Imbus/xv6-riscv-kernel
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Use simple linker script to force data segment to be page aligned

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This commit is contained in:
Frans Kaashoek 2022-08-23 10:54:40 -04:00
parent cef1b57d4a
commit 4cd4d194b8
3 changed files with 43 additions and 9 deletions
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14
kernel/exec.c
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@ -7,7 +7,7 @@
#include "defs.h"
#include "elf.h"
static int loadseg(pde_t *, uint64, uint, struct inode *, uint, uint);
static int loadseg(pde_t *, uint64, struct inode *, uint, uint);
int flags2perm(int flags)
{
@ -59,15 +59,13 @@ exec(char *path, char **argv)
goto bad;
if(ph.vaddr + ph.memsz < ph.vaddr)
goto bad;
if(ph.align != PGSIZE)
if(ph.vaddr % PGSIZE != 0)
goto bad;
uint64 e = PGROUNDUP(ph.vaddr + ph.memsz);
uint64 sz1;
if((sz1 = uvmalloc(pagetable, sz, e, flags2perm(ph.flags))) == 0)
if((sz1 = uvmalloc(pagetable, sz, ph.vaddr + ph.memsz, flags2perm(ph.flags))) == 0)
goto bad;
sz = sz1;
uint64 s = PGROUNDDOWN(ph.vaddr);
if(loadseg(pagetable, s, ph.vaddr - s, ip, ph.off, ph.filesz) < 0)
if(loadseg(pagetable, ph.vaddr, ip, ph.off, ph.filesz) < 0)
goto bad;
}
iunlockput(ip);
@ -147,7 +145,7 @@ exec(char *path, char **argv)
// and the pages from va to va+sz must already be mapped.
// Returns 0 on success, -1 on failure.
static int
loadseg(pagetable_t pagetable, uint64 va, uint poff, struct inode *ip, uint offset, uint sz)
loadseg(pagetable_t pagetable, uint64 va, struct inode *ip, uint offset, uint sz)
{
uint i, n;
uint64 pa;
@ -160,7 +158,7 @@ loadseg(pagetable_t pagetable, uint64 va, uint poff, struct inode *ip, uint offs
n = sz - i;
else
n = PGSIZE;
if(readi(ip, 0, (uint64)pa+poff, offset+i, n) != n)
if(readi(ip, 0, (uint64)pa, offset+i, n) != n)
return -1;
}