *image)
{
free_page((unsigned long)image->arch.p4d);
+ image->arch.p4d = NULL;
free_page((unsigned long)image->arch.pud);
+ image->arch.pud = NULL;
free_page((unsigned long)image->arch.pmd);
+ image->arch.pmd = NULL;
free_page((unsigned long)image->arch.pte);
+ image->arch.pte = NULL;
}
static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
@@ -91,7 +95,6 @@ static int init_transition_pgtable(struct kimage *image,
pgd_t *pgd)
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC_NOENC));
return 0;
err:
- free_transition_pgtable(image);
return result;
}
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 4b100fe0f508..12bb445fb98d 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -542,6 +542,7 @@ void set_personality_64bit(void)
clear_thread_flag(TIF_X32);
/* Pretend that this comes from a 64bit execve */
task_pt_regs(current)->orig_ax = __NR_execve;
+ current_thread_info()->status &= ~TS_COMPAT;
/* Ensure the corresponding mm is not marked. */
if (current->mm)
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c
index 85c7ef23d99f..c84bb5396958 100644
--- a/arch/x86/kernel/uprobes.c
+++ b/arch/x86/kernel/uprobes.c
@@ -299,6 +299,10 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe,
struct insn *insn, bool
if (is_prefix_bad(insn))
return -ENOTSUPP;
+ /* We should not singlestep on the exception masking instructions */
+ if (insn_masking_exception(insn))
+ return -ENOTSUPP;
+
if (x86_64)
good_insns = good_insns_64;
else
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index d7bc0eea20a5..6e98e0a7c923 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -94,26 +94,27 @@ int __arch_override_mprotect_pkey(struct vm_area_struct
*vma, int prot, int pkey
*/
if (pkey != -1)
return pkey;
- /*
- * Look for a protection-key-drive execute-only mapping
- * which is now being given permissions that are not
- * execute-only. Move it back to the default pkey.
- */
- if (vma_is_pkey_exec_only(vma) &&
- (prot & (PROT_READ|PROT_WRITE))) {
- return 0;
- }
+
/*
* The mapping is execute-only. Go try to get the
* execute-only protection key. If we fail to do that,
* fall through as if we do not have execute-only
- * support.
+ * support in this mm.
*/
if (prot == PROT_EXEC) {
pkey = execute_only_pkey(vma->vm_mm);
if (pkey > 0)
return pkey;
+ } else if (vma_is_pkey_exec_only(vma)) {
+ /*
+ * Protections are *not* PROT_EXEC, but the mapping
+ * is using the exec-only pkey. This mapping was
+ * PROT_EXEC and will no longer be. Move back to
+ * the default pkey.
+ */
+ return ARCH_DEFAULT_PKEY;
}
+
/*
* This is a vanilla, non-pkey mprotect (or we failed to
* setup execute-only), inherit the pkey from the VMA we
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 4d6a6edd4bf6..092947676143 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -255,7 +255,7 @@ $(obj)/tracex5_kern.o: $(obj)/syscall_nrs.h
$(obj)/%.o: $(src)/%.c
$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) -I$(obj) \
-I$(srctree)/tools/testing/selftests/bpf/ \
- -D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \
+ -D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value
-Wno-pointer-sign \
-D__TARGET_ARCH_$(ARCH) -Wno-compare-distinct-pointer-types \
-Wno-gnu-variable-sized-type-not-at-end \
-Wno-address-of-packed-member -Wno-tautological-compare \
diff --git a/tools/objtool/arch/x86/include/asm/insn.h
b/tools/objtool/arch/x86/include/asm/insn.h
index b3e32b010ab1..c2c01f84df75 100644
--- a/tools/objtool/arch/x86/include/asm/insn.h
+++ b/tools/objtool/arch/x86/include/asm/insn.h
@@ -208,4 +208,22 @@ static inline int insn_offset_immediate(struct insn *insn)
return insn_offset_displacement(insn) + insn->displacement.nbytes;
}
+#define POP_SS_OPCODE 0x1f
+#define MOV_SREG_OPCODE 0x8e
+
+/*
+ * Intel SDM Vol.3A 6.8.3 states;
+ * "Any single-step trap that would be delivered following the MOV to SS
+ * instruction or POP to SS instruction (because EFLAGS.TF is 1) is
+ * suppressed."
+ * This function returns true if @insn is MOV SS or POP SS. On these
+ * instructions, single stepping is suppressed.
