[Skiboot] [PATCH] opal-prd: handle devtmpfs mounted with noexec

[Georgy Yakovlev]

Closes: https://github.com/open-power/skiboot/issues/258
Signed-off-by: Georgy Yakovlev <gyakovlev at gentoo.org>
---
 external/opal-prd/opal-prd.c | 39 ++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/external/opal-prd/opal-prd.c b/external/opal-prd/opal-prd.c
index d74d8039..eb9a0b38 100644
--- a/external/opal-prd/opal-prd.c
+++ b/external/opal-prd/opal-prd.c
@@ -973,7 +973,10 @@ static int map_hbrt_file(struct opal_prd_ctx *ctx, const char *name)
 static int map_hbrt_physmem(struct opal_prd_ctx *ctx, const char *name)
 {
 	struct prd_range *range;
+	int rc;
 	void *buf;
+	void *ro_buf;
+	void *rwx_buf;
 
 	range = find_range(name, 0);
 	if (!range) {
@@ -981,15 +984,47 @@ static int map_hbrt_physmem(struct opal_prd_ctx *ctx, const char *name)
 		return -1;
 	}
 
-	buf = mmap(NULL, range->size, PROT_READ | PROT_WRITE | PROT_EXEC,
+	ro_buf = mmap(NULL, range->size, PROT_READ,
 			MAP_PRIVATE, ctx->fd, range->physaddr);
-	if (buf == MAP_FAILED) {
+	if (ro_buf == MAP_FAILED) {
 		pr_log(LOG_ERR, "IMAGE: mmap(range:%s, "
 				"phys:0x%016lx, size:0x%016lx) failed: %m",
 				name, range->physaddr, range->size);
 		return -1;
 	}
 
+	rwx_buf = mmap(NULL, range->size, PROT_WRITE,	
+			MAP_SHARED | MAP_ANONYMOUS, -1 , 0);
+	if (rwx_buf == MAP_FAILED) {
+		pr_log(LOG_ERR, "IMAGE: anon mmap(size:0x%016lx) failed: %m",
+				range->size);
+		return -1;
+	}
+
+	buf = memcpy(rwx_buf, ro_buf, range->size);
+	if (!buf) {
+		pr_log(LOG_ERR, "IMAGE: memcpy(dest:%p, "
+				"src: %p, size:0x%016lx) failed: %m",
+				rwx_buf, ro_buf, range->size);
+		return -1;
+	}
+
+	rc = munmap(ro_buf, range->size);
+	if (rc < 0) {
+		pr_log(LOG_ERR, "IMAGE: munmap("
+				"phys:0x%016lx, size:0x%016lx) failed: %m",
+				range->physaddr, range->size);
+		return -1;
+	}
+
+	rc = mprotect(buf, range->size, PROT_READ | PROT_WRITE | PROT_EXEC);
+	if (rc < 0) {
+		pr_log(LOG_ERR, "IMAGE: mprotect(phys:%p, "
+			"size:0x%016lx, rwx) failed: %m",
+			buf, range->size);
+		return -1;
+	}
+
 	ctx->code_addr = buf;
 	ctx->code_size = range->size;
 	return 0;
-- 
2.28.0