]> git.ipfire.org Git - thirdparty/kernel/stable.git/commitdiff
minmax: add a few more MIN_T/MAX_T users
authorLinus Torvalds <torvalds@linux-foundation.org>
Sun, 28 Jul 2024 20:03:48 +0000 (13:03 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 2 Oct 2025 11:40:43 +0000 (13:40 +0200)
commit 4477b39c32fdc03363affef4b11d48391e6dc9ff upstream.

Commit 3a7e02c040b1 ("minmax: avoid overly complicated constant
expressions in VM code") added the simpler MIN_T/MAX_T macros in order
to avoid some excessive expansion from the rather complicated regular
min/max macros.

The complexity of those macros stems from two issues:

 (a) trying to use them in situations that require a C constant
     expression (in static initializers and for array sizes)

 (b) the type sanity checking

and MIN_T/MAX_T avoids both of these issues.

Now, in the whole (long) discussion about all this, it was pointed out
that the whole type sanity checking is entirely unnecessary for
min_t/max_t which get a fixed type that the comparison is done in.

But that still leaves min_t/max_t unnecessarily complicated due to
worries about the C constant expression case.

However, it turns out that there really aren't very many cases that use
min_t/max_t for this, and we can just force-convert those.

This does exactly that.

Which in turn will then allow for much simpler implementations of
min_t()/max_t().  All the usual "macros in all upper case will evaluate
the arguments multiple times" rules apply.

We should do all the same things for the regular min/max() vs MIN/MAX()
cases, but that has the added complexity of various drivers defining
their own local versions of MIN/MAX, so that needs another level of
fixes first.

Link: https://lore.kernel.org/all/b47fad1d0cf8449886ad148f8c013dae@AcuMS.aculab.com/
Cc: David Laight <David.Laight@aculab.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eliav Farber <farbere@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/mm/pgtable.c
drivers/edac/sb_edac.c
drivers/gpu/drm/drm_color_mgmt.c
drivers/md/dm-integrity.c
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
net/ipv4/proc.c
net/ipv6/proc.c

index 77ee0012f84971cd43abb18b4c5dd51be37bb5c7..a84d3d82824a78cc4866b236d263ab814485d5b3 100644 (file)
@@ -107,7 +107,7 @@ static inline void pgd_list_del(pgd_t *pgd)
 #define UNSHARED_PTRS_PER_PGD                          \
        (SHARED_KERNEL_PMD ? KERNEL_PGD_BOUNDARY : PTRS_PER_PGD)
 #define MAX_UNSHARED_PTRS_PER_PGD                      \
-       max_t(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD)
+       MAX_T(size_t, KERNEL_PGD_BOUNDARY, PTRS_PER_PGD)
 
 
 static void pgd_set_mm(pgd_t *pgd, struct mm_struct *mm)
index 8e39370fdb5cd6a84469e8032a50442676ef103c..f0de7b18a53fd0b3a29d9b8a04bdb2d178812f39 100644 (file)
@@ -109,8 +109,8 @@ static const u32 knl_interleave_list[] = {
        0x104, 0x10c, 0x114, 0x11c,   /* 20-23 */
 };
 #define MAX_INTERLEAVE                                                 \
-       (max_t(unsigned int, ARRAY_SIZE(sbridge_interleave_list),       \
-              max_t(unsigned int, ARRAY_SIZE(ibridge_interleave_list), \
+       (MAX_T(unsigned int, ARRAY_SIZE(sbridge_interleave_list),       \
+              MAX_T(unsigned int, ARRAY_SIZE(ibridge_interleave_list), \
                     ARRAY_SIZE(knl_interleave_list))))
 
 struct interleave_pkg {
index d021497841b84665b08db26088ec67eab9c5f45e..3969dc548cff605cbdd3d56dceafb2ca00a5c886 100644 (file)
@@ -532,7 +532,7 @@ int drm_plane_create_color_properties(struct drm_plane *plane,
 {
        struct drm_device *dev = plane->dev;
        struct drm_property *prop;
-       struct drm_prop_enum_list enum_list[max_t(int, DRM_COLOR_ENCODING_MAX,
+       struct drm_prop_enum_list enum_list[MAX_T(int, DRM_COLOR_ENCODING_MAX,
                                                       DRM_COLOR_RANGE_MAX)];
        int i, len;
 
index efd0732a8c107b444b5c7baa581f564f512996c4..a201019babe40b8f48bdb2121441b8a1932afba2 100644 (file)
@@ -2618,7 +2618,7 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned int write_start
                                    unlikely(from_replay) &&
 #endif
                                    ic->internal_hash) {
-                                       char test_tag[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
+                                       char test_tag[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
 
                                        integrity_sector_checksum(ic, sec + ((l - j) << ic->sb->log2_sectors_per_block),
                                                                  (char *)access_journal_data(ic, i, l), test_tag);
index 948e35c405a844bb982a6cdd544b7b1d59ed2610..be84aed471603cf044a275a5bff7dd69715193ba 100644 (file)
@@ -2827,7 +2827,7 @@ static void stmmac_dma_interrupt(struct stmmac_priv *priv)
        u32 channels_to_check = tx_channel_count > rx_channel_count ?
                                tx_channel_count : rx_channel_count;
        u32 chan;
-       int status[max_t(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
+       int status[MAX_T(u32, MTL_MAX_TX_QUEUES, MTL_MAX_RX_QUEUES)];
 
        /* Make sure we never check beyond our status buffer. */
        if (WARN_ON_ONCE(channels_to_check > ARRAY_SIZE(status)))
index 1f52c5f2d3475f9ed1be1001c6e83b40d734b259..234b2e56be4f2a50d9613af0cdbaf20714dcbe9c 100644 (file)
@@ -43,7 +43,7 @@
 #include <net/sock.h>
 #include <net/raw.h>
 
-#define TCPUDP_MIB_MAX max_t(u32, UDP_MIB_MAX, TCP_MIB_MAX)
+#define TCPUDP_MIB_MAX MAX_T(u32, UDP_MIB_MAX, TCP_MIB_MAX)
 
 /*
  *     Report socket allocation statistics [mea@utu.fi]
index e20b3705c2d2accedad4aac75064c33f733a80be..5e01863be039f647947682736be662a49284b36f 100644 (file)
@@ -27,7 +27,7 @@
 #include <net/ipv6.h>
 
 #define MAX4(a, b, c, d) \
-       max_t(u32, max_t(u32, a, b), max_t(u32, c, d))
+       MAX_T(u32, MAX_T(u32, a, b), MAX_T(u32, c, d))
 #define SNMP_MIB_MAX MAX4(UDP_MIB_MAX, TCP_MIB_MAX, \
                        IPSTATS_MIB_MAX, ICMP_MIB_MAX)