+ */
+static inline int insn_masking_exception(struct insn *insn)
+{
+ return insn->opcode.bytes[0] == POP_SS_OPCODE ||
+ (insn->opcode.bytes[0] == MOV_SREG_OPCODE &&
+ X86_MODRM_REG(insn->modrm.bytes[0]) == 2);
+}
+
#endif /* _ASM_X86_INSN_H */
diff --git a/tools/testing/selftests/x86/Makefile
b/tools/testing/selftests/x86/Makefile
index d744991c0f4f..39f66bc29b82 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -11,7 +11,7 @@ CAN_BUILD_X86_64 := $(shell ./check_cc.sh $(CC)
trivial_64bit_program.c)
TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt
test_mremap_vdso \
check_initial_reg_state sigreturn iopl mpx-mini-test
ioperm \
- protection_keys test_vdso test_vsyscall
+ protection_keys test_vdso test_vsyscall mov_ss_trap
TARGETS_C_32BIT_ONLY := entry_from_vm86 syscall_arg_fault test_syscall_vdso
unwind_vdso \
test_FCMOV test_FCOMI test_FISTTP \
vdso_restorer
diff --git a/tools/testing/selftests/x86/mov_ss_trap.c
b/tools/testing/selftests/x86/mov_ss_trap.c
new file mode 100644
index 000000000000..3c3a022654f3
--- /dev/null
+++ b/tools/testing/selftests/x86/mov_ss_trap.c
@@ -0,0 +1,285 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mov_ss_trap.c: Exercise the bizarre side effects of a watchpoint on MOV SS
+ *
+ * This does MOV SS from a watchpointed address followed by various
+ * types of kernel entries. A MOV SS that hits a watchpoint will queue
+ * up a #DB trap but will not actually deliver that trap. The trap
+ * will be delivered after the next instruction instead. The CPU's logic
+ * seems to be:
+ *
+ * - Any fault: drop the pending #DB trap.
+ * - INT $N, INT3, INTO, SYSCALL, SYSENTER: enter the kernel and then
+ * deliver #DB.
+ * - ICEBP: enter the kernel but do not deliver the watchpoint trap
+ * - breakpoint: only one #DB is delivered (phew!)
+ *
+ * There are plenty of ways for a kernel to handle this incorrectly. This
+ * test tries to exercise all the cases.
+ *
+ * This should mostly cover CVE-2018-1087 and CVE-2018-8897.
+ */
+#define _GNU_SOURCE
+
+#include <stdlib.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/user.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+#include <setjmp.h>
+#include <sys/prctl.h>
+
+#define X86_EFLAGS_RF (1UL << 16)
+
+#if __x86_64__
+# define REG_IP REG_RIP
+#else
+# define REG_IP REG_EIP
+#endif
+
+unsigned short ss;
+extern unsigned char breakpoint_insn[];
+sigjmp_buf jmpbuf;
+static unsigned char altstack_data[SIGSTKSZ];
+
+static void enable_watchpoint(void)
+{
+ pid_t parent = getpid();
+ int status;
+
+ pid_t child = fork();
+ if (child < 0)
+ err(1, "fork");
+
+ if (child) {
+ if (waitpid(child, &status, 0) != child)
+ err(1, "waitpid for child");
+ } else {
+ unsigned long dr0, dr1, dr7;
+
+ dr0 = (unsigned long)&ss;
+ dr1 = (unsigned long)breakpoint_insn;
+ dr7 = ((1UL << 1) | /* G0 */
+ (3UL << 16) | /* RW0 = read or write */
+ (1UL << 18) | /* LEN0 = 2 bytes */
+ (1UL << 3)); /* G1, RW1 = insn */
+
+ if (ptrace(PTRACE_ATTACH, parent, NULL, NULL) != 0)
+ err(1, "PTRACE_ATTACH");
+
+ if (waitpid(parent, &status, 0) != parent)
+ err(1, "waitpid for child");
+
+ if (ptrace(PTRACE_POKEUSER, parent, (void *)offsetof(struct
user, u_debugreg[0]), dr0) != 0)
+ err(1, "PTRACE_POKEUSER DR0");
+
+ if (ptrace(PTRACE_POKEUSER, parent, (void *)offsetof(struct
user, u_debugreg[1]), dr1) != 0)
+ err(1, "PTRACE_POKEUSER DR1");
+
+ if (ptrace(PTRACE_POKEUSER, parent, (void *)offsetof(struct
user, u_debugreg[7]), dr7) != 0)
+ err(1, "PTRACE_POKEUSER DR7");
+
+ printf("\tDR0 = %lx, DR1 = %lx, DR7 = %lx\n", dr0, dr1, dr7);
+
+ if (ptrace(PTRACE_DETACH, parent, NULL, NULL) != 0)
+ err(1, "PTRACE_DETACH");
+
+ exit(0);
+ }
+}
+
+static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
+ int flags)
+{
+ struct sigaction sa;
