From: Linus Torvalds torvalds@linux-foundation.org
[ Upstream commit 4477b39c32fdc03363affef4b11d48391e6dc9ff ]
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.co... 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 --- arch/x86/mm/pgtable.c | 2 +- drivers/edac/sb_edac.c | 4 ++-- drivers/gpu/drm/drm_color_mgmt.c | 2 +- drivers/md/dm-integrity.c | 6 +++--- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +- net/ipv4/proc.c | 2 +- net/ipv6/proc.c | 2 +- 7 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index b18f5a71e679..98aa303ad054 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -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) diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c index 0c779a0326b6..6c3a40e6f4c6 100644 --- a/drivers/edac/sb_edac.c +++ b/drivers/edac/sb_edac.c @@ -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 { diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index d021497841b8..3969dc548cff 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -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;
diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 1e27a5bce2d9..0bd76f8d4dc6 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1794,7 +1794,7 @@ static void integrity_metadata(struct work_struct *w) struct bio *bio = dm_bio_from_per_bio_data(dio, sizeof(struct dm_integrity_io)); char *checksums; unsigned int extra_space = unlikely(digest_size > ic->tag_size) ? digest_size - ic->tag_size : 0; - char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)]; + char checksums_onstack[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)]; sector_t sector; unsigned int sectors_to_process;
@@ -2073,7 +2073,7 @@ static bool __journal_read_write(struct dm_integrity_io *dio, struct bio *bio, } while (++s < ic->sectors_per_block); #ifdef INTERNAL_VERIFY if (ic->internal_hash) { - char checksums_onstack[max_t(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)]; + char checksums_onstack[MAX_T(size_t, HASH_MAX_DIGESTSIZE, MAX_TAG_SIZE)];
integrity_sector_checksum(ic, logical_sector, mem + bv.bv_offset, checksums_onstack); if (unlikely(memcmp(checksums_onstack, journal_entry_tag(ic, je), ic->tag_size))) { @@ -2638,7 +2638,7 @@ 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); diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index ff5389a8efc3..f3155d69a013 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2841,7 +2841,7 @@ 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))) diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index a85b0aba3646..b444767b15a5 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -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] diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c index 6d1d9221649d..752327b10dde 100644 --- a/net/ipv6/proc.c +++ b/net/ipv6/proc.c @@ -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)