Commit d2e4e89a authored by Mike Frysinger's avatar Mike Frysinger Committed by Sasha Levin

sparc: Fix system call tracing register handling.

[ Upstream commit 1a40b953 ]

A system call trace trigger on entry allows the tracing
process to inspect and potentially change the traced
process's registers.

Account for that by reloading the %g1 (syscall number)
and %i0-%i5 (syscall argument) values.  We need to be
careful to revalidate the range of %g1, and reload the
system call table entry it corresponds to into %l7.
Reported-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Tested-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
parent daaaff27
......@@ -948,7 +948,24 @@ linux_syscall_trace:
cmp %o0, 0
bne 3f
mov -ENOSYS, %o0
/* Syscall tracing can modify the registers. */
ld [%sp + STACKFRAME_SZ + PT_G1], %g1
sethi %hi(sys_call_table), %l7
ld [%sp + STACKFRAME_SZ + PT_I0], %i0
or %l7, %lo(sys_call_table), %l7
ld [%sp + STACKFRAME_SZ + PT_I1], %i1
ld [%sp + STACKFRAME_SZ + PT_I2], %i2
ld [%sp + STACKFRAME_SZ + PT_I3], %i3
ld [%sp + STACKFRAME_SZ + PT_I4], %i4
ld [%sp + STACKFRAME_SZ + PT_I5], %i5
cmp %g1, NR_syscalls
bgeu 3f
mov -ENOSYS, %o0
sll %g1, 2, %l4
mov %i0, %o0
ld [%l7 + %l4], %l7
mov %i1, %o1
mov %i2, %o2
mov %i3, %o3
......
......@@ -158,7 +158,25 @@ linux_syscall_trace32:
add %sp, PTREGS_OFF, %o0
brnz,pn %o0, 3f
mov -ENOSYS, %o0
/* Syscall tracing can modify the registers. */
ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1
sethi %hi(sys_call_table32), %l7
ldx [%sp + PTREGS_OFF + PT_V9_I0], %i0
or %l7, %lo(sys_call_table32), %l7
ldx [%sp + PTREGS_OFF + PT_V9_I1], %i1
ldx [%sp + PTREGS_OFF + PT_V9_I2], %i2
ldx [%sp + PTREGS_OFF + PT_V9_I3], %i3
ldx [%sp + PTREGS_OFF + PT_V9_I4], %i4
ldx [%sp + PTREGS_OFF + PT_V9_I5], %i5
cmp %g1, NR_syscalls
bgeu,pn %xcc, 3f
mov -ENOSYS, %o0
sll %g1, 2, %l4
srl %i0, 0, %o0
lduw [%l7 + %l4], %l7
srl %i4, 0, %o4
srl %i1, 0, %o1
srl %i2, 0, %o2
......@@ -170,7 +188,25 @@ linux_syscall_trace:
add %sp, PTREGS_OFF, %o0
brnz,pn %o0, 3f
mov -ENOSYS, %o0
/* Syscall tracing can modify the registers. */
ldx [%sp + PTREGS_OFF + PT_V9_G1], %g1
sethi %hi(sys_call_table64), %l7
ldx [%sp + PTREGS_OFF + PT_V9_I0], %i0
or %l7, %lo(sys_call_table64), %l7
ldx [%sp + PTREGS_OFF + PT_V9_I1], %i1
ldx [%sp + PTREGS_OFF + PT_V9_I2], %i2
ldx [%sp + PTREGS_OFF + PT_V9_I3], %i3
ldx [%sp + PTREGS_OFF + PT_V9_I4], %i4
ldx [%sp + PTREGS_OFF + PT_V9_I5], %i5
cmp %g1, NR_syscalls
bgeu,pn %xcc, 3f
mov -ENOSYS, %o0
sll %g1, 2, %l4
mov %i0, %o0
lduw [%l7 + %l4], %l7
mov %i1, %o1
mov %i2, %o2
mov %i3, %o3
......
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