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = handler;
+ sa.sa_flags = SA_SIGINFO | flags;
+ sigemptyset(&sa.sa_mask);
+ if (sigaction(sig, &sa, 0))
+ err(1, "sigaction");
+}
+
+static char const * const signames[] = {
+ [SIGSEGV] = "SIGSEGV",
+ [SIGBUS] = "SIBGUS",
+ [SIGTRAP] = "SIGTRAP",
+ [SIGILL] = "SIGILL",
+};
+
+static void sigtrap(int sig, siginfo_t *si, void *ctx_void)
+{
+ ucontext_t *ctx = ctx_void;
+
+ printf("\tGot SIGTRAP with RIP=%lx, EFLAGS.RF=%d\n",
+ (unsigned long)ctx->uc_mcontext.gregs[REG_IP],
+ !!(ctx->uc_mcontext.gregs[REG_EFL] & X86_EFLAGS_RF));
+}
+
+static void handle_and_return(int sig, siginfo_t *si, void *ctx_void)
+{
+ ucontext_t *ctx = ctx_void;
+
+ printf("\tGot %s with RIP=%lx\n", signames[sig],
+ (unsigned long)ctx->uc_mcontext.gregs[REG_IP]);
+}
+
+static void handle_and_longjmp(int sig, siginfo_t *si, void *ctx_void)
+{
+ ucontext_t *ctx = ctx_void;
+
+ printf("\tGot %s with RIP=%lx\n", signames[sig],
+ (unsigned long)ctx->uc_mcontext.gregs[REG_IP]);
+
+ siglongjmp(jmpbuf, 1);
+}
+
+int main()
+{
+ unsigned long nr;
+
+ asm volatile ("mov %%ss, %[ss]" : [ss] "=m" (ss));
+ printf("\tSS = 0x%hx, &SS = 0x%p\n", ss, &ss);
+
+ if (prctl(PR_SET_PTRACER, PR_SET_PTRACER_ANY, 0, 0, 0) == 0)
+ printf("\tPR_SET_PTRACER_ANY succeeded\n");
+
+ printf("\tSet up a watchpoint\n");
+ sethandler(SIGTRAP, sigtrap, 0);
+ enable_watchpoint();
+
+ printf("[RUN]\tRead from watched memory (should get SIGTRAP)\n");
+ asm volatile ("mov %[ss], %[tmp]" : [tmp] "=r" (nr) : [ss] "m" (ss));
+
+ printf("[RUN]\tMOV SS; INT3\n");
+ asm volatile ("mov %[ss], %%ss; int3" :: [ss] "m" (ss));
+
+ printf("[RUN]\tMOV SS; INT 3\n");
+ asm volatile ("mov %[ss], %%ss; .byte 0xcd, 0x3" :: [ss] "m" (ss));
+
+ printf("[RUN]\tMOV SS; CS CS INT3\n");
+ asm volatile ("mov %[ss], %%ss; .byte 0x2e, 0x2e; int3" :: [ss] "m"
(ss));
+
+ printf("[RUN]\tMOV SS; CSx14 INT3\n");
+ asm volatile ("mov %[ss], %%ss; .fill 14,1,0x2e; int3" :: [ss] "m"
(ss));
+
+ printf("[RUN]\tMOV SS; INT 4\n");
+ sethandler(SIGSEGV, handle_and_return, SA_RESETHAND);
+ asm volatile ("mov %[ss], %%ss; int $4" :: [ss] "m" (ss));
+
+#ifdef __i386__
+ printf("[RUN]\tMOV SS; INTO\n");
+ sethandler(SIGSEGV, handle_and_return, SA_RESETHAND);
+ nr = -1;
+ asm volatile ("add $1, %[tmp]; mov %[ss], %%ss; into"
+ : [tmp] "+r" (nr) : [ss] "m" (ss));
+#endif
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; ICEBP\n");
+
+ /* Some emulators (e.g. QEMU TCG) don't emulate ICEBP. */
+ sethandler(SIGILL, handle_and_longjmp, SA_RESETHAND);
+
+ asm volatile ("mov %[ss], %%ss; .byte 0xf1" :: [ss] "m" (ss));
+ }
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; CLI\n");
+ sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND);
+ asm volatile ("mov %[ss], %%ss; cli" :: [ss] "m" (ss));
+ }
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; #PF\n");
+ sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND);
+ asm volatile ("mov %[ss], %%ss; mov (-1), %[tmp]"
+ : [tmp] "=r" (nr) : [ss] "m" (ss));
+ }
+
+ /*
+ * INT $1: if #DB has DPL=3 and there isn't special handling,
+ * then the kernel will die.
+ */
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; INT 1\n");
+ sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND);
+ asm volatile ("mov %[ss], %%ss; int $1" :: [ss] "m" (ss));
+ }
+
+#ifdef __x86_64__
+ /*
+ * In principle, we should test 32-bit SYSCALL as well, but
+ * the calling convention is so unpredictable that it's
+ * not obviously worth the effort.
+ */
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; SYSCALL\n");
+ sethandler(SIGILL, handle_and_longjmp, SA_RESETHAND);
+ nr = SYS_getpid;
+ /*
+ * Toggle the high bit of RSP to make it noncanonical to
+ * strengthen this test on non-SMAP systems.
