From: Chip Davis Subject: [PATCH] ntdll: Try mmap again without exec if it fails with it. Message-Id: <20190924004449.16473-1-cdavis@codeweavers.com> Date: Mon, 23 Sep 2019 19:44:49 -0500 On some systems, mmap(2) with PROT_WRITE | PROT_EXEC can legitimately fail. If we added PROT_EXEC implicitly, try again without it. Signed-off-by: Chip Davis --- dlls/ntdll/virtual.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/dlls/ntdll/virtual.c b/dlls/ntdll/virtual.c index 8b94f2eb67b0..cd9e8a93ee16 100644 --- a/dlls/ntdll/virtual.c +++ b/dlls/ntdll/virtual.c @@ -1203,6 +1203,7 @@ static NTSTATUS map_file_into_view( struct file_view *view, int fd, size_t start /* only try mmap if media is not removable (or if we require write access) */ if (!removable || (flags & MAP_SHARED)) { +try_again: if (mmap( (char *)view->base + start, size, prot, flags, fd, offset ) != (void *)-1) goto done; @@ -1223,7 +1224,16 @@ static NTSTATUS map_file_into_view( struct file_view *view, int fd, size_t start case EPERM: /* noexec filesystem, fall back to read() */ if (flags & MAP_SHARED) { - if (prot & PROT_EXEC) ERR( "failed to set PROT_EXEC on file map, noexec filesystem?\n" ); + if (prot & PROT_EXEC) + { + if (force_exec_prot && (vprot & (VPROT_WRITE|VPROT_EXEC)) == VPROT_WRITE) + { + /* exec + write may legitimately fail, in that case fall back to write only */ + prot &= ~PROT_EXEC; + goto try_again; + } + ERR( "failed to set PROT_EXEC on file map, noexec filesystem?\n" ); + } return STATUS_ACCESS_DENIED; } if (prot & PROT_EXEC) WARN( "failed to set PROT_EXEC on file map, noexec filesystem?\n" ); -- 2.21.0