[PATCHv2 2/3] x86, ptdump: Simplify page flag evaluation code

From: Mathias Krause
Date: Sun Sep 21 2014 - 11:27:35 EST


The code evaluating the page flags is rather scattered. Simplify it by
folding the 'if .. else ..' part into the actual print call. Make use of
appropriate format strings to get the desired string width.

Also change the pt_dump_seq_printf() and pt_dump_cont_printf() macros to
use the common 'do ... while(0)' pattern instead of a compound statement
expression. We don't need no expression, just the statement.

Last, but not least, fix a few checkpatch warnings for the lines
touched.

Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
---
v2: - re-add pt_dump prefix to macros (and ignore checkpatch warnings) as
suggested by Ingo

arch/x86/mm/dump_pagetables.c | 107 ++++++++++++---------------------
1 file changed, 40 insertions(+), 67 deletions(-)

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 1a8053d1012e..0c3680332fcc 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -100,23 +100,23 @@ static struct addr_marker address_markers[] = {
#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)

-#define pt_dump_seq_printf(m, to_dmesg, fmt, args...) \
-({ \
- if (to_dmesg) \
- printk(KERN_INFO fmt, ##args); \
- else \
- if (m) \
- seq_printf(m, fmt, ##args); \
-})
-
-#define pt_dump_cont_printf(m, to_dmesg, fmt, args...) \
-({ \
- if (to_dmesg) \
- printk(KERN_CONT fmt, ##args); \
- else \
- if (m) \
- seq_printf(m, fmt, ##args); \
-})
+#define pt_dump_print(m, to_dmesg, fmt, args...) \
+ do { \
+ if (to_dmesg) \
+ pr_info(fmt, ##args); \
+ else \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+ } while (0)
+
+#define pt_dump_cont(m, to_dmesg, fmt, args...) \
+ do { \
+ if (to_dmesg) \
+ pr_cont(fmt, ##args); \
+ else \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+ } while (0)

/*
* Print a readable form of a pgprot_t to the seq_file
@@ -129,47 +129,23 @@ static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg)

if (!pgprot_val(prot)) {
/* Not present */
- pt_dump_cont_printf(m, dmsg, " ");
+ pt_dump_cont(m, dmsg, "%-26s", "");
} else {
- if (pr & _PAGE_USER)
- pt_dump_cont_printf(m, dmsg, "USR ");
- else
- pt_dump_cont_printf(m, dmsg, " ");
- if (pr & _PAGE_RW)
- pt_dump_cont_printf(m, dmsg, "RW ");
- else
- pt_dump_cont_printf(m, dmsg, "ro ");
- if (pr & _PAGE_PWT)
- pt_dump_cont_printf(m, dmsg, "PWT ");
- else
- pt_dump_cont_printf(m, dmsg, " ");
- if (pr & _PAGE_PCD)
- pt_dump_cont_printf(m, dmsg, "PCD ");
- else
- pt_dump_cont_printf(m, dmsg, " ");
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_USER ? "USR" : "");
+ pt_dump_cont(m, dmsg, "%-3s", pr & _PAGE_RW ? "RW" : "ro");
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_PWT ? "PWT" : "");
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_PCD ? "PCD" : "");

/* Bit 9 has a different meaning on level 3 vs 4 */
- if (level <= 3) {
- if (pr & _PAGE_PSE)
- pt_dump_cont_printf(m, dmsg, "PSE ");
- else
- pt_dump_cont_printf(m, dmsg, " ");
- } else {
- if (pr & _PAGE_PAT)
- pt_dump_cont_printf(m, dmsg, "pat ");
- else
- pt_dump_cont_printf(m, dmsg, " ");
- }
- if (pr & _PAGE_GLOBAL)
- pt_dump_cont_printf(m, dmsg, "GLB ");
+ if (level <= 3)
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_PSE ? "PSE" : "");
else
- pt_dump_cont_printf(m, dmsg, " ");
- if (pr & _PAGE_NX)
- pt_dump_cont_printf(m, dmsg, "NX ");
- else
- pt_dump_cont_printf(m, dmsg, "x ");
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_PAT ? "pat" : "");
+
+ pt_dump_cont(m, dmsg, "%-4s", pr & _PAGE_GLOBAL ? "GLB" : "");
+ pt_dump_cont(m, dmsg, "%-3s", pr & _PAGE_NX ? "NX" : "x");
}
- pt_dump_cont_printf(m, dmsg, "%s\n", level_name[level]);
+ pt_dump_cont(m, dmsg, "%s\n", level_name[level]);
}

/*
@@ -209,8 +185,8 @@ static void note_page(struct seq_file *m, struct pg_state *st,
st->level = level;
st->marker = address_markers;
st->lines = 0;
- pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
- st->marker->name);
+ pt_dump_print(m, st->to_dmesg, "---[ %s ]---\n",
+ st->marker->name);
} else if (prot != cur || level != st->level ||
st->current_address >= st->marker[1].start_address) {
const char *unit = units;
@@ -222,18 +198,16 @@ static void note_page(struct seq_file *m, struct pg_state *st,
*/
if (!st->marker->max_lines ||
st->lines < st->marker->max_lines) {
- pt_dump_seq_printf(m, st->to_dmesg,
- "0x%0*lx-0x%0*lx ",
- width, st->start_address,
- width, st->current_address);
+ pt_dump_print(m, st->to_dmesg, "0x%0*lx-0x%0*lx ",
+ width, st->start_address,
+ width, st->current_address);

delta = st->current_address - st->start_address;
while (!(delta & 1023) && unit[1]) {
delta >>= 10;
unit++;
}
- pt_dump_cont_printf(m, st->to_dmesg, "%9lu%c ",
- delta, *unit);
+ pt_dump_cont(m, st->to_dmesg, "%9lu%c ", delta, *unit);
printk_prot(m, st->current_prot, st->level,
st->to_dmesg);
}
@@ -249,15 +223,14 @@ static void note_page(struct seq_file *m, struct pg_state *st,
st->lines > st->marker->max_lines) {
unsigned long nskip =
st->lines - st->marker->max_lines;
- pt_dump_seq_printf(m, st->to_dmesg,
- "... %lu entr%s skipped ... \n",
- nskip,
- nskip == 1 ? "y" : "ies");
+ pt_dump_print(m, st->to_dmesg,
+ "... %lu entr%s skipped ...\n",
+ nskip, nskip == 1 ? "y" : "ies");
}
st->marker++;
st->lines = 0;
- pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
- st->marker->name);
+ pt_dump_print(m, st->to_dmesg, "---[ %s ]---\n",
+ st->marker->name);
}

st->start_address = st->current_address;
--
1.7.10.4

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