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| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2007-01-06 22:53:48 (GMT) |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-01-06 22:53:48 (GMT) |
| commit | db6ccbb61c1291c8aaefadcc8304444f27eeb88d (patch) | |
| tree | 196718a54ccd89fe12c48383a15e0639f8ddf939 /arch/arm | |
| parent | 4ac941d2d04ef26a91adf677f3a371818596305d (diff) | |
| download | linux-db6ccbb61c1291c8aaefadcc8304444f27eeb88d.tar.xz | |
[ARM] Fix kernel-mode undefined instruction aborts
If the kernel attempts to execute a CP1 or CP2 instruction and it
aborts, and a FP emulator is not loaded, we try to return as if to
a user context, instead of the proper kernel context. Since the
fault came from kernel mode, we must use the kernel return paths.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/kernel/entry-armv.S | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 2db42b1..8517c3c 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -436,7 +436,7 @@ __und_usr: usr_entry tst r3, #PSR_T_BIT @ Thumb mode? - bne fpundefinstr @ ignore FP + bne __und_usr_unknown @ ignore FP sub r4, r2, #4 @ @@ -448,7 +448,7 @@ __und_usr: @ 1: ldrt r0, [r4] adr r9, ret_from_exception - adr lr, fpundefinstr + adr lr, __und_usr_unknown @ @ fallthrough to call_fpe @ @@ -476,7 +476,9 @@ __und_usr: * Emulators may wish to make use of the following registers: * r0 = instruction opcode. * r2 = PC+4 + * r9 = normal "successful" return address * r10 = this threads thread_info structure. + * lr = unrecognised instruction return address */ call_fpe: tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27 @@ -545,10 +547,12 @@ do_fpe: .data ENTRY(fp_enter) - .word fpundefinstr + .word no_fp .text -fpundefinstr: +no_fp: mov pc, lr + +__und_usr_unknown: mov r0, sp adr lr, ret_from_exception b do_undefinstr |