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dtrace: fix userspace access on boxes with SMAP

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dtrace has its own routines which were not updated after SMAP support got
implemented. Use ifunc just like for other routines.

This in particular fixes ustack().

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18542
This commit is contained in:
Mateusz Guzik 2018-12-13 20:09:38 +00:00
parent 87b3975e36
commit 8ca79fbd4a
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=342053
2 changed files with 161 additions and 14 deletions
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107
sys/cddl/dev/dtrace/amd64/dtrace_asm.S
View File

@ -208,7 +208,7 @@ dtrace_caller(int aframes)
void
dtrace_copy(uintptr_t src, uintptr_t dest, size_t size)
*/
ENTRY(dtrace_copy)
ENTRY(dtrace_copy_nosmap)
pushq %rbp
movq %rsp, %rbp
@ -218,14 +218,28 @@ dtrace_copy(uintptr_t src, uintptr_t dest, size_t size)
smovb /* move from %ds:rsi to %ed:rdi */
leave
ret
END(dtrace_copy)
END(dtrace_copy_nosmap)
ENTRY(dtrace_copy_smap)
pushq %rbp
movq %rsp, %rbp
xchgq %rdi, %rsi /* make %rsi source, %rdi dest */
movq %rdx, %rcx /* load count */
stac
repz /* repeat for count ... */
smovb /* move from %ds:rsi to %ed:rdi */
clac
leave
ret
END(dtrace_copy_smap)
/*
void
dtrace_copystr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
volatile uint16_t *flags)
*/
ENTRY(dtrace_copystr)
ENTRY(dtrace_copystr_nosmap)
pushq %rbp
movq %rsp, %rbp
@ -248,55 +262,120 @@ dtrace_copystr(uintptr_t uaddr, uintptr_t kaddr, size_t size,
leave
ret
END(dtrace_copystr)
END(dtrace_copystr_nosmap)
ENTRY(dtrace_copystr_smap)
pushq %rbp
movq %rsp, %rbp
stac
0:
movb (%rdi), %al /* load from source */
movb %al, (%rsi) /* store to destination */
addq $1, %rdi /* increment source pointer */
addq $1, %rsi /* increment destination pointer */
subq $1, %rdx /* decrement remaining count */
cmpb $0, %al
je 2f
testq $0xfff, %rdx /* test if count is 4k-aligned */
jnz 1f /* if not, continue with copying */
testq $CPU_DTRACE_BADADDR, (%rcx) /* load and test dtrace flags */
jnz 2f
1:
cmpq $0, %rdx
jne 0b
2:
clac
leave
ret
END(dtrace_copystr_smap)
/*
uintptr_t
dtrace_fulword(void *addr)
*/
ENTRY(dtrace_fulword)
ENTRY(dtrace_fulword_nosmap)
movq (%rdi), %rax
ret
END(dtrace_fulword)
END(dtrace_fulword_nosmap)
ENTRY(dtrace_fulword_smap)
stac
movq (%rdi), %rax
clac
ret
END(dtrace_fulword_smap)
/*
uint8_t
dtrace_fuword8_nocheck(void *addr)
*/
ENTRY(dtrace_fuword8_nocheck)
ENTRY(dtrace_fuword8_nocheck_nosmap)
xorq %rax, %rax
movb (%rdi), %al
ret
END(dtrace_fuword8_nocheck)
END(dtrace_fuword8_nocheck_nosmap)
ENTRY(dtrace_fuword8_nocheck_smap)
stac
xorq %rax, %rax
movb (%rdi), %al
clac
ret
END(dtrace_fuword8_nocheck_smap)
/*
uint16_t
dtrace_fuword16_nocheck(void *addr)
*/
ENTRY(dtrace_fuword16_nocheck)
ENTRY(dtrace_fuword16_nocheck_nosmap)
xorq %rax, %rax
movw (%rdi), %ax
ret
END(dtrace_fuword16_nocheck)
END(dtrace_fuword16_nocheck_nosmap)
ENTRY(dtrace_fuword16_nocheck_smap)
stac
xorq %rax, %rax
movw (%rdi), %ax
clac
ret
END(dtrace_fuword16_nocheck_smap)
/*
uint32_t
dtrace_fuword32_nocheck(void *addr)
*/
ENTRY(dtrace_fuword32_nocheck)
ENTRY(dtrace_fuword32_nocheck_nosmap)
xorq %rax, %rax
movl (%rdi), %eax
ret
END(dtrace_fuword32_nocheck)
END(dtrace_fuword32_nocheck_nosmap)
ENTRY(dtrace_fuword32_nocheck_smap)
stac
xorq %rax, %rax
movl (%rdi), %eax
clac
ret
END(dtrace_fuword32_nocheck_smap)
/*
uint64_t
dtrace_fuword64_nocheck(void *addr)
*/
ENTRY(dtrace_fuword64_nocheck)
ENTRY(dtrace_fuword64_nocheck_nosmap)
movq (%rdi), %rax
ret
END(dtrace_fuword64_nocheck)
END(dtrace_fuword64_nocheck_nosmap)
ENTRY(dtrace_fuword64_nocheck_smap)
stac
movq (%rdi), %rax
clac
ret
END(dtrace_fuword64_nocheck_smap)
/*
void