+ */
+ asm volatile ("btc $63, %%rsp\n\t"
+ "mov %[ss], %%ss; syscall\n\t"
+ "btc $63, %%rsp"
+ : "+a" (nr) : [ss] "m" (ss)
+ : "rcx"
+#ifdef __x86_64__
+ , "r11"
+#endif
+ );
+ }
+#endif
+
+ printf("[RUN]\tMOV SS; breakpointed NOP\n");
+ asm volatile ("mov %[ss], %%ss; breakpoint_insn: nop" :: [ss] "m" (ss));
+
+ /*
+ * Invoking SYSENTER directly breaks all the rules. Just handle
+ * the SIGSEGV.
+ */
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; SYSENTER\n");
+ stack_t stack = {
+ .ss_sp = altstack_data,
+ .ss_size = SIGSTKSZ,
+ };
+ if (sigaltstack(&stack, NULL) != 0)
+ err(1, "sigaltstack");
+ sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND |
SA_ONSTACK);
+ nr = SYS_getpid;
+ asm volatile ("mov %[ss], %%ss; SYSENTER" : "+a" (nr)
+ : [ss] "m" (ss) : "flags", "rcx"
+#ifdef __x86_64__
+ , "r11"
+#endif
+ );
+
+ /* We're unreachable here. SYSENTER forgets RIP. */
+ }
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ printf("[RUN]\tMOV SS; INT $0x80\n");
+ sethandler(SIGSEGV, handle_and_longjmp, SA_RESETHAND);
+ nr = 20; /* compat getpid */
+ asm volatile ("mov %[ss], %%ss; int $0x80"
+ : "+a" (nr) : [ss] "m" (ss)
+ : "flags"
+#ifdef __x86_64__
+ , "r8", "r9", "r10", "r11"
+#endif
+ );
+ }
+
+ printf("[OK]\tI aten't dead\n");
+ return 0;
+}
diff --git a/tools/testing/selftests/x86/mpx-mini-test.c
b/tools/testing/selftests/x86/mpx-mini-test.c
index 9c0325e1ea68..50f7e9272481 100644
--- a/tools/testing/selftests/x86/mpx-mini-test.c
+++ b/tools/testing/selftests/x86/mpx-mini-test.c
@@ -368,6 +368,11 @@ static int expected_bnd_index = -1;
uint64_t shadow_plb[NR_MPX_BOUNDS_REGISTERS][2]; /* shadow MPX bound registers
*/
unsigned long shadow_map[NR_MPX_BOUNDS_REGISTERS];
+/* Failed address bound checks: */
+#ifndef SEGV_BNDERR
+# define SEGV_BNDERR 3
+#endif
+
/*
* The kernel is supposed to provide some information about the bounds
* exception in the siginfo. It should match what we have in the bounds
@@ -419,8 +424,6 @@ void handler(int signum, siginfo_t *si, void *vucontext)
br_count++;
dprintf1("#BR 0x%jx (total seen: %d)\n", status, br_count);
-#define SEGV_BNDERR 3 /* failed address bound checks */
-
dprintf2("Saw a #BR! status 0x%jx at %016lx br_reason: %jx\n",
status, ip, br_reason);
dprintf2("si_signo: %d\n", si->si_signo);
diff --git a/tools/testing/selftests/x86/pkey-helpers.h
b/tools/testing/selftests/x86/pkey-helpers.h
index b3cb7670e026..254e5436bdd9 100644
--- a/tools/testing/selftests/x86/pkey-helpers.h
+++ b/tools/testing/selftests/x86/pkey-helpers.h
@@ -26,30 +26,26 @@ static inline void sigsafe_printf(const char *format, ...)
{
va_list ap;
- va_start(ap, format);
if (!dprint_in_signal) {
+ va_start(ap, format);
vprintf(format, ap);
+ va_end(ap);
} else {
int ret;
- int len = vsnprintf(dprint_in_signal_buffer,
- DPRINT_IN_SIGNAL_BUF_SIZE,
- format, ap);
/*
- * len is amount that would have been printed,
- * but actual write is truncated at BUF_SIZE.
+ * No printf() functions are signal-safe.
+ * They deadlock easily. Write the format
+ * string to get some output, even if
+ * incomplete.
