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| author | Anders Roxell <anders.roxell@linaro.org> | 2022-02-24 17:22:15 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-03-01 13:51:09 +0100 |
| commit | 8219d31effa7be5dbc7ff915d7970672e028c701 (patch) | |
| tree | 480be91b21eaff3828e3a4285ab3bf714dc4a298 | |
| parent | powerpc: Fix build errors with newer binutils (diff) | |
| download | linux-8219d31effa7be5dbc7ff915d7970672e028c701.tar.xz linux-8219d31effa7be5dbc7ff915d7970672e028c701.zip | |
powerpc/lib/sstep: Fix build errors with newer binutils
Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
2.37.90.20220207) the following build error shows up:
{standard input}: Assembler messages:
{standard input}:10576: Error: unrecognized opcode: `stbcx.'
{standard input}:10680: Error: unrecognized opcode: `lharx'
{standard input}:10694: Error: unrecognized opcode: `lbarx'
Rework to add assembler directives [1] around the instruction. The
problem with this might be that we can trick a power6 into
single-stepping through an stbcx. for instance, and it will execute that
in kernel mode.
[1] https://sourceware.org/binutils/docs/as/PowerPC_002dPseudo.html#PowerPC_002dPseudo
Fixes: 350779a29f11 ("powerpc: Handle most loads and stores in instruction emulation code")
Cc: stable@vger.kernel.org # v4.14+
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220224162215.3406642-3-anders.roxell@linaro.org
| -rw-r--r-- | arch/powerpc/lib/sstep.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 31de2c5b586e..ef6ea8e156ed 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1089,7 +1089,10 @@ NOKPROBE_SYMBOL(emulate_dcbz); #define __put_user_asmx(x, addr, err, op, cr) \ __asm__ __volatile__( \ + ".machine push\n" \ + ".machine power8\n" \ "1: " op " %2,0,%3\n" \ + ".machine pop\n" \ " mfcr %1\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ @@ -1102,7 +1105,10 @@ NOKPROBE_SYMBOL(emulate_dcbz); #define __get_user_asmx(x, addr, err, op) \ __asm__ __volatile__( \ + ".machine push\n" \ + ".machine power8\n" \ "1: "op" %1,0,%2\n" \ + ".machine pop\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3: li %0,%3\n" \ |