68
sys/cddl/dev/dtrace/amd64/dtrace_isa.c
View File

@ -37,6 +37,7 @@
#include <machine/md_var.h>
#include <machine/reg.h>
#include <machine/stack.h>
#include <x86/ifunc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
@ -664,3 +665,70 @@ dtrace_fuword64(void *uaddr)
}
return (dtrace_fuword64_nocheck(uaddr));
}
/*
* ifunc resolvers for SMAP support
*/
void dtrace_copy_nosmap(uintptr_t, uintptr_t, size_t);
void dtrace_copy_smap(uintptr_t, uintptr_t, size_t);
DEFINE_IFUNC(, void, dtrace_copy, (uintptr_t, uintptr_t, size_t), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_copy_smap : dtrace_copy_nosmap);
}
void dtrace_copystr_nosmap(uintptr_t, uintptr_t, size_t, volatile uint16_t *);
void dtrace_copystr_smap(uintptr_t, uintptr_t, size_t, volatile uint16_t *);
DEFINE_IFUNC(, void, dtrace_copystr, (uintptr_t, uintptr_t, size_t,
volatile uint16_t *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_copystr_smap : dtrace_copystr_nosmap);
}
uintptr_t dtrace_fulword_nosmap(void *);
uintptr_t dtrace_fulword_smap(void *);
DEFINE_IFUNC(, uintptr_t, dtrace_fulword, (void *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_fulword_smap : dtrace_fulword_nosmap);
}
uint8_t dtrace_fuword8_nocheck_nosmap(void *);
uint8_t dtrace_fuword8_nocheck_smap(void *);
DEFINE_IFUNC(, uint8_t, dtrace_fuword8_nocheck, (void *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_fuword8_nocheck_smap : dtrace_fuword8_nocheck_nosmap);
}
uint16_t dtrace_fuword16_nocheck_nosmap(void *);
uint16_t dtrace_fuword16_nocheck_smap(void *);
DEFINE_IFUNC(, uint16_t, dtrace_fuword16_nocheck, (void *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_fuword16_nocheck_smap : dtrace_fuword16_nocheck_nosmap);
}
uint32_t dtrace_fuword32_nocheck_nosmap(void *);
uint32_t dtrace_fuword32_nocheck_smap(void *);
DEFINE_IFUNC(, uint32_t, dtrace_fuword32_nocheck, (void *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_fuword32_nocheck_smap : dtrace_fuword32_nocheck_nosmap);
}
uint64_t dtrace_fuword64_nocheck_nosmap(void *);
uint64_t dtrace_fuword64_nocheck_smap(void *);
DEFINE_IFUNC(, uint64_t, dtrace_fuword64_nocheck, (void *), static)
{
return ((cpu_stdext_feature & CPUID_STDEXT_SMAP) != 0 ?
dtrace_fuword64_nocheck_smap : dtrace_fuword64_nocheck_nosmap);
}