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Use anonymous unions and structs to organize shared space in mbuf(9),

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instead of preprocessor macros.
  This will make debugger output of 'print *m' exactly match the names
we use in code, making life of a kernel hacker way more pleasant. And
this also allows to rename struct_m_ext back to m_ext.
This commit is contained in:
Gleb Smirnoff 2015-02-17 20:52:51 +00:00
parent 5508fc88ba
commit ee52391ebe
2 changed files with 12 additions and 16 deletions
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4
sys/kern/uipc_mbuf.c
View File

@ -112,11 +112,11 @@ CTASSERT(offsetof(struct mbuf, m_pktdat) % 8 == 0);
#if defined(__LP64__)
CTASSERT(offsetof(struct mbuf, m_dat) == 32);
CTASSERT(sizeof(struct pkthdr) == 56);
CTASSERT(sizeof(struct struct_m_ext) == 48);
CTASSERT(sizeof(struct m_ext) == 48);
#else
CTASSERT(offsetof(struct mbuf, m_dat) == 24);
CTASSERT(sizeof(struct pkthdr) == 48);
CTASSERT(sizeof(struct struct_m_ext) == 28);
CTASSERT(sizeof(struct m_ext) == 28);
#endif
/*

24
sys/sys/mbuf.h
View File

@ -65,8 +65,8 @@
* they are sensible.
*/
struct mbuf;
#define MHSIZE offsetof(struct mbuf, M_dat.M_databuf)
#define MPKTHSIZE offsetof(struct mbuf, M_dat.MH.MH_dat.MH_databuf)
#define MHSIZE offsetof(struct mbuf, m_dat)
#define MPKTHSIZE offsetof(struct mbuf, m_pktdat)
#define MLEN ((int)(MSIZE - MHSIZE))
#define MHLEN ((int)(MSIZE - MPKTHSIZE))
#define MINCLSIZE (MHLEN + 1)
@ -160,7 +160,7 @@ struct pkthdr {
* Compile-time assertions in uipc_mbuf.c test these values to ensure that
* they are correct.
*/
struct struct_m_ext {
struct m_ext {
volatile u_int *ext_cnt; /* pointer to ref count info */
caddr_t ext_buf; /* start of buffer */
uint32_t ext_size; /* size of buffer, for ext_free */
@ -211,19 +211,15 @@ struct mbuf {
*/
union {
struct {
struct pkthdr MH_pkthdr; /* M_PKTHDR set */
struct pkthdr m_pkthdr; /* M_PKTHDR set */
union {
struct struct_m_ext MH_ext; /* M_EXT set */
char MH_databuf[0];
} MH_dat;
} MH;
char M_databuf[0]; /* !M_PKTHDR, !M_EXT */
} M_dat;
struct m_ext m_ext; /* M_EXT set */
char m_pktdat[0];
};
};
char m_dat[0]; /* !M_PKTHDR, !M_EXT */
};
};
#define m_pkthdr M_dat.MH.MH_pkthdr
#define m_ext M_dat.MH.MH_dat.MH_ext
#define m_pktdat M_dat.MH.MH_dat.MH_databuf
#define m_dat M_dat.M_databuf
/*
* mbuf flags of global significance and layer crossing.