You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
chromium/0005-sandbox-linux-seccomp-...

108 lines
2.9 KiB

From 1d44643a7c7cf650efd1093d22cd5bf859fdcb51 Mon Sep 17 00:00:00 2001
From: Shawn Anastasio <shawnanastasio@yahoo.com>
Date: Thu, 9 Aug 2018 20:52:13 -0500
Subject: [PATCH] sandbox/linux/seccomp-bpf: Add ppc64 syscall stub
---
sandbox/linux/seccomp-bpf/syscall.cc | 53 ++++++++++++++++++++++++++--
1 file changed, 51 insertions(+), 2 deletions(-)
Index: chromium-127.0.6533.72/sandbox/linux/seccomp-bpf/syscall.cc
===================================================================
--- chromium-127.0.6533.72.orig/sandbox/linux/seccomp-bpf/syscall.cc
+++ chromium-127.0.6533.72/sandbox/linux/seccomp-bpf/syscall.cc
@@ -18,7 +18,7 @@ namespace sandbox {
namespace {
#if defined(ARCH_CPU_X86_FAMILY) || defined(ARCH_CPU_ARM_FAMILY) || \
- defined(ARCH_CPU_MIPS_FAMILY)
+ defined(ARCH_CPU_MIPS_FAMILY) || defined (ARCH_CPU_PPC64_FAMILY)
// Number that's not currently used by any Linux kernel ABIs.
const int kInvalidSyscallNumber = 0x351d3;
#else
@@ -308,10 +308,54 @@ asm(// We need to be able to tell the ke
"2:ret\n"
".cfi_endproc\n"
".size SyscallAsm, .-SyscallAsm\n"
+#elif defined(__powerpc64__)
+ ".text\n"
+ ".align 4\n"
+ ".type SyscallAsm @function\n"
+ "SyscallAsm:\n"
+ ".cfi_startproc\n"
+
+ // Check if r3 is negative
+ "cmpdi 3, 0\n"
+ "bgt 2f\n"
+
+ // Load address of 3f into r3 and return
+ "mflr 10\n"
+ "bl 1f\n"
+ "1: mflr 3\n"
+ "mtlr 10\n"
+ "addi 3, 3, 4*13\n"
+ "blr\n"
+
+ // Load arguments from array into r3-8
+ // save param 3 in r10
+ "2:\n"
+ "mr 0, 3\n"
+ "ld 3, 0(4)\n"
+ "ld 5, 16(4)\n"
+ "ld 6, 24(4)\n"
+ "ld 7, 32(4)\n"
+ "ld 8, 40(4)\n"
+ "ld 4, 8(4)\n"
+ "li 9, 0\n"
+
+ // Enter kernel
+ "sc\n"
+
+ // Magic return address
+ "3:\n"
+ // Like MIPS, ppc64 return values are always positive.
+ // Check for error in cr0.SO and negate upon error
+ "bc 4, 3, 4f\n"
+ "neg 3, 3\n"
+ "4: blr\n"
+
+ ".cfi_endproc\n"
+ ".size SyscallAsm, .-SyscallAsm\n"
#endif
); // asm
-#if defined(__x86_64__)
+#if defined(__x86_64__) || defined(__powerpc64__)
extern "C" {
intptr_t SyscallAsm(intptr_t nr, const intptr_t args[6]);
}
@@ -425,6 +469,8 @@ intptr_t Syscall::Call(int nr,
ret = inout;
}
+#elif defined(__powerpc64__)
+ intptr_t ret = SyscallAsm(nr, args);
#else
#error "Unimplemented architecture"
#endif
@@ -441,8 +487,18 @@ void Syscall::PutValueInUcontext(intptr_
// needs to be changed back.
ret_val = -ret_val;
SECCOMP_PARM4(ctx) = 1;
- } else
+ } else {
SECCOMP_PARM4(ctx) = 0;
+ }
+#endif
+#if defined(__powerpc64__)
+ // Same as MIPS, need to invert ret and set error register (cr0.SO)
+ if (ret_val <= -1 && ret_val >= -4095) {
+ ret_val = -ret_val;
+ ctx->uc_mcontext.regs->ccr |= (1 << 28);
+ } else {
+ ctx->uc_mcontext.regs->ccr &= ~(1 << 28);
+ }
#endif
SECCOMP_RESULT(ctx) = static_cast<greg_t>(ret_val);
}