*/
- if (len > DPRINT_IN_SIGNAL_BUF_SIZE)
- len = DPRINT_IN_SIGNAL_BUF_SIZE;
- ret = write(1, dprint_in_signal_buffer, len);
+ ret = write(1, format, strlen(format));
if (ret < 0)
- abort();
+ exit(1);
}
- va_end(ap);
}
#define dprintf_level(level, args...) do { \
if (level <= DEBUG_LEVEL) \
sigsafe_printf(args); \
- fflush(NULL); \
} while (0)
#define dprintf0(args...) dprintf_level(0, args)
#define dprintf1(args...) dprintf_level(1, args)
diff --git a/tools/testing/selftests/x86/protection_keys.c
b/tools/testing/selftests/x86/protection_keys.c
index f15aa5a76fe3..460b4bdf4c1e 100644
--- a/tools/testing/selftests/x86/protection_keys.c
+++ b/tools/testing/selftests/x86/protection_keys.c
@@ -72,10 +72,9 @@ extern void abort_hooks(void);
test_nr, iteration_nr); \
dprintf0("errno at assert: %d", errno); \
abort_hooks(); \
- assert(condition); \
+ exit(__LINE__); \
} \
} while (0)
-#define raw_assert(cond) assert(cond)
void cat_into_file(char *str, char *file)
{
@@ -87,12 +86,17 @@ void cat_into_file(char *str, char *file)
* these need to be raw because they are called under
* pkey_assert()
*/
- raw_assert(fd >= 0);
+ if (fd < 0) {
+ fprintf(stderr, "error opening '%s'\n", str);
+ perror("error: ");
+ exit(__LINE__);
+ }
+
ret = write(fd, str, strlen(str));
if (ret != strlen(str)) {
perror("write to file failed");
fprintf(stderr, "filename: '%s' str: '%s'\n", file, str);
- raw_assert(0);
+ exit(__LINE__);
}
close(fd);
}
@@ -191,26 +195,30 @@ void lots_o_noops_around_write(int *write_to_me)
#ifdef __i386__
#ifndef SYS_mprotect_key
-# define SYS_mprotect_key 380
+# define SYS_mprotect_key 380
#endif
+
#ifndef SYS_pkey_alloc
-# define SYS_pkey_alloc 381
-# define SYS_pkey_free 382
+# define SYS_pkey_alloc 381
+# define SYS_pkey_free 382
#endif
-#define REG_IP_IDX REG_EIP
-#define si_pkey_offset 0x14
+
+#define REG_IP_IDX REG_EIP
+#define si_pkey_offset 0x14
#else
#ifndef SYS_mprotect_key
-# define SYS_mprotect_key 329
+# define SYS_mprotect_key 329
#endif
+
#ifndef SYS_pkey_alloc
-# define SYS_pkey_alloc 330
-# define SYS_pkey_free 331
+# define SYS_pkey_alloc 330
+# define SYS_pkey_free 331
#endif
-#define REG_IP_IDX REG_RIP
-#define si_pkey_offset 0x20
+
+#define REG_IP_IDX REG_RIP
+#define si_pkey_offset 0x20
#endif
@@ -225,8 +233,14 @@ void dump_mem(void *dumpme, int len_bytes)
}
}
-#define SEGV_BNDERR 3 /* failed address bound checks */
-#define SEGV_PKUERR 4
+/* Failed address bound checks: */
+#ifndef SEGV_BNDERR
+# define SEGV_BNDERR 3
+#endif
+
+#ifndef SEGV_PKUERR
+# define SEGV_PKUERR 4
+#endif
static char *si_code_str(int si_code)
{
@@ -289,13 +303,6 @@ void signal_handler(int signum, siginfo_t *si, void
*vucontext)
dump_mem(pkru_ptr - 128, 256);
pkey_assert(*pkru_ptr);
- si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset);
- dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
- dump_mem(si_pkey_ptr - 8, 24);
- siginfo_pkey = *si_pkey_ptr;
- pkey_assert(siginfo_pkey < NR_PKEYS);
- last_si_pkey = siginfo_pkey;
-
if ((si->si_code == SEGV_MAPERR) ||
(si->si_code == SEGV_ACCERR) ||
(si->si_code == SEGV_BNDERR)) {
@@ -303,6 +310,13 @@ void signal_handler(int signum, siginfo_t *si, void
*vucontext)
exit(4);
}
+ si_pkey_ptr = (u32 *)(((u8 *)si) + si_pkey_offset);
+ dprintf1("si_pkey_ptr: %p\n", si_pkey_ptr);
+ dump_mem((u8 *)si_pkey_ptr - 8, 24);
+ siginfo_pkey = *si_pkey_ptr;
+ pkey_assert(siginfo_pkey < NR_PKEYS);
+ last_si_pkey = siginfo_pkey;
+
dprintf1("signal pkru from xsave: %08x\n", *pkru_ptr);
/* need __rdpkru() version so we do not do shadow_pkru checking */
dprintf1("signal pkru from pkru: %08x\n", __rdpkru());
@@ -311,22 +325,6 @@ void signal_handler(int signum, siginfo_t *si, void
*vucontext)
dprintf1("WARNING: set PRKU=0 to allow faulting instruction to
continue\n");
pkru_faults++;
