commit e3693eef06cadfc24d50abe34ae1bedf0385c3f8 Author: Jed Davis jld@mozilla.com Date: Fri Jan 27 14:25:50 2017 -0700

Bug 1286865 - Step 0: Turn off crash-on-seccomp-fail by default on non-nightly. r=gcp

MozReview-Commit-ID: 1It6HNizbAc

--HG-- extra : rebase_source : 1e96f11904abf2c38c5b4e50de7609ddc86cdd8a --- security/sandbox/linux/Sandbox.cpp | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/security/sandbox/linux/Sandbox.cpp b/security/sandbox/linux/Sandbox.cpp index 7f1182be9972..b4e65a1745df 100644 --- a/security/sandbox/linux/Sandbox.cpp +++ b/security/sandbox/linux/Sandbox.cpp @@ -73,6 +73,8 @@ int gSeccompTsyncBroadcastSignum = 0;

namespace mozilla {

+static bool gSandboxCrashOnError = false; + // This is initialized by SandboxSetCrashFunc(). SandboxCrashFunc gSandboxCrashFunc;

@@ -148,15 +150,18 @@ SigSysHandler(int nr, siginfo_t *info, void *void_context) // TODO, someday when this is enabled on MIPS: include the two extra // args in the error message. SANDBOX_LOG_ERROR("seccomp sandbox violation: pid %d, syscall %d," - " args %d %d %d %d %d %d. Killing process.", + " args %d %d %d %d %d %d.%s", pid, syscall_nr, - args[0], args[1], args[2], args[3], args[4], args[5]); + args[0], args[1], args[2], args[3], args[4], args[5], + gSandboxCrashOnError ? " Killing process." : "");

- // Bug 1017393: record syscall number somewhere useful. - info->si_addr = reinterpret_cast<void*>(syscall_nr); + if (gSandboxCrashOnError) { + // Bug 1017393: record syscall number somewhere useful. + info->si_addr = reinterpret_cast<void*>(syscall_nr);

- gSandboxCrashFunc(nr, info, &savedCtx); - _exit(127); + gSandboxCrashFunc(nr, info, &savedCtx); + _exit(127); + } }

/** @@ -515,6 +520,21 @@ SandboxEarlyInit(GeckoProcessType aType) } MOZ_RELEASE_ASSERT(IsSingleThreaded());

+ // Set gSandboxCrashOnError if appropriate. This doesn't need to + // happen this early, but for now it's here so that I don't need to + // add NSPR dependencies for PR_GetEnv. + // + // This also means that users with "unexpected threads" setups won't + // crash even on nightly. +#ifdef NIGHTLY_BUILD + gSandboxCrashOnError = true; +#endif + if (const char* envVar = getenv("MOZ_SANDBOX_CRASH_ON_ERROR")) { + if (envVar[0]) { + gSandboxCrashOnError = envVar[0] != '0'; + } + } + // Which kinds of resource isolation (of those that need to be set // up at this point) can be used by this process? bool canChroot = false;