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powerpc/64s: Blacklist system_call() and system_call_common() from kprobes

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Convert some of the symbols into private symbols and blacklist
system_call_common() and system_call() from kprobes. We can't take a
trap at parts of these functions as either MSR_RI is unset or the
kernel stack pointer is not yet setup.

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
[mpe: Don't convert system_call_common to _GLOBAL()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Naveen N. Rao 2017-06-29 23:19:16 +05:30 committed by Michael Ellerman
parent 9d6c452352
commit cf7d6fb067
1 changed files with 14 additions and 12 deletions
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26
arch/powerpc/kernel/entry_64.S
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@ -57,7 +57,7 @@ system_call_common:
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION
extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
bne tabort_syscall
bne .Ltabort_syscall
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
andi. r10,r12,MSR_PR
@ -152,9 +152,9 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
CURRENT_THREAD_INFO(r11, r1)
ld r10,TI_FLAGS(r11)
andi. r11,r10,_TIF_SYSCALL_DOTRACE
bne syscall_dotrace /* does not return */
bne .Lsyscall_dotrace /* does not return */
cmpldi 0,r0,NR_syscalls
bge- syscall_enosys
bge- .Lsyscall_enosys
system_call: /* label this so stack traces look sane */
/*
@ -208,7 +208,7 @@ system_call: /* label this so stack traces look sane */
ld r9,TI_FLAGS(r12)
li r11,-MAX_ERRNO
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
bne- syscall_exit_work
bne- .Lsyscall_exit_work
/* If MSR_FP and MSR_VEC are set in user msr, then no need to restore */
li r7,MSR_FP
@ -217,12 +217,12 @@ system_call: /* label this so stack traces look sane */
#endif
and r0,r8,r7
cmpd r0,r7
bne syscall_restore_math
bne .Lsyscall_restore_math
.Lsyscall_restore_math_cont:
cmpld r3,r11
ld r5,_CCR(r1)
bge- syscall_error
bge- .Lsyscall_error
.Lsyscall_error_cont:
ld r7,_NIP(r1)
BEGIN_FTR_SECTION
@ -248,13 +248,13 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
RFI
b . /* prevent speculative execution */
syscall_error:
.Lsyscall_error:
oris r5,r5,0x1000 /* Set SO bit in CR */
neg r3,r3
std r5,_CCR(r1)
b .Lsyscall_error_cont
syscall_restore_math:
.Lsyscall_restore_math:
/*
* Some initial tests from restore_math to avoid the heavyweight
* C code entry and MSR manipulations.
@ -289,7 +289,7 @@ syscall_restore_math:
b .Lsyscall_restore_math_cont
/* Traced system call support */
syscall_dotrace:
.Lsyscall_dotrace:
bl save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl do_syscall_trace_enter
@ -322,11 +322,11 @@ syscall_dotrace:
b .Lsyscall_exit
syscall_enosys:
.Lsyscall_enosys:
li r3,-ENOSYS
b .Lsyscall_exit
syscall_exit_work:
.Lsyscall_exit_work:
#ifdef CONFIG_PPC_BOOK3S
li r10,MSR_RI
mtmsrd r10,1 /* Restore RI */
@ -386,7 +386,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
b ret_from_except
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
tabort_syscall:
.Ltabort_syscall:
/* Firstly we need to enable TM in the kernel */
mfmsr r10
li r9, 1
@ -412,6 +412,8 @@ tabort_syscall:
rfid
b . /* prevent speculative execution */
#endif
_ASM_NOKPROBE_SYMBOL(system_call_common);
_ASM_NOKPROBE_SYMBOL(system_call);
/* Save non-volatile GPRs, if not already saved. */
_GLOBAL(save_nvgprs)