File 0035-kexec-extend-the-semantics-of-kexec_iomem_... of Package kexec-tools

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File 0035-kexec-extend-the-semantics-of-kexec_iomem_for_each_l.patch of Package kexec-tools (Revision 8edb88b71952d1d032886b4536486cbd)

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From c95df0e099b14757de483245d7b1b45e2d6e2c91 Mon Sep 17 00:00:00 2001
From: AKASHI Takahiro <takahiro.akashi@linaro.org>
Date: Wed, 17 May 2017 14:51:41 +0900
Subject: [PATCH 35/45] kexec: extend the semantics of
 kexec_iomem_for_each_line

The current kexec_iomem_for_each_line() counts up all the lines for which
a callback function returns zero(0) or positive, and otherwise it stops
further scanning.
This behavior is inconvenient in some cases. For instance, on arm64, we want
to count up "System RAM" entries, but need to skip "reserved" entries.

So this patch extends the semantics so that we will continue to scan
succeeding entries but not count lines for which a callback function
returns positive.

The current users of kexec_iomem_for_each_line(), arm, sh and x86, will not
be affected by this change because
* arm
  The callback function only returns -1 or 0, and the return value of
  kexec_iomem_for_each_line() will never be used.
* sh, x86
  The callback function may return (-1 for sh,) 0 or 1, but always returns
  1 once we have reached the maximum number of entries allowed.
  Even so the current kexec_iomem_for_each_line() counts them up.
  This change actually fixes this bug.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
---
 kexec/kexec-iomem.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/kexec/kexec-iomem.c b/kexec/kexec-iomem.c
index 7ec385371a2c..b5b52b1c0803 100644
--- a/kexec/kexec-iomem.c
+++ b/kexec/kexec-iomem.c
@@ -18,6 +18,9 @@
  * Iterate over each line in the file returned by proc_iomem(). If match is
  * NULL or if the line matches with our match-pattern then call the
  * callback if non-NULL.
+ * If match is NULL, callback should return a negative if error.
+ * Otherwise the interation goes on, incrementing nr but only if callback
+ * returns 0 (matched).
  *
  * Return the number of lines matched.
  */
@@ -37,7 +40,7 @@ int kexec_iomem_for_each_line(char *match,
 	char *str;
 	int consumed;
 	int count;
-	int nr = 0;
+	int nr = 0, ret;
 
 	fp = fopen(iomem, "r");
 	if (!fp)
@@ -50,11 +53,13 @@ int kexec_iomem_for_each_line(char *match,
 		str = line + consumed;
 		size = end - start + 1;
 		if (!match || memcmp(str, match, strlen(match)) == 0) {
-			if (callback
-			    && callback(data, nr, str, start, size) < 0) {
-				break;
+			if (callback) {
+				ret = callback(data, nr, str, start, size);
+				if (ret < 0)
+					break;
+				else if (ret == 0)
+					nr++;
 			}
-			nr++;
 		}
 	}
 
-- 
2.13.0

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