dprintf1("<<<<==================================================\n");
- return;
- if (trapno == 14) {
- fprintf(stderr,
- "ERROR: In signal handler, page fault, trapno = %d, ip
= %016lx\n",
- trapno, ip);
- fprintf(stderr, "si_addr %p\n", si->si_addr);
- fprintf(stderr, "REG_ERR: %lx\n",
- (unsigned
long)uctxt->uc_mcontext.gregs[REG_ERR]);
- exit(1);
- } else {
- fprintf(stderr, "unexpected trap %d! at 0x%lx\n", trapno, ip);
- fprintf(stderr, "si_addr %p\n", si->si_addr);
- fprintf(stderr, "REG_ERR: %lx\n",
- (unsigned
long)uctxt->uc_mcontext.gregs[REG_ERR]);
- exit(2);
- }
dprint_in_signal = 0;
}
@@ -393,10 +391,15 @@ pid_t fork_lazy_child(void)
return forkret;
}
-#define PKEY_DISABLE_ACCESS 0x1
-#define PKEY_DISABLE_WRITE 0x2
+#ifndef PKEY_DISABLE_ACCESS
+# define PKEY_DISABLE_ACCESS 0x1
+#endif
+
+#ifndef PKEY_DISABLE_WRITE
+# define PKEY_DISABLE_WRITE 0x2
+#endif
-u32 pkey_get(int pkey, unsigned long flags)
+static u32 hw_pkey_get(int pkey, unsigned long flags)
{
u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
u32 pkru = __rdpkru();
@@ -418,7 +421,7 @@ u32 pkey_get(int pkey, unsigned long flags)
return masked_pkru;
}
-int pkey_set(int pkey, unsigned long rights, unsigned long flags)
+static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
{
u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
u32 old_pkru = __rdpkru();
@@ -452,15 +455,15 @@ void pkey_disable_set(int pkey, int flags)
pkey, flags);
pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
- pkey_rights = pkey_get(pkey, syscall_flags);
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
- dprintf1("%s(%d) pkey_get(%d): %x\n", __func__,
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
pkey, pkey, pkey_rights);
pkey_assert(pkey_rights >= 0);
pkey_rights |= flags;
- ret = pkey_set(pkey, pkey_rights, syscall_flags);
+ ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
assert(!ret);
/*pkru and flags have the same format */
shadow_pkru |= flags << (pkey * 2);
@@ -468,8 +471,8 @@ void pkey_disable_set(int pkey, int flags)
pkey_assert(ret >= 0);
- pkey_rights = pkey_get(pkey, syscall_flags);
- dprintf1("%s(%d) pkey_get(%d): %x\n", __func__,
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
pkey, pkey, pkey_rights);
dprintf1("%s(%d) pkru: 0x%x\n", __func__, pkey, rdpkru());
@@ -483,24 +486,24 @@ void pkey_disable_clear(int pkey, int flags)
{
unsigned long syscall_flags = 0;
int ret;
- int pkey_rights = pkey_get(pkey, syscall_flags);
+ int pkey_rights = hw_pkey_get(pkey, syscall_flags);
u32 orig_pkru = rdpkru();
pkey_assert(flags & (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE));
- dprintf1("%s(%d) pkey_get(%d): %x\n", __func__,
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
pkey, pkey, pkey_rights);
pkey_assert(pkey_rights >= 0);
pkey_rights |= flags;
- ret = pkey_set(pkey, pkey_rights, 0);
+ ret = hw_pkey_set(pkey, pkey_rights, 0);
/* pkru and flags have the same format */
shadow_pkru &= ~(flags << (pkey * 2));
pkey_assert(ret >= 0);
- pkey_rights = pkey_get(pkey, syscall_flags);
- dprintf1("%s(%d) pkey_get(%d): %x\n", __func__,
+ pkey_rights = hw_pkey_get(pkey, syscall_flags);
+ dprintf1("%s(%d) hw_pkey_get(%d): %x\n", __func__,
pkey, pkey, pkey_rights);
dprintf1("%s(%d) pkru: 0x%x\n", __func__, pkey, rdpkru());
@@ -674,10 +677,12 @@ int mprotect_pkey(void *ptr, size_t size, unsigned long
orig_prot,
struct pkey_malloc_record {
void *ptr;
long size;
+ int prot;
};
struct pkey_malloc_record *pkey_malloc_records;
+struct pkey_malloc_record *pkey_last_malloc_record;
long nr_pkey_malloc_records;
-void record_pkey_malloc(void *ptr, long size)
+void record_pkey_malloc(void *ptr, long size, int prot)
{
long i;
struct pkey_malloc_record *rec = NULL;
@@ -709,6 +714,8 @@ void record_pkey_malloc(void *ptr, long size)
(int)(rec - pkey_malloc_records), rec, ptr, size);
rec->ptr = ptr;
