From: Ian Jackson <ian.jackson@eu.citrix.com>
Date: Mon, 15 Oct 2018 14:22:53 +0000 (+0100)
Subject: libxencall: Improve linux syscall error messages
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~3085
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22man:///%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22man:/?a=commitdiff_plain;h=f355ed8448bc5685af749ebbd3b3816f3c8f927a;p=xen.git

libxencall: Improve linux syscall error messages

Make the bufdev and non-bufdev messages distinct, and always print the
non-constant argument (ie, the size).

This assists diagnosis.

CC: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Hans van Kranenburg <hans@knorrie.org>
Acked-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/tools/libs/call/linux.c b/tools/libs/call/linux.c
index d8a6306e04..51fa4899eb 100644
--- a/tools/libs/call/linux.c
+++ b/tools/libs/call/linux.c
@@ -93,7 +93,8 @@ static void *alloc_pages_bufdev(xencall_handle *xcall, size_t npages)
              xcall->buf_fd, 0);
     if ( p == MAP_FAILED )
     {
-        PERROR("alloc_pages: mmap failed");
+        PERROR("alloc_pages: mmap (,%zu*%lu,...) [bufdev] failed",
+               npages, (unsigned long)PAGE_SIZE);
         p = NULL;
     }
 
@@ -110,7 +111,7 @@ static void *alloc_pages_nobufdev(xencall_handle *xcall, size_t npages)
     p = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED, -1, 0);
     if ( p == MAP_FAILED )
     {
-        PERROR("alloc_pages: mmap failed");
+        PERROR("alloc_pages: mmap(,%zu,...) [nobufdev] failed", size);
         return NULL;
     }
 
@@ -119,7 +120,8 @@ static void *alloc_pages_nobufdev(xencall_handle *xcall, size_t npages)
     rc = madvise(p, npages * PAGE_SIZE, MADV_DONTFORK);
     if ( rc < 0 )
     {
-        PERROR("alloc_pages: madvise failed");
+        PERROR("alloc_pages: madvise (,%zu*%lu,) [nobufdev] failed",
+               npages, (unsigned long)PAGE_SIZE);
         goto out;
     }