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| author | Luca Dariz <luca@orpolo.org> | 2023-02-27 21:45:00 +0100 |
|---|---|---|
| committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2023-02-27 22:42:16 +0100 |
| commit | d2880baef19991270cbcdbdb22622e91815faadc (patch) | |
| tree | 4c2c3121cf2730e90b72dbb0b81183e0e191f5dd /x86_64/locore.S | |
| parent | 8d402b754f3a436dc0e7e6e7ed3b763e98379976 (diff) | |
| download | gnumach-d2880baef19991270cbcdbdb22622e91815faadc.tar.gz gnumach-d2880baef19991270cbcdbdb22622e91815faadc.tar.bz2 gnumach-d2880baef19991270cbcdbdb22622e91815faadc.zip | |
x86_64: fix user trap during syscall with an invalid user stack
* i386/i386/locore.h: user vm_offset_t in the recovery_table
* x86_64/locore.S: fix RECOVERY() location and keep user regs in %rbx,
as it seems the convention. This only applies to 32-bit userspace.
Message-Id: <20230227204501.2492152-5-luca@orpolo.org>
Diffstat (limited to 'x86_64/locore.S')
| -rw-r--r-- | x86_64/locore.S | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/x86_64/locore.S b/x86_64/locore.S index a2663aff..47d9085c 100644 --- a/x86_64/locore.S +++ b/x86_64/locore.S @@ -1157,18 +1157,18 @@ syscall_native: andq %r10,%r10 jz mach_call_call /* skip argument copy if none */ - movq R_UESP(%rbx),%rbx /* get user stack pointer */ - addq $4,%rbx /* Skip user return address */ - movq $USER_DS,%rdx /* use user data segment for accesses */ mov %dx,%fs movq %rsp,%r11 /* save kernel ESP for error recovery */ + movq R_UESP(%rbx),%rbp /* get user stack pointer */ + addq $4,%rbp /* Skip user return address */ + #define PARAM(reg,ereg) \ - RECOVER(mach_call_addr_push) \ xorq %reg,%reg ;\ - movl %fs:(%rbx),%ereg /* 1st parameter */ ;\ - addq $4,%rbx ;\ + RECOVER(mach_call_addr_push) \ + movl %fs:(%rbp),%ereg /* 1st parameter */ ;\ + addq $4,%rbp ;\ dec %r10 ;\ jz mach_call_call @@ -1179,12 +1179,12 @@ syscall_native: PARAM(r8,r8d) /* 5th parameter */ PARAM(r9,r9d) /* 6th parameter */ - lea (%rbx,%r10,4),%rbx /* point past last argument */ + lea (%rbp,%r10,4),%rbp /* point past last argument */ xorq %r12,%r12 -0: subq $4,%rbx +0: subq $4,%rbp RECOVER(mach_call_addr_push) - movl %fs:(%rbx),%r12d + movl %fs:(%rbp),%r12d pushq %r12 /* push argument on stack */ dec %r10 jnz 0b /* loop for all arguments */ @@ -1208,7 +1208,7 @@ mach_call_call: /* * Address out of range. Change to page fault. - * %esi holds failing address. + * %rsi holds failing address. */ mach_call_addr_push: movq %r11,%rsp /* clean parameters from stack */ |