rec->size = size;
+ rec->prot = prot;
+ pkey_last_malloc_record = rec;
nr_pkey_malloc_records++;
}
@@ -753,7 +760,7 @@ void *malloc_pkey_with_mprotect(long size, int prot, u16
pkey)
pkey_assert(ptr != (void *)-1);
ret = mprotect_pkey((void *)ptr, PAGE_SIZE, prot, pkey);
pkey_assert(!ret);
- record_pkey_malloc(ptr, size);
+ record_pkey_malloc(ptr, size, prot);
rdpkru();
dprintf1("%s() for pkey %d @ %p\n", __func__, pkey, ptr);
@@ -774,7 +781,7 @@ void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
size = ALIGN_UP(size, HPAGE_SIZE * 2);
ptr = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
pkey_assert(ptr != (void *)-1);
- record_pkey_malloc(ptr, size);
+ record_pkey_malloc(ptr, size, prot);
mprotect_pkey(ptr, size, prot, pkey);
dprintf1("unaligned ptr: %p\n", ptr);
@@ -847,7 +854,7 @@ void *malloc_pkey_hugetlb(long size, int prot, u16 pkey)
pkey_assert(ptr != (void *)-1);
mprotect_pkey(ptr, size, prot, pkey);
- record_pkey_malloc(ptr, size);
+ record_pkey_malloc(ptr, size, prot);
dprintf1("mmap()'d hugetlbfs for pkey %d @ %p\n", pkey, ptr);
return ptr;
@@ -869,7 +876,7 @@ void *malloc_pkey_mmap_dax(long size, int prot, u16 pkey)
mprotect_pkey(ptr, size, prot, pkey);
- record_pkey_malloc(ptr, size);
+ record_pkey_malloc(ptr, size, prot);
dprintf1("mmap()'d for pkey %d @ %p\n", pkey, ptr);
close(fd);
@@ -918,13 +925,21 @@ void *malloc_pkey(long size, int prot, u16 pkey)
}
int last_pkru_faults;
+#define UNKNOWN_PKEY -2
void expected_pk_fault(int pkey)
{
dprintf2("%s(): last_pkru_faults: %d pkru_faults: %d\n",
__func__, last_pkru_faults, pkru_faults);
dprintf2("%s(%d): last_si_pkey: %d\n", __func__, pkey, last_si_pkey);
pkey_assert(last_pkru_faults + 1 == pkru_faults);
- pkey_assert(last_si_pkey == pkey);
+
+ /*
+ * For exec-only memory, we do not know the pkey in
+ * advance, so skip this check.
+ */
+ if (pkey != UNKNOWN_PKEY)
+ pkey_assert(last_si_pkey == pkey);
+
/*
* The signal handler shold have cleared out PKRU to let the
* test program continue. We now have to restore it.
@@ -939,10 +954,11 @@ void expected_pk_fault(int pkey)
last_si_pkey = -1;
}
-void do_not_expect_pk_fault(void)
-{
- pkey_assert(last_pkru_faults == pkru_faults);
-}
+#define do_not_expect_pk_fault(msg) do { \
+ if (last_pkru_faults != pkru_faults) \
+ dprintf0("unexpected PK fault: %s\n", msg); \
+ pkey_assert(last_pkru_faults == pkru_faults); \
+} while (0)
int test_fds[10] = { -1 };
int nr_test_fds;
@@ -1151,12 +1167,15 @@ void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
pkey_assert(i < NR_PKEYS*2);
/*
- * There are 16 pkeys supported in hardware. One is taken
- * up for the default (0) and another can be taken up by
- * an execute-only mapping. Ensure that we can allocate
- * at least 14 (16-2).
+ * There are 16 pkeys supported in hardware. Three are
+ * allocated by the time we get here:
+ * 1. The default key (0)
+ * 2. One possibly consumed by an execute-only mapping.
+ * 3. One allocated by the test code and passed in via
+ * 'pkey' to this function.
+ * Ensure that we can allocate at least another 13 (16-3).
*/
- pkey_assert(i >= NR_PKEYS-2);
+ pkey_assert(i >= NR_PKEYS-3);
for (i = 0; i < nr_allocated_pkeys; i++) {
err = sys_pkey_free(allocated_pkeys[i]);
@@ -1165,6 +1184,35 @@ void test_pkey_alloc_exhaust(int *ptr, u16 pkey)
}
}
+/*
+ * pkey 0 is special. It is allocated by default, so you do not
+ * have to call pkey_alloc() to use it first. Make sure that it
+ * is usable.
+ */
+void test_mprotect_with_pkey_0(int *ptr, u16 pkey)
+{
+ long size;
+ int prot;
+
+ assert(pkey_last_malloc_record);
+ size = pkey_last_malloc_record->size;
+ /*
+ * This is a bit of a hack. But mprotect() requires
+ * huge-page-aligned sizes when operating on hugetlbfs.
+ * So, make sure that we use something that's a multiple
+ * of a huge page when we can.
+ */
+ if (size >= HPAGE_SIZE)
+ size = HPAGE_SIZE;
+ prot = pkey_last_malloc_record->prot;
+
+ /* Use pkey 0 */
+ mprotect_pkey(ptr, size, prot, 0);
+
+ /* Make sure that we can set it back to the original pkey. */
+ mprotect_pkey(ptr, size, prot, pkey);
+}
+
void test_ptrace_of_child(int *ptr, u16 pkey)
{
__attribute__((__unused__)) int peek_result;
@@ -1228,7 +1276,7 @@ void test_ptrace_of_child(int *ptr, u16 pkey)
pkey_assert(ret != -1);
/* Now access from the current task, and expect NO exception: */
peek_result = read_ptr(plain_ptr);
- do_not_expect_pk_fault();
+ do_not_expect_pk_fault("read plain pointer after ptrace");
ret = ptrace(PTRACE_DETACH, child_pid, ignored, 0);
pkey_assert(ret != -1);
@@ -1241,12 +1289,9 @@ void test_ptrace_of_child(int *ptr, u16 pkey)
free(plain_ptr_unaligned);
}
-void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
+void *get_pointer_to_instructions(void)
{
void *p1;
- int scratch;
- int ptr_contents;
- int ret;
p1 = ALIGN_PTR_UP(&lots_o_noops_around_write, PAGE_SIZE);
dprintf3("&lots_o_noops: %p\n", &lots_o_noops_around_write);
@@ -1256,7 +1301,23 @@ void test_executing_on_unreadable_memory(int *ptr, u16
pkey)
/* Point 'p1' at the *second* page of the function: */
p1 += PAGE_SIZE;
+ /*
+ * Try to ensure we fault this in on next touch to ensure
+ * we get an instruction fault as opposed to a data one
+ */
madvise(p1, PAGE_SIZE, MADV_DONTNEED);
+
+ return p1;
+}
+
+void test_executing_on_unreadable_memory(int *ptr, u16 pkey)
+{
+ void *p1;
+ int scratch;
+ int ptr_contents;
+ int ret;
+
+ p1 = get_pointer_to_instructions();
lots_o_noops_around_write(&scratch);
ptr_contents = read_ptr(p1);
dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
@@ -1272,12 +1333,55 @@ void test_executing_on_unreadable_memory(int *ptr, u16
pkey)
*/
madvise(p1, PAGE_SIZE, MADV_DONTNEED);
lots_o_noops_around_write(&scratch);
- do_not_expect_pk_fault();
+ do_not_expect_pk_fault("executing on PROT_EXEC memory");
ptr_contents = read_ptr(p1);
dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
expected_pk_fault(pkey);
}
+void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
+{
+ void *p1;
+ int scratch;
+ int ptr_contents;
+ int ret;
+
+ dprintf1("%s() start\n", __func__);
+
+ p1 = get_pointer_to_instructions();
+ lots_o_noops_around_write(&scratch);
+ ptr_contents = read_ptr(p1);
+ dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
+
+ /* Use a *normal* mprotect(), not mprotect_pkey(): */
+ ret = mprotect(p1, PAGE_SIZE, PROT_EXEC);
+ pkey_assert(!ret);
+
+ dprintf2("pkru: %x\n", rdpkru());
+
+ /* Make sure this is an *instruction* fault */
+ madvise(p1, PAGE_SIZE, MADV_DONTNEED);
+ lots_o_noops_around_write(&scratch);
+ do_not_expect_pk_fault("executing on PROT_EXEC memory");
+ ptr_contents = read_ptr(p1);
+ dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
+ expected_pk_fault(UNKNOWN_PKEY);
+
+ /*
+ * Put the memory back to non-PROT_EXEC. Should clear the
+ * exec-only pkey off the VMA and allow it to be readable
+ * again. Go to PROT_NONE first to check for a kernel bug
+ * that did not clear the pkey when doing PROT_NONE.
+ */
+ ret = mprotect(p1, PAGE_SIZE, PROT_NONE);
+ pkey_assert(!ret);
+
+ ret = mprotect(p1, PAGE_SIZE, PROT_READ|PROT_EXEC);
+ pkey_assert(!ret);
+ ptr_contents = read_ptr(p1);
+ do_not_expect_pk_fault("plain read on recently PROT_EXEC area");
+}
+
void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey)
{
int size = PAGE_SIZE;
@@ -1302,6 +1406,8 @@ void (*pkey_tests[])(int *ptr, u16 pkey) = {
test_kernel_gup_of_access_disabled_region,
test_kernel_gup_write_to_write_disabled_region,
test_executing_on_unreadable_memory,
+ test_implicit_mprotect_exec_only_memory,
+ test_mprotect_with_pkey_0,
test_ptrace_of_child,
test_pkey_syscalls_on_non_allocated_pkey,
test_pkey_syscalls_bad_args,
