From dd9959ab0eef30dfbed4f39fbf7c38924e1862c6 Mon Sep 17 00:00:00 2001 From: Peter Ammon Date: Thu, 21 Mar 2019 14:18:28 -0700 Subject: [PATCH] JSBigString to map via MAP_PRIVATE not MAP_SHARED Summary: JSBigString was inadvertently changed to a shared mapping. This means that any changes to the string will be written back to the file. Ensure we have a private (COW) mapping. Reviewed By: kodafb Differential Revision: D14532757 fbshipit-source-id: 6afb9635493496c90904f1432847c2f0da882c58 --- ReactCommon/cxxreact/JSBigString.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ReactCommon/cxxreact/JSBigString.cpp b/ReactCommon/cxxreact/JSBigString.cpp index 0a0571466..fb6540d14 100644 --- a/ReactCommon/cxxreact/JSBigString.cpp +++ b/ReactCommon/cxxreact/JSBigString.cpp @@ -52,7 +52,7 @@ JSBigFileString::~JSBigFileString() { const char *JSBigFileString::c_str() const { if (!m_data) { m_data = - (const char *) mmap(0, m_size, PROT_READ, MAP_SHARED, m_fd, m_mapOff); + (const char *) mmap(0, m_size, PROT_READ, MAP_PRIVATE, m_fd, m_mapOff); CHECK(m_data != MAP_FAILED) << " fd: " << m_fd << " size